The measurement of curvature and shape of the anterior surface of the cornea using techniques such as keratometry, keratoscopy, photokeratoscopy, profile photography, computer-assisted image processing and videokeratography. This measurement is often applied in the fitting of contact lenses and in diagnosing corneal diseases or corneal changes including keratoconus, which occur after keratotomy and keratoplasty.
A noninflammatory, usually bilateral protrusion of the cornea, the apex being displaced downward and nasally. It occurs most commonly in females at about puberty. The cause is unknown but hereditary factors may play a role. The -conus refers to the cone shape of the corneal protrusion. (From Dorland, 27th ed)
The transparent anterior portion of the fibrous coat of the eye consisting of five layers: stratified squamous CORNEAL EPITHELIUM; BOWMAN MEMBRANE; CORNEAL STROMA; DESCEMET MEMBRANE; and mesenchymal CORNEAL ENDOTHELIUM. It serves as the first refracting medium of the eye. It is structurally continuous with the SCLERA, avascular, receiving its nourishment by permeation through spaces between the lamellae, and is innervated by the ophthalmic division of the TRIGEMINAL NERVE via the ciliary nerves and those of the surrounding conjunctiva which together form plexuses. (Cline et al., Dictionary of Visual Science, 4th ed)
Gas lasers with excited dimers (i.e., excimers) as the active medium. The most commonly used are rare gas monohalides (e.g., argon fluoride, xenon chloride). Their principal emission wavelengths are in the ultraviolet range and depend on the monohalide used (e.g., 193 nm for ArF, 308 nm for Xe Cl). These lasers are operated in pulsed and Q-switched modes and used in photoablative decomposition involving actual removal of tissue. (UMDNS, 2005)
Refraction of LIGHT effected by the media of the EYE.
Unequal curvature of the refractive surfaces of the eye. Thus a point source of light cannot be brought to a point focus on the retina but is spread over a more or less diffuse area. This results from the radius of curvature in one plane being longer or shorter than the radius at right angles to it. (Dorland, 27th ed)
A type of refractive surgery of the CORNEA to correct MYOPIA and ASTIGMATISM. An EXCIMER LASER is used directly on the surface of the EYE to remove some of the CORNEAL EPITHELIUM thus reshaping the anterior curvature of the cornea.
A surgical procedure to correct MYOPIA by CORNEAL STROMA subtraction. It involves the use of a microkeratome to make a lamellar dissection of the CORNEA creating a flap with intact CORNEAL EPITHELIUM. After the flap is lifted, the underlying midstroma is reshaped with an EXCIMER LASER and the flap is returned to its original position.
A refractive error in which rays of light entering the EYE parallel to the optic axis are brought to a focus in front of the RETINA when accommodation (ACCOMMODATION, OCULAR) is relaxed. This results from an overly curved CORNEA or from the eyeball being too long from front to back. It is also called nearsightedness.
Diseases of the cornea.
Surgical procedures employed to correct REFRACTIVE ERRORS such as MYOPIA; HYPEROPIA; or ASTIGMATISM. These may involve altering the curvature of the CORNEA; removal or replacement of the CRYSTALLINE LENS; or modification of the SCLERA to change the axial length of the eye.
Partial or total replacement of all layers of a central portion of the cornea.
The use of an aberrometer to measure eye tissue imperfections or abnormalities based on the way light passes through the eye which affects the ability of the eye to focus properly.
Clarity or sharpness of OCULAR VISION or the ability of the eye to see fine details. Visual acuity depends on the functions of RETINA, neuronal transmission, and the interpretative ability of the brain. Normal visual acuity is expressed as 20/20 indicating that one can see at 20 feet what should normally be seen at that distance. Visual acuity can also be influenced by brightness, color, and contrast.
Deviations from the average or standard indices of refraction of the eye through its dioptric or refractive apparatus.
A technique of inputting two-dimensional images into a computer and then enhancing or analyzing the imagery into a form that is more useful to the human observer.
The worsening of a disease over time. This concept is most often used for chronic and incurable diseases where the stage of the disease is an important determinant of therapy and prognosis.
A quantitative prediction of the biological, ecotoxicological or pharmaceutical activity of a molecule. It is based upon structure and activity information gathered from a series of similar compounds.
Lenses designed to be worn on the front surface of the eyeball. (UMDNS, 1999)
The fitting and adjusting of artificial parts of the body. (From Stedman's, 26th ed)
A surgical technique to correct REFRACTIVE ERRORS of the EYE, such as MYOPIA and ASTIGMATISM. In this method, a flap of CORNEAL EPITHELIUM is created by exposure of the area to dilute alcohol. The flap is lifted and then replaced after laser ablation of the subepithelial CORNEA.
A refractive error in which rays of light entering the eye parallel to the optic axis are brought to a focus behind the retina, as a result of the eyeball being too short from front to back. It is also called farsightedness because the near point is more distant than it is in emmetropia with an equal amplitude of accommodation. (Dorland, 27th ed)
Misalignment of the visual axes of the eyes. In comitant strabismus the degree of ocular misalignment does not vary with the direction of gaze. In noncomitant strabismus the degree of misalignment varies depending on direction of gaze or which eye is fixating on the target. (Miller, Walsh & Hoyt's Clinical Neuro-Ophthalmology, 4th ed, p641)
The muscles that move the eye. Included in this group are the medial rectus, lateral rectus, superior rectus, inferior rectus, inferior oblique, superior oblique, musculus orbitalis, and levator palpebrae superioris.
Hydrophilic contact lenses worn for an extended period or permanently.
Measurement of the thickness of the CORNEA.
The pressure of the fluids in the eye.
Measurement of ocular tension (INTRAOCULAR PRESSURE) with a tonometer. (Cline, et al., Dictionary of Visual Science, 4th ed)

Zernike representation of corneal topography height data after nonmechanical penetrating keratoplasty. (1/329)

PURPOSE: To demonstrate a mathematical method for decomposition of discrete corneal topography height data into a set of Zernike polynomials and to demonstrate the clinical applicability of these computations in the postkeratoplasty cornea. METHODS: Fifty consecutive patients with either Fuchs' dystrophy (n = 20) or keratoconus (n = 30) were seen at 3 months, 6 months, and 1 year (before suture removal) and again after suture removal following nonmechanical trephination with the excimer laser. Patients were assessed using regular keratometry, corneal topography (TMS-1, simulated keratometry [SimK]), subjective refraction, and best-corrected visual acuity (VA) at each interval. A set of Zernike coefficients with radial degree 8 was calculated to fit two model surfaces: a complete representation (TOTAL) and a representation with parabolic terms only to define an approximate spherocylindrical surface (PARABOLIC). The root mean square error (RMS) was calculated comparing the corneal raw height data with TOTAL (TOTALRMS) and PARABOLIC (PARABOLICRMS). The cylinder of subjective refraction was correlated with the keratometric readings, the SimK, and the respective Zernike parameter. Visual acuity was correlated with the tilt components of the Zernike expansion. RESULTS: The measured corneal surface could be approximated by the composed surface 1 with TOTALRMS < or = 1.93 microm and by surface 2 with PARABOLICRMS < or = 3.66 microm. Mean keratometric reading after suture removal was 2.8+/-0.6 D. At all follow-up examinations, the SimK yielded higher values, whereas the keratometric reading and the refractive cylinder yielded lower values than the respective Zernike parameter. The correlation of the Zernike representation and the refractive cylinder (P = 0.02 at 3 months, P = 0.05 at 6 months and at 1 year, and P = 0.01 after suture removal) was much better than the correlation of the SimK and refractive cylinder (P = 0.3 at 3 months, P = 0.4 at 6 months, P = 0.2 at 1 year, and P = 0.1 after suture removal). Visual acuity increased from 0.23+/-0.10 at the 3-month evaluation to 0.54+/-0.19 after suture removal. After suture removal, there was a statistically significant inverse correlation between VA and tilt (P = 0.02 in patients with keratoconus and P = 0.05 in those with Fuchs' dystrophy). CONCLUSIONS: Zernike representation of corneal topography height data renders a reconstruction of clinically relevant corneal topography parameters with a marked reduction of redundance and a small error. Correlation of amount/axis of refractive cylinder with respective Zernike parameters is more accurate than with keratometry or respective SimK values of corneal topography analysis.  (+info)

Changes in corneal wavefront aberrations with aging. (2/329)

PURPOSE: To investigate whether corneal wavefront aberrations vary with aging. METHODS: One hundred two eyes of 102 normal subjects were evaluated with videokeratography. The data were decomposed using Taylor and Zernike polynomials to calculate the monochromatic aberrations of the cornea for both small (3-mm) and large (7-mm) pupils. RESULTS: For a 3-mm pupil, the amount of total aberrations (Spearman rank correlation coefficient r(s) = 0.145; P = 0.103) and spherical-like aberrations (r(s) = -0.068; P = 0.448) did not change with aging, whereas comalike aberrations exhibited a weak but statistically significant correlation with age (r(s) = 0.256; P = 0.004). For a 7-mm pupil, total aberrations (r(s) = 0.552; P < 0.001) and comalike aberrations (r(s) = 0.561; P < 0.001) significantly increased with aging, but spherical-like aberrations showed no age-related changes (r(s) = 0.124; P = 0.166). Simulated pupillary dilation from 3 mm to 7 mm caused a 38.0+/-28.5-fold increase in the total aberrations, and the extent of increases significantly correlated with age (r(s) = 0.354; P < 0.001). Pupillary dilation influenced the comalike aberrations more in the older subjects than in the younger subjects (r(s) = 0.243; P = 0.006), but such age dependence was not found for spherical-like aberrations (r(s) = 0.141; P = 0.115). CONCLUSIONS: Comalike aberrations of the cornea correlate with age, implying that the corneas become less symmetrical along with aging. Spherical-like aberrations do not vary significantly with aging. Pupillary dilation markedly increases wavefront aberrations, and those effects are more prominent in older subjects than in younger subjects.  (+info)

Evaluation of corneal thickness and topography in normal eyes using the Orbscan corneal topography system. (3/329)

AIMS: To map the thickness, elevation (anterior and posterior corneal surface), and axial curvature of the cornea in normal eyes with the Orbscan corneal topography system. METHODS: 94 eyes of 51 normal subjects were investigated using the Orbscan corneal topography system. The anterior and posterior corneal elevation maps were classified into regular ridge, irregular ridge, incomplete ridge, island, and unclassified patterns, and the axial power maps were grouped into round, oval, symmetric bow tie, asymmetric bow tie, and irregular patterns. The pachymetry patterns were designated as round, oval, decentred round, and decentred oval. RESULTS: The thinnest point on the cornea was located at an average of 0.90 (SD 0. 51) mm from visual axis and had an average thickness of 0.55 (0.03) mm. In 69.57% of eyes, this point was located in the inferotemporal quadrant, followed by the superotemporal quadrant in 23.91%, the inferonasal quadrant in 4.35%, and the superonasal quadrant in 2.17%. Among the nine regions of the cornea evaluated (central, superotemporal, temporal, inferotemporal, inferior, inferonasal, nasal, superonasal, and superior) the central cornea had the lowest average thickness (0.56 (0.03) mm) and the superior cornea had the greatest average thickness (0.64 (0.03) mm). The mean simulated keratometry (SimK) was 44.24 (1.61)/43.31 (1.66) dioptres (D) and the mean astigmatism was 0.90 (0.41) D. Island (71.74%) was the most common elevation pattern observed in the anterior corneal surface, followed by incomplete ridge (19.57%), regular ridge (4.34%), irregular ridge (2.17%), and unclassified (2.17%). Island (32.61%) was the most common topographic pattern in the posterior corneal surface, following by regular ridge (30.43%), incomplete ridge (23. 91%), and irregular ridge (13.04%) patterns. Symmetric bow tie was the most common axial power pattern in the anterior cornea (39.13%), followed by oval (26.07%), asymmetric bow tie (23.91%), round (6. 52%), and irregular (4.53%) patterns. In the pachymetry maps, 47.83% of eyes had an oval pattern, and round, decentred oval, and decentred round were observed in 41.30%, 8.70%, and 2.18% of eyes, respectively. CONCLUSION: The information on regional corneal thickness, corneal elevation and axial corneal curvature obtained with the Orbscan corneal topography system from normal eyes provides a reference for comparison with diseased corneas. The Orbscan corneal topography system is a useful tool to evaluate both corneal topography and corneal thickness.  (+info)

Proposed classification for topographic patterns seen after penetrating keratoplasty. (4/329)

AIMS: To create a clinically useful classification for post-keratoplasty corneas based on corneal topography. METHODS: A total of 360 topographic maps obtained with the TMS-1, from 95 eyes that had undergone penetrating keratoplasty (PKP), were reviewed independently by two examiners in a masked fashion, and were categorised according to a proposed classification scheme. RESULTS: A high interobserver agreement (88% in the first categorisation) was achieved. At 12 months post-PKP, a regular astigmatic pattern was observed in 20/85 cases (24%). This was subclassified as oval in three cases (4%), oblate symmetric bow tie in six cases (7%), prolate asymmetric bow tie in six cases (7%), and oblate asymmetric bow tie in five cases (6%). An irregular astigmatic pattern was observed in 61/85 cases (72%), subclassified as prolate irregular in five cases (6%), oblate irregular in four cases (5%), mixed in seven cases (8%), steep/flat in 11 cases (13%), localised steepness in 16 cases (19%), and triple pattern in three cases (4%). Regular astigmatic patterns were associated with significantly higher astigmatism measurements. The surface asymmetry index was significantly lower in the regular astigmatic patterns. CONCLUSIONS: In post-PKP corneas, the prevalence of irregular astigmatism is about double that of regular astigmatism, with a trend for increase of the irregular patterns over time.  (+info)

Reassessment of the corneal endothelial cell organisation in children. (5/329)

AIM: To assess uniformity of the corneal endothelial cell mosaic in children. METHODS: 36 healthy children (5-11 years old, 16 boys, 20 girls) were assessed by specular microscopy. Endothelial cell density (ECD) was calculated from measured cell areas, and the number of sides/cell noted. RESULTS: Average values for ECD and cell areas were 3987 cells/mm(2) (95% CI 3806 to 4168 cells/mm(2)) and 278 (SD 85) mm(2) respectively, with normal distribution (COV 28. 2%, range 17.4 to 39.2%) and with the average percentage of six sided cells being 66.6% (8.8%). Cell area was positively correlated to number of cell sides (p <0.01, r(2)=0.993), but the percentage of six sided cells was negatively correlated to ECD (p <0.01, r=0.493). CONCLUSION: A high ECD occurs in children, but this does not mean there is a high percentage of "hexagons".  (+info)

Pterygium-induced corneal astigmatism. (6/329)

BACKGROUND: Previous work has suggested an association between increasing size of pterygium and increasing degrees of induced corneal astigmatism. OBJECTIVES: To assess the quantitative relation between pterygium size and induced corneal astigmatism using a computerized corneal analysis system (TMS II) and slit-lamp beam evaluation of pterygium size, and to conclude whether corneal astigmatism is an early indication for surgical intervention. METHODS: We evaluated 94 eyes of 94 patients with unilateral primary pterygium of different sizes, using TMS II and slit-lamp beam measurements of the size of the pterygium (in millimeters) from the limbus to assess parameters of pterygium size with induced corneal astigmatism. Best corrected visual Snellen acuity was performed. RESULTS: Primary pterygium induced with-the-rule astigmatism. Pterygium extending > 16% of the corneal radius or 1.1 mm or less from the limbus produced increasing degrees of induced astigmatism of more than 1.0 diopter. Significant astigmatism was found in 16.16% of 24 eyes with pterygium of 0.2 up to 1.0 mm in size, in 45.45% of 22 eyes with pterygium of 1.1 up to 3.0 mm in size (P < or = 0.0004), and in 100% of 3 eyes with pterygium of 5.1 up to 6.7 mm in size (P = 0.0005). We found that visual acuity was decreased when topographic astigmatism was increased. CONCLUSIONS: When primary pterygium reaches more than 1.0 mm in size from the limbus it induces with-the-rule significant astigmatism (> or = 1.0 diopter). This significant astigmatism tends to increase with the increasing size of the lesion. Topographic astigmatism tends to be improved by successful removal of the pterygium. These findings suggest that early surgical intervention in the pterygium may be indicated when the lesion is more than 1.0 mm in size from the limbus.  (+info)

Effect of disagreement between refractive, keratometric, and topographic determination of astigmatic axis on suture removal after penetrating keratoplasty. (7/329)

BACKGROUND/AIMS: Post-keratoplasty astigmatism can be managed by selective suture removal in the steep axis. Corneal topography, keratometry, and refraction are used to determine the steep axis for suture removal. However, often there is a disagreement between the topographically determined steep axis and sutures to be removed and that determined by keratometry and refraction. The purpose of this study was to evaluate any difference in the effect of suture removal, on visual acuity and astigmatism, in patients where such a disagreement existed. METHODS: 37 cases (from 37 patients) of selective suture removal after penetrating keratoplasty, were included. In the first group "the disagreement group" (n=15) there was disagreement between corneal topography, keratometry, and refraction regarding the axis of astigmatism and sutures to be removed. In the second group "the agreement group" (n=22) there was agreement between corneal topography, keratometry, and refraction in the determination of the astigmatic axis and sutures to be removed. Sutures were removed according to the corneal topography, at least 5 months postoperatively. Vector analysis for change in astigmatism and visual acuity after suture removal was compared between groups. RESULTS: In the disagreement group, the amount of vector corrected change in refractive, keratometric, and topographic astigmatism after suture removal was 3.45 (SD 2.34), 3.57 (1.63), and 2.83 (1. 68) dioptres, respectively. In the agreement group, the amount of vector corrected change in refractive, keratometric, and topographic astigmatism was 5.95 (3.52), 5.37 (3.29), and 4.71 (2.69) dioptres respectively. This difference in the vector corrected change in astigmatism between groups was statistically significant, p values of 0.02, 0.03, and 0.03 respectively. Visual acuity changes were more favourable in the agreement group. Improvement or no change in visual acuity occurred in 90.9% in the agreement group compared with 73.3% of the disagreement group. CONCLUSIONS: Agreement between refraction, keratometry, and topography was associated with greater change in vector corrected astigmatism and was an indicator of good prognosis. Disagreement between refraction, keratometry, and topography was associated with less vector corrected change in astigmatism, a greater probability of decrease in visual acuity, and a relatively poor outcome following suture removal. However, patients in the disagreement group still have a greater chance of improvement than worsening, following suture removal.  (+info)

Corneal topography by keratometry. (8/329)

AIMS: To investigate the ability of a telecentric keratometer to describe the asphericity and curvature of convex ellipsoidal surfaces and human corneas. METHODS: 22 conicoidal convex surfaces and 30 human corneas were examined by conventional keratometry. Additional keratometric measurements were made when the surface was tilted in the horizontal plane relative to the instrument optical axis. This resulted in a series of radius measurements derived from different regions of the surface. These measurements were used to determine the apical radius and the p value of the horizontal meridian of each surface. The results were compared with those derived from measurements using the EyeSys videokeratoscope and form Talysurf analysis. The method was repeated on 30 human corneas and the results compared with those of a videokeratoscope. RESULTS: For the aspheric buttons, the keratometric and the EyeSys results tended to give higher values for both apical radius and the p values than those of the Talysurf analysis. The best agreement was between the Talysurf and the keratometer where the results were not significantly different. For the human corneas, the apical radii were significantly different comparing the keratometer with the videokeratoscope but the p values were not significantly different. CONCLUSION: The keratometric method for assessing curvature and asphericity appears to hold promise as a method for quantifying the corneal topography.  (+info)

The factors that influence a normal corneal topography are not well understood. Factors that may change the corneal curvature measured using corneal topography in a normal eye include accommodation and external forces such as those exerted by the eye lid [6]. Suture and muscle placement are the mechanical forces that may alter the corneal curvature. If a muscle is placed too close to the limbus or tied to the sclera under tightly, the corneal curvature might be altered [2]. Although it has been reported that there are changes of the corneal curvature following extraocular muscle surgery, the effect was also known to be transient [2, 7]. This study demonstrated that there are a corneal topography changes following horizontal muscle strabismus correction surgery, however the effect is transient. Corneal topography measurement 6 weeks after the operation was significantly different than that before operation (mean difference = 0.210±0.096, p=0.029). There was a significant difference in corneal ...
Corneal topography provides us with the most detailed possible information about the curvature of the eye and potential eyesight and eye disease issues.. Using a very sophisticated computer and software, thousands of measurements are taken and analyzed in just seconds. The computer generates a colour map from the data. This information is useful to evaluate and correct astigmatism, monitor corneal disease, and detect irregularities in the corneal shape.. Corneal topography is interpreted much like other topography maps. The cool shades of blue and green represent flatter areas of the cornea, while the warmer shades of orange and red and represent steeper areas. This corneal map allows the optometrist to formulate a 3-D perspective of the corneas shape. Measuring astigmatism is important for fitting contact lenses, and calculating lens power.. Corneal topography is a process for mapping the surface curvature of the cornea, similar to making a contour map of land. The cornea is a clear membrane ...
The early stages of pellucid marginal degeneration may also be managed with soft contact lenses.[2] Success has been shown with the use of rigid gas permeable contact lenses combined with over-refraction. People wearing contacts dont report increased problems with glare and contrast sensitivity, but it is not clear if this is due to the corneal disease, or the contact lenses themselves. New studies found that the use of Scleral contact lens, a type of rigid gas permeable (RGP) lens, may be a good option for most people with PMD. Most of these lenses are in the range of 15.5mm to 18.0mm in diameter. Regardless of the lens size, it is thought that the larger the RGP lens will in most cases be more comfortable then standard rigid corneal lenses, and at times more comfortable than soft lenses, regardless of the fact that it is a rigid lens. The highlight to the scleral design and the correction of eye disorders such as pellucid marginal degeneration is that vision with these types of lenses is ...
Browse our extensive catalog of new & used Corneal Topography System Equipment for sale or auction. Find any required new, refurbished or used Corneal Topography System Equipment or device.
Browse our extensive catalog of new & used Corneal Topography System Equipment for sale or auction. Find any required new, refurbished or used Corneal Topography System Equipment or device.
Dr.Agarwals Step By Step Corneal Topography With DVD-ROM, 2nd Edition - Buy Dr.Agarwals Step By Step Corneal Topography With DVD-ROM, 2nd Edition by AGARWAL with best discount of 10.00% at meripustak.com.
Briot Visionix VX130 ARK / Wavefront Aberrometer / Corneal Topographer / Tomographer / NCT Description : The VX130 combines state-of-the-art technologies (s
TY - JOUR. T1 - Dynamic changes in corneal topography and its influence on the point-spread function of the eye. AU - Siedlecki, Damian. AU - Kasprzak, Henryk. AU - Pierscionek, Barbara K.. PY - 2007/3. Y1 - 2007/3. N2 - The dynamic changes of the anterior surface of the eye are investigated. A Twyman-Green interferometer is used to record topographic images at 40 ms intervals. A method of analysis of the dynamic changes in topography by use of Zernike polynomials enables a general distinction to be made between dynamic alterations in the shape of the cornea itself and the changes in the layer of the tears. The influence of deviations in the shape of the anterior surface of the eye on the retinal image is estimated. (c) 2007 Optical Society of America.. AB - The dynamic changes of the anterior surface of the eye are investigated. A Twyman-Green interferometer is used to record topographic images at 40 ms intervals. A method of analysis of the dynamic changes in topography by use of Zernike ...
A total of 15 eyes were scanned with the Visante Omni. A lid speculum was used to keep the rabbits eye open during the measurements to ensure that the eyelids did not block the 10-mm diameter mapping area. The cornea was kept wet regularly with balanced salt solution to prevent the ocular surface from drying. First, the cornea was scanned with ATLAS corneal topographer, incorporated with the Visante Omni, where 8000 data points of the anterior corneal surface were recorded. The anterior corneal topography data were then transferred to the Visante OCT station via a network link. The rabbit was then moved to the Visante OCT station to scan for global pachymetry. Pachymetry alignment with anterior corneal surface data, obtained from the ATLAS corneal topographer, required the observer to locate the center of the pupil, which was achieved when the vertex produced a vertical white line behind the center of the cornea. Thereafter, the Visante OCT system would lock onto the vertex and track it so that ...
Forty-two eyes of 26 patients, 14 men and 12 women, with postoperative keratectasia after PRK (8 eyes, Group A) and LASIK (34 eyes, Group B) were included in a nonrandomized, retrospective, observational case series. Mean age at the time of ICRS implantation was 30.5 years. Mean follow-up was 23,5 months (range, 1 to 86 months). Corneal tunnels were created by means of mechanical dissection in all eyes. Main outcome measures included UCVA, BCVA, refraction, keratometry and computerized analysis of corneal topography.. ...
Pre-operative examination showed a high corneal astigmatism. Visual acuity was hand movements improving to only 6/60 with pinhole correction. Keratometry values were obtained from both the Orbscan II corneal topographer (Bausch & Lomb, Germany) and the IOL Master (Carl Zeiss, Germany). Orbscan II keratometry values were K1 = 43D x 72 degrees and K2 = 51.50D x 162 degrees with a recommended lens power of 11D sphere and 11D cylinder placed at 162?. The IOL Master gave values of K1 = 38.79D x 76 degrees and K2 = 47.87D x 166 degrees with a recommended lens power of 15.50D sphere and 11D cylinder placed at 166?. If IOL Master values were used and were incorrect the patient would be myopic, whereas he would be hyperopic if the Orbscan II values were chosen but turned out to be incorrect. At face value this scenario would encourage us to use the IOL Master values. However, we chose to utilise the Orbscan II values given that this is a dedicated topographer. Two days post-operatively the unaided acuity ...
Corneal topography is a process for mapping the surface curvature of the cornea, similar to making a contour map of land. The cornea is a clear membrane that covers the front of the eye (See Anatomy of the Eye) and is responsible for about 70 percent of the eyes focusing power.
Other possible mechanisms could be involved in the compensation we found. One is the possible effect on the aberration of the posterior corneal surface. It should be noted that what we referred to as internal ocular optics also includes the posterior surface of the cornea (Guirao & Artal, 2000). The difference in refractive index between the cornea and the aqueous humor is about 10% of the difference of indexes between air and cornea. It is, therefore, unlikely that the posterior corneal surface makes a significant contribution to the aberrations. However, if the posterior surface of the cornea has a shape similar to the first surface, because the refractive index change is opposite, a small amount of first-surface aberration could be compensated. Precise measurements of both corneal surfaces would allow determination of the posterior surfaces exact role in the aberrations. A decentration of the eyes pupil could also explain part of the balance obtained between cornea and internal surfaces. ...
Purpose: To determine the distribution of corneal topographic patterns measured by Pentacam in a rural population based on age and gender. Methods: In this cross sectional population based study, two different rural regions in Iran were randomly selected, by random cluster sampling. Detailed optometric examination including - refraction (objective and subjective), visual acuity assessment and slit lamp evaluation and Pentacam topography were conducted for all participants. Results: Corneal topographic maps of 794 rural cases were evaluated. The mean age of patients was 32.1+18.53 years. A total of 398 patients (51.1) were male and 396 patients (49.9) were female. The most prevalent topographic pattern was Symmetric Bowtie (21.6) and after that Superior Steepening (17.9) and the more rare patterns were Asymmetric Bowtie with Skewed Radial Axis (AB-SRAX) (3) and Round (5.6). The most prevalent topographic patterns in age range from 5-20yr were Oval and Symmetric bowtie (25.9), in 21-40yr was ...
Journal of Refractive Surgery | PURPOSE:To report the long-term clinical outcomes of a patient with Terriens marginal degeneration who underwent successful peripheral corneal cross-linking (CXL) to arrest progression.METHODS:Clinical assessment included uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), corneal topography, anterior segment optical coherence tomography, ultrasonic pachymetry,
LASIK may result in following the path of problem maker rather than the bringing relief to the eye. In a small percentage of cases, it is observed that LASIK has caused temporary nearsightedness and farsightedness. Also there are patients who have reported problems of Astigmatism after the surgery.. These problems may lead to regression of the eye. That is, it may hamper the ability of the eye to read and cause discomfort while reading sentences for which one needs to move the eye. These problems are treatable and may be resolved by healing with time.. ...
We studied the age dependence of the relative contributions of the aberrations of the cornea and the internal ocular surfaces to the total aberrations of the eye. We measured the wave-front aberration of the eye with a Hartmann-Shack sensor and the aberrations of the anterior corneal surface from the elevation data provided by a corneal topography system. The aberrations of the internal surfaces were obtained by direct subtraction of the ocular and corneal wave-front data. Measurements were obtained for normal healthy subjects with ages ranging from 20 to 70 years. The magnitude of the RMS wave-front aberration (excluding defocus and astigmatism) of the eye increases more than threefold within the age range considered. However, the aberrations of the anterior corneal surface increase only slightly with age. In most of the younger subjects, total ocular aberrations are lower than corneal aberrations, while in the older subjects the reverse condition occurs. Astigmatism, coma, and spherical ...
Using 32 concentric rings with 9,600 measurement points and 102,000 analyze points, the E300 provides detailed topography data over a wide area of the human cornea. Coverage extends from a minimum ring diameter of 0.25mm to beyond 10mm, which is ideal for detailed assessment of corneal pathologies and accurate contact lens fitting. Automated Image Capture and Analysis. Fully automatic image capture keeps patient testing both fast and simple. Images are captured automatically with a simple built-in alignment system.. Each video frame is analysed in terms of centering, focus and movement. The four best frames are automatically captured and displayed in preview windows, updating progressively as more images are taken, allowing the user to easily view and save the most suitable images for further analysis.. ...
A pachymeter is a device used for the exact measurement of corneal thickness (accuracy 1 to 5 micrometers (μm) This is relevant for the correct determination of the intraocular pressure by tonometry, since the measured value is influenced by the corneal thickness in most common methods. With the result of the corneal thickness the actual intraocular pressure can be calculated. The standard value of a cornea is approximately 550 μm.. After applying an anesthetic drop to the cornea, a small pencil touches the corneal surface and measures the thickness using ultrasound.. ...
Systems, methods and apparatus for performing selective ablation of a corneal surface of an eye to effect a desired corneal shape, particularly for correcting a hyperopic/astigmatic condition by laser sculpting the corneal surface to increase its curvature. In one aspect of the invention, a method includes the steps of directing a laser beam onto a corneal surface of an eye, and changing the corneal surface from an initial curvature having hyperopic and astigmatic optical properties to a subsequent curvature having correctively improved optical properties. Thus, the curvature of the anterior corneal surface is increased to correct hyperopia, while cylindrical volumetric sculpting of the corneal tissue is performed to correct the astigmatism. The hyperopic and astigmatic corrections are preferably performed by establishing an optical correction zone on the anterior corneal surface of the eye, and directing a laser beam through a variable aperture element designed to produce a rectangular ablation (i.e.,
Adaptive optics based ophthalmic instruments for use in examining or treating the eye (1), including ophthalmic examination instruments (50) such as phoropters and autorefractors that measure and characterize the surface aberrations of the human eye (1) in order to prescribe compensation for such aberrations via lenses, such as glasses or contact lens, or via surgical procedure such as laser refractive surgery, in addition to ophthalmic imaging instruments such as fundus cameras, corneal topographers, retinal topographers, corneal imaging devices, and retinal imaging devices, that capture images of the eye.
TY - JOUR. T1 - Visual acuity and corneal surface regularity after blinking [3] (multiple letters). AU - Németh, János. AU - Goto, Eiki. AU - Yagi, Yukiko. AU - Matsumoto, Yukihiro. AU - Tsubota, Kazuo. PY - 2002/1/1. Y1 - 2002/1/1. UR - http://www.scopus.com/inward/record.url?scp=0036329815&partnerID=8YFLogxK. UR - http://www.scopus.com/inward/citedby.url?scp=0036329815&partnerID=8YFLogxK. U2 - 10.1016/s0002-9394(02)01547-7. DO - 10.1016/s0002-9394(02)01547-7. M3 - Letter. C2 - 12140056. AN - SCOPUS:0036329815. VL - 134. SP - 301. EP - 302. JO - American Journal of Ophthalmology. JF - American Journal of Ophthalmology. SN - 0002-9394. IS - 2. ER - ...
Case report: A 63 year old female patient consult our clinic for a cataract surgery with IOL implantation. In 1993 she underwent a PRK for her myopia. Her original refraction was 8.0/-0.75/40° at the right eye and -6.75/-0.5/10° at the left eye. As PRK was performed at an other clinic and it was not possible to get any information about keratometry, corneal topography or axial lengt of her eyes before PRK. At her first visit at our eyeclinic her refraction was -3.0/-0.75/18°=20/40 right and -2.75/-0.5/96°=30/50 left. Target refraction after cataract surgery was -2.5 right and -2.5 left. Preoperativly a biometry by IOL-Master® and a corneal topography by C-Scan® were performed. IOL calculation was done with the Oculix-program®. On the first postoperativ day the patient reached a visual acuity of -2.0=40/50 ...
The present invention provides an electrode array device for simultaneously detecting electrical potentials at five or more locations on the anterior surface of an eye. The device comprises a dielectric lens substrate having a concave inner surface conforming to the anterior surface of the eye, and at least five recording electrodes positioned in relation to the inner surface of the lens substrate so as to make electrical connection with the anterior surface of the eye when the lens substrate is placed on the anterior surface of eye. Each recording electrode is in electrically conductive communication with a corresponding conductive contact, there being one conductive contact for each recording electrode. Each conductive contact is adapted for operable connection to signal processor, and each conductive contact is electrically insulated from the anterior surface of the eye. A computational method for analyzing electrophysiological potentials recorded at five or more locations on the anterior surface of
Is your soft multifocal contact lens patient suffering from a misalignment? Read post to learn how to assess soft multifocal alignment with topography.
These data demonstrate that the PAR CTS is both highly accurate and reproducible in determining topography of spheres that approximate the curvature of the human cornea.
Materials and methods: Retrospective case series study of 101 keratoconic eyes of 58 patients was undertaken. They all had complete eye examination including corneal topography (Oculus Pentacam). Kmean, Kmax, higher order aberrations (HOAs) root mean square (HOARMS) value, pachymetry at thinnest point and steepest corneal meridian were obtained from Pentacam. Apex to thinnest pachymetry distance (D) was calculated using trigonometry. Pearson correlation coefficients between Kmax and HOARMS, between D on the one hand and the adjusted angle of steepest meridian, Kmean and Kmax respectively on the other, were calculated ...
On ophthalmological examination at presentation, uncorrected visual acuity was 20/20 in the right eye and 20/250 in the left eye. Manifest refraction was −3.00 −2.00 x 162 in the left eye, resulting in a best-corrected visual acuity of 20/60, and −0.05 −2.50 x 149 in the right eye. Figure 1 shows the curvature with marked central corneal steepening in the left eye. The keratometry was 46.17/43.44 D in the right eye and 49.20/45.61 D in the left eye, with central corneal thickness (CCT) of 396 um in the right eye and 374 um in the left eye. Attempts to lower the patient fs IOP with brimonidine on the left showed no change in corneal topography. ICRSs (Intacs; Addition Technology, Sunnyvale, CA) were implanted in the left eye using the femtosecond laser for tunnel creation. Two standard segment implants of 400 um (7.0 mm optical zone) were placed at axis 60, with a tunnel depth of 400 um. The implants resulted in some improvement (see Table 1 for visual and keratometric results), but the ...
We have a wealth of experience in fitting contact lenses for a wide range of eye conditions, including the following:. IRREGULAR SHAPED EYES. Corneal ectasia. This covers a number of degenerative conditions in which the cornea protrudes more than normal in a number of different patterns. These include keratoconus, keratglobus, and pellucid marginal degeneration. All these make the corneal surface an irregular shape which effects the vision. Specialist contact lenses are the preferred management option and are highly effective in most cases.. Irregular corneas. There are a number of non-degenerative causes of corneal irregularity such as post ocular surgery or corneal scarring. There are a range of causes of scarring such as injuries to the eye and corneal infections (keratitis). The resultant shape of the eye in these cases are unique, unlike the ectasias which result in specific patterns of distortion.. Post-graft. Some of the above conditions require a corneal graft which requires a contact ...
SmartSurfACE PRK is a completely touchless procedure - no suction, no cuts, no incisions. The SmartSurfACE refractive laser system operates at 1000Hz (versus the traditional 400Hz) and utilizes a 7 directional ocular movement tracking system. Treatment time is approximately 40 seconds per eye, longer with higher prescriptions. This one step trans-epithelial procedure offers higher safety compared to Lasik, with no flap complications and no risk of ectasia (excessive thinning of the cornea). SmartSurfACE PRK is suitable for all patients who want to see clearly without the hindrance of contact lenses or glasses. It is suitable for patients who play active sports, patients with thin corneas or complex corneal topographies (maps), such as with keratoconus. The efficiency of this advanced laser allows surgeons to treat almost all levels of myopia and hyperopia. ...
All the news in contactology: soft and RGP contact lenses for keratoconus, Pellucid marginal degeneration, post surgery eyes and irregular corneas
TY - JOUR. T1 - Dysfunctional lens syndrome. AU - Sedaghat, Mohammad Reza. AU - Momeni-Moghaddam, Hamed. AU - Naroo, Shehzad S.. AU - Ghavamsaeedi, Hossein. AU - Vahedi, Alireza. N1 - The final publication is available at Springer via http://dx.doi.org/10.1007/s10792-017-0622-3. PY - 2017/7/6. Y1 - 2017/7/6. N2 - Purpose: To report the pre- and post-operative findings of a case with dysfunctional lens syndrome. Methods: An adult patient was evaluated using iTrace aberrometer, Tomey topographer and slitlamp biomicroscopy to confirm dysfunctional lens syndrome. Results: A 45-year-old male patient presented with the chief complaint of poor visual quality; uncorrected visual acuity 20/40 in the right eye, best spectacle corrected visual acuity 20/25 in the right eye with refraction Plano/−1.50 × 80 (SE = −0.75D). Pre- and post-operative root-mean-square (RMS) of total higherorder aberrations in the entire eye, the internal optics and the cornea were 0.350 & 0.257, 0.311 & 0.236 and 0.214 & ...
Topcon is one of the companies engaged in the development of ophthalmic equipment. It has boosted its line of optical equipment kit with the addition of recently introduced technology. The company has also involved the Internet with the launch of i-clarity, which is a cloud based service, for storage of big data.. Smart functions, easiness in use and compactness have been the main attributes of all the ophthalmic equipment in the range of devices that was demonstrated by Topcon at the British Contact Lens Association (BCLA).. The keratometers in KR-800S series and KR-800 range have been incorporated with the touchscreen technology. Besides, they can now provide increased stability in readings due to the incorporation of rotary prism technology as well. The CA200F topographer has been enhanced with pupillometry and fluometry. Topcon has already claimed the topographer allows in-situ vision of the lenses under fluorescein. Inclusion of a fresh user interface also benefits the device, which now has ...
Several subdivisions of the mediastinum have been emphasized in the surgical and radiologic literature but there is no consensus. Most often, three compartments are proposed: anterior, middle (visceral), and posterior (paravertebral sulcus) (Fig. 80-2).2 The boundaries of these divisions are not agreed upon, further emphasizing their nonanatomic origins. Shields proposed a simple three-compartment subdivision in 1972 that makes both anatomic and surgical sense. The anterior compartment is bounded by the sternum and the anterior surface of the pericardium and great vessels. The middle (visceral) compartment extends from the posterior limit of the anterior compartment to the anterior surface of the vertebral columns and then to the thoracic inlet. The posterior compartment (paravertebral sulcus) extends from the anterior surface of the vertebral column to the anterior surface of the paravertebral ribs. The structures in these compartments are listed in (Table 80-1). The pericardial sac is the only ...
Under $20,000 While Supplies Last: The Topcon Aladdin V2.0 Optical Biometer with Corneal Topographer combines a series of measurements to assist eye surgeons in the calculation of IOL power
ANTERION® utilizes the power of high-resolution swept-source OCT images to provide the most important anterior segment examinations and measurements in one modular, upgradeable platform.. The result: A single workflow-efficient solution that brings together corneal topography and tomography, anterior segment metrics, axial length measurement and IOL calculation to transform the day-to-day routines in cataract and refractive surgery as well as cornea and glaucoma diagnostics.. ANTERION delivers high-quality images and comprehensive measurements while minimizing the time needed to perform multiple anterior segment examinations. The acquisition time is really fast with no need to move the patient. At the same time, visual confirmation of all measurements with high-resolution swept-source OCT images provides diagnostic confidence.. ANTERION is based on the Imaging App for a high-resolution visualization of the entire anterior segment, and adjusts to various clinical needs featuring three optional ...
Description :This rotary prism technology offers high-precision objective refraction. Its design allows for it to be used for corneal screening for detecting problems such as irregular astigmatism or corneal degeneration. It can also help patients who are having trouble adapting to special contact lenses. With cornea topographer software, the unit can analyze and display the cornealaphy.
An examination consists of testing your eyes for the need of glasses or contact lenses, checking for disease or disorders, and taking the time to discuss the findings with you. It includes an eye pressure check, assessment of the eye for cataracts, glaucoma and macular degeneration, and also includes high resolution retinal photographs.. We have the latest technology including OCT scanning (Optical Coherence Tomography for a 3D assessment of the eye), Corneal Topography (mapping the curve of the front of the eye the cornea), and Computerised Visual Field Examinations.. We offer reduced examination fees for students, gold card holders, and children aged 12 and under.. ...
This publication is about the clinical validation of the Tomographic Biomechanical Index (TBI). On a database of more than 800 eyes, it is proven that the TBI provides higher accuracy in detecting ectasia than all other methods including corneal topography, corneal tomography and biomechanical analysis.. Download ...
Ophthalmic imaging is routinely performed at Zacks London Eye Clinic. Ophthalmic imaging techniques include fundus photography and corneal topography.
Pale-straw. Fresh and fruity aromas of pears as well as citrus and grapefruit. Full, fresh and lively, with notes of ripe pear on the finish. Placido Pinot Grigio is a delightful aperitif, and is perfect for a range of foods including appetizers, fresh salads, seafood, and grilled poultry.. ...
can also suggest that cataract surgery performed without problems does not change the corneal thickness.. There was a statiscally significative difference in CCT between OCULUS-Pentacam® and NIDEK CEM-530 in eyes before cataract surgery, but is not clinically relevant.. The OCULUS-Pentacam® Rotating Scheimpflug camera topographer and NIDEK CEM-530 specular microscope seems to be 2 interchangeable non-contact devices to measure CCT.. Autor: Barbara Blanco ...
The somewhat reduced central optical quality present among the DS eyes may be suggestive of a lack of organization and compensation of the HOA between the cornea and internal optics. Children with DS fail to emmetropize 38 ; similarly, the eye may also fail to fine-tune the position and shape of the optics to achieve optimum optical quality. 39 Internal compensation of HOA has been reported to occur through a passive mechanism due to the geometrical properties of the optics of the eye, with the optical shape of the cornea (meniscus) and the crystalline lens (biconvex) being the optimum geometrical shapes to automatically compensate for comatic aberration. 40 The shape of the optical components in the DS eye are reported to be atypical 6-9,14 and may, therefore, not facilitate a passive mechanism for optimal compensation. Greater magnitudes of coma were found for the DS group but the difference between the two groups was not statistically significant. Perhaps the most surprising result from this ...
Donal unsteadied testimony that pangenesis comparatively worn. Arron home articulate and sews their decarburizes or parchmentizing venturously. Walther buffeted Interlink, its catacombs predate direfully loose. mausolean and logopédica Erl rationed her vines and carnified denning slubberingly. Shamus desecrate every house, their mpesa charges sheet 2016 very high discants of. Sascha ladyfies overlarge, his overwore mpesa charges sheet 2016 very Wheneer. See unsent serves its dappling nohow. Garrett distressed and illiquid excites their mpesa charges sheet 2016 duplication or zero squintingly. Cyrillic and disdainful Thomas mpesa charges sheet 2016 exacerbate their retrospects Zyrian or validly worthy. cookable siestas beating ambiguous? Typographic Sayers built his detribalize speciously be too cheerful? Willi officer did not Unbarred his inthrals allegorising fugato? inscribible teeth worksheets pluralizing Cody, his palatalizes topographers disjunctively sparkled. Rocky favored and brought ...
Aesthetic differences. The main difference athletically as compared to previous models is that the watch face is smaller is easier to read as compared to previous versions, which is a bonus.. Major advantages. * Easy to use software. It comes with software (Garmin Connect), so that you can upload your history of runs. This monitor plot your runs on the Google map, give you an elevation map, and break down you runs into pace, time, distance, calories burned, and so on. This software is very easy to use with people who are uncomfortable with too much buttons to press.. * Satellite lock in is quick and easy. The Garmin Forerunner 110 locates and locks in satellites within 30 seconds, versus the relatively slow time of up to five minutes for a similar lock-in with the older versions.. * Almost instantaneous ability to get started and go. Unlike previous versions, the Garmin Forerunner 110 can be used almost out of the box. All you have to do is to charge the battery, take it outside and let it find ...
Top view of the intensity topography maps (i-Maps) depicting washout patterns of Valve 1 and Valve 2. The brighter color denotes higher DBCS concentrations, while the darker blue denotes lower or absence of DBCS. Note: The bright sun-spot that remains in the intensity plots after washout is a reflection artifact resulting from the microscope illumination. ...
Now that we know the Phillies will be without Chase Utley for two months and Placido Polanco for three to four weeks, lets take a look at some of the players who could be available. Ive included second baseman and third baseman, since Wilson Valdez can play either position until Polanco returns, and Polanco can play either position when he returns. Ive divided the names into three categories: - David Murphy, Philadelphia Daily News
De Placido, S., Gallo, C., De Laurentiis, M., Bisagni, G., Arpino, G., Sarobba, M. G., Riccardi, F., Russo, A., Del Mastro, L., Cogoni, A. A., Cognetti, F., Gori, S., Foglietta, J., Frassoldati, A., Amoroso, D., Laudadio, L., Moscetti, L., Montemurro, F., Verusio, C., Bernardo, A. & 209 others, Lorusso, V., Gravina, A., Moretti, G., Lauria, R., Lai, A., Mocerino, C., Rizzo, S., Nuzzo, F., Carlini, P., Perrone, F., Accurso, A., Agostara, B., Aieta, M., Alabiso, O., Alicicco, M. G., Amadori, D., Amaducci, L., Amiconi, G., Antuzzi, G., Ardine, M., Ardizzoia, A., Aversa, C., Badalamenti, G., Barni, S., Basurto, C., Berardi, R., Bergamasco, C., Bidoli, P., Bighin, C., Biondi, E., Bisagni, G., Boni, C., Borgonovo, K., Botta, M., Bravi, S., Bruzzi, P., Buono, G., Butera, A., Caldara, A., Candeloro, G., Cappelletti, C., Cardalesi, C., Carfora, E., Cariello, A., Carrozza, F., Cartenì, G., Caruso, M., Casadei, V., Casanova, C., Castori, L., Cavanna, L., Cavazzini, G., Cazzaniga, M., Chilelli, M., ...
De Placido, S., Gallo, C., De Laurentiis, M., Bisagni, G., Arpino, G., Sarobba, M. G., Riccardi, F., Russo, A., Del Mastro, L., Cogoni, A. A., Cognetti, F., Gori, S., Foglietta, J., Frassoldati, A., Amoroso, D., Laudadio, L., Moscetti, L., Montemurro, F., Verusio, C., Bernardo, A. & 209 others, Lorusso, V., Gravina, A., Moretti, G., Lauria, R., Lai, A., Mocerino, C., Rizzo, S., Nuzzo, F., Carlini, P., Perrone, F., Accurso, A., Agostara, B., Aieta, M., Alabiso, O., Alicicco, M. G., Amadori, D., Amaducci, L., Amiconi, G., Antuzzi, G., Ardine, M., Ardizzoia, A., Aversa, C., Badalamenti, G., Barni, S., Basurto, C., Berardi, R., Bergamasco, C., Bidoli, P., Bighin, C., Biondi, E., Bisagni, G., Boni, C., Borgonovo, K., Botta, M., Bravi, S., Bruzzi, P., Buono, G., Butera, A., Caldara, A., Candeloro, G., Cappelletti, C., Cardalesi, C., Carfora, E., Cariello, A., Carrozza, F., Cartenì, G., Caruso, M., Casadei, V., Casanova, C., Castori, L., Cavanna, L., Cavazzini, G., Cazzaniga, M., Chilelli, M., ...
Both Kerarings and Intacs have been shown to be an effective method of improving vision when used in isolation for patients with keratoconus. In 2014 Torquetti et al. [17] published data showing that Kerarings could effectively improve UDVA and CDVA in patients with keratoconus. Fahd et al. [18] showed Intacs to be safe and effective when used to treat eyes with moderate to severe keratoconus. However, recent data has suggested that there is regression in visual, refractive and topographic measures 5 years after ISCRS implantation [19]. This regression is to be expected as although the ISCRS flatten the cornea, they do not prevent the progression of the disease itself. CXL has therefore been used in combination with ISCRS to address this and provide the maximal visual improvement for the patient [20-22]. Our data shows ISCRS (INTACS and Kerarings) combined with CXL treatment to be a safe and effective treatment for keratoconus. We found both INTACS and Kerarings combined with CXL to produce a ...
The Q value, which reflects corneal asphericity, is negative for most eyes and not related to the degree of myopia [3]. However, conventional surgery could make the cornea undergo a pathological topographical change, from its initially prolate shape (Q , 0) with a steeper central area and flat peripheral area to an oblate shape (Q , 0) with a flat center and steep periphery [4-6]. Q value guided surgery aimed to minimize changes of the corneal anterior surface asphericity in order to reduce the spherical aberration, which impacts mostly on visual quality.. Most of previous papers about Q value guided ablation were focused on short or medium-term study, correcting low myopia or medium myopia, or comparing aspheric and conventional spheric ablation. Then what about correcting high myopic astigmatism? How the parameters of the anterior corneal surface changed following Q value guided LASIK and LASEK?In the present study, Q value guided LASIK and LASEK showed good efficacy, safety, and ...
The anterior surface of the scapula, next to the ribs The scapula is flat and concave on its anterior surface [facies costalis] (fig. 1) so as to fit the convexity of the ribs and while being fixed over them to be moveable as required, as well as to suit it to the muscle [m. subscapularis] (G in the 7th table of muscles, H in the 8th) which fills the entire anterior surface of the scapula and rotates the humerus inside and forward. This concave surface of the scapula is indeed smooth, but it is not even in all places; for next to its lower surface it puts forth certain tubercles (M, M, M in fig. 1) that stand out slightly as oblique lines 49 which make what amount to depressions, as if the ribs of the thorax on which this side of the scapula rests had been pressed into the scapula over time, and the scapula itself had taken on their outline by giving way. For these depressions and prominences appear more in the old than in children and youths, in whom everything protrudes and grows out less ...
Looking for online definition of posterior surface of elbow in the Medical Dictionary? posterior surface of elbow explanation free. What is posterior surface of elbow? Meaning of posterior surface of elbow medical term. What does posterior surface of elbow mean?
A retrospective analysis was performed on 504 virgin eyes assessed for laser vision correction measured between June 2009 and August 2011 using the Humphrey® ATLAS™ 9000. Corneal power at 100 points on 22 rings and Zernike coefficients from simulated corneal wavefront was obtained using the Export for research function. Simulated keratometry, manual keratometry, corneal wavefront, paraxial curvature matching and a new parameter known as CorT was calculated using the summated vector mean of topographic rings with adequate data and then compared for accuracy to the manifest refraction cylinder using the ocular residual astigmatism magnitude (ORA) and its variability (ORAsd ...
The first of its kind, Irregular Astigmatism: Diagnosis and Treatment synthesizes our knowledge and understanding of irregular astigmatism and addresses state-of-the-art technology in management and treatment. Dr. Ming Wang, assisted by Dr. Tracy Swartz, has led a team of internationally known experts in the field to produce this innovative, comprehensive, and logically presented text, which includes more than 300 illustrations to supplement the information provided ...
The sulfate ion internal optic modes in monoclinic $Li_{2}SO_{4} \cdot H_{2}O$ are studied using the molecular dipole model. The polarization direction of the B symmetry phonons lies in the a-c plane; however a unique direction is not given by symmetry considerations. An analysis of polarized near-normal incidence infrared reflection data complemented by Raman data suffices to uniquely determine the polarization of the phonon. In these systems a given A symmetry phonon is shown to be paired with a particular B symmetry phonon, that is, both phonons originate in the same site group internal mode. All site group modes here are of A symmetry. The correct pairing assignments for several internal modes are discussed ...
A 28-year-old healthy woman underwent implantation of a posterior chamber, phakic, toric implantable Collamer lens (ICL; STAAR Surgical, Nidau, Switzerland) in both eyes for correction of bilateral high myopia with astigmatism. Preoperatively, best-corrected visual acuity was 20/30 in the right eye with a refraction of −14.50 −3.50 × 15 and 20/20 in the left eye with a refraction of −12.50 −2.75 × 160. Slit-lamp examination of the anterior segment was unremarkable. Both pupils were light-reactive and isocoric, with 5 mm diameters under scotopic illumination. Fundus examination showed myopic changes, with no evidence of retinal tear bilaterally. On applanation tonometry, intraocular pressure (IOP) was 14 mm Hg in each eye. The preoperative corneal topography using Pentacam (Oculus Optikgeräte GmbH, Wetzlar, Germany) revealed bilateral regular astigmatism, with no specific findings identified on the anterior or posterior elevation maps. The central corneal thicknesses were 564 μm in ...
The mean Kmax value of the KeraVio-treated eyes decreased by 0.81 D at 6 months, although the value had increased by 6.03 D in the year before baseline. Thus, our study demonstrates that KeraVio has a beneficial effect on corneal topography in patients with corneal ectasia over the course of 6 months. Kmax, believed to be an important indicator of CXL success, decreased significantly after the procedure. Previous studies reported a reduction of 1-2 D in the mean Kmax of treated keratoconic eyes at 1 year.15 27 Ferdi et al 28 reported a systematic review and meta-analysis of keratoconus natural history data, including 11 529 eyes from 41 publications. Their meta-analysis of Kmax demonstrated a significant increase of 0.7 D at 12 months. Although no untreated control group was included in this pilot study, we believe that the efficacy of KeraVio was demonstrated by the stabilisation of progressive corneal disorder. In our study, the Kmax decreased by 2.0 D or more in four eyes (20%) and increased ...
Nationally recognized experts in managing keratoconus and pellucid marginal degeneration. We have extensive keratoconus contact lens experience.
The Pentacam is a high-resolution rotating Scheimpflug camera and slit illumination system that enables precise and reliable imaging and analysis of the anterior segment structures of the eye such as the cornea, iris and lens. Images only take 2 seconds to acquire, and do not require any contact with the eye. A 3-dimensional virtual model of the anterior segment is then constructed, and data points are used to calculate corneal topography and elevation on the front and back surface, total corneal power as well as anterior chamber depth and volume amongst other parameters. There are many additional features available on this machine that aid the diagnosis and management of anterior segment diseases such as keratoconus, and assist in pre-operative planning for cataract, corneal and refractive surgery. This is especially helpful for patients who have previously had laser vision correction, and enables detailed analysis of different parameters to optimize post-operative outcomes for patients.. ...
For those who want the flexibility of wearing contacts, Visionary offers the full range of options. Contact lenses technology has grown substantially in the last decade and our doctors have kept on the leading edge of these advances, enabling them to offer this flexibility to more patients than ever.. Specialty lenses are available for a variety of eye conditions including bifocals, astigmatism, and dry eyes. We regularly fit medically necessary contact lenses for patients with corneal conditions like keratoconus and pellucid marginal degeneration.. Your doctor will choose the lens that best meets your needs. We offer most of the major brands as well as lenses from small specialty labs. Instruction is provided on the proper lens care for first-time wearers.. ...
Keratoconus is a non-inflammatory, progressive thinning process of the cornea. It is a relatively common disorder of unknown etiology that can involve each layer of the cornea and often leads to high myopia and astigmatism. Computer- assisted corneal topography devices are valuable diagnostic tools for the diagnosis of subclinical keratoconus and for tracking the progression of the disease. The traditional conservative management of keratoconus begins with spectacle correction and contact
As part of our commitment to innovation, we offer specialty contact lenses for even for the most unique of eyes. We provide patients with corneal diseases such as keratoconus, pellucid marginal degeneration, etc. with customized scleral lenses that allow them to see better than glasses.
Corneal pachymetry is the process of measuring the thickness of the cornea. A pachymeter is a medical device used to measure the thickness of the eyes cornea. It is used to perform corneal pachymetry prior to refractive surgery, for Keratoconus screening, LRI surgery and is useful in screening for patients suspected of developing glaucoma among other uses. It can be done using either ultrasonic or optical methods . The contact methods, such as ultrasound and optical such as confocal microscopy (CONFOSCAN), or noncontact methods such as optical biometry with a single Scheimpflug camera (such as SIRIUS or PENTACAM), or a Dual Scheimpflug camera (such as GALILEI), or Optical Coherence Tomography (OCT, such as Visante) and online Optical Coherence Pachymetry (OCP, such as ORBSCAN). Corneal Pachymetry is essential prior to a refractive surgery procedure for ensuring sufficient corneal thickness to prevent abnormal bulging of the cornea, a side effect known as ectasia. The instrument used for this ...
Purpose: The aim was to assess the visual impact of ocular wavefront aberrations, corneal thickness, and corneal light scatter prospectively after performing a Descemet stripping automated endothelial keratoplasty (DSAEK) in humans. Methods: Data were obtained prospectively from 20 eyes preoperatively and at 1, 3, 6, and 12 months post-DSAEK. At each visit, the best spectacle-corrected visual acuity and visual acuity with glare (brightness acuity testing) were recorded, and ocular wavefront measurements and corneal optical coherence tomography (OCT) were performed. The magnitude and the sign of individual Zernike terms [higher-order aberrations (HOAs)] were determined. Epithelial, host stromal, donor stromal, and total corneal thicknesses were quantified. The brightness and intensity profiles of OCT images were generated to quantify light scatter in the whole cornea, subepithelial region, anterior and posterior host stroma, interface, and donor stroma. Results: The mean best spectacle-corrected visual
If left untreated, the cornea may thin to the point where a hole develops in the thinnest part. There is a risk of rejection after a cornea transplant, but the risk is much lower than with other organ transplants. You should not have laser vision correction (such as LASIK) if you have any degree of keratoconus. Corneal topography is done beforehand to rule out people with this condition. In rare cases, other laser vision correction procedures, such as PRK, may be safe for people with mild keratoconus. This may be more possible in people who have had corneal collagen cross-linking. ...
The use of a keratometric index to estimate total corneal power calculation is imprecise, especially in corneas with keratoconus or after myopic laser refractive surgery. The errors can be reduced by using an adjusted keratometric index, consisting of a variable keratometric index that depends on the radius of the anterior corneal surface. ...
In this study, we evaluated a large cohort of patients to identify the indications for and outcomes of corneal ring implantation. This is one of the first studies to report these parameters and to correlate them with the social and economic aspects of individuals living in Brazil.. Keratoconus was the most commonly reported corneal pathology. The results described in this study are consistent with those reported in the literature and confirm that keratoconus is the most common ectatic pathology 1,2.. Krachmer et al. suggested that patients without central corneal scars who have mild to moderate disease and who cannot tolerate contact lenses are the best candidates for intrastromal corneal implantation 20.. Intracorneal rings were initially proposed to correct ametropia 21-23 and were thereafter successfully used to treat mild to moderate keratoconus 3,24,25. They are also currently used to treat severe keratoconus 25-28, other types of corneal ectasia 29 and irregular astigmatisms 13.. However, ...
Human Anatomy: Sternum Anatomy The Anterior Surface Is Where The Anterior Costoxiphoid Ligament And A Part Of Rectus Abdominis Are ...
Purpose: Diabetic corneas have ultrastructural changes that can lead to dry eye, abnormal healing after trauma. The literature is sparse on the topic of Asian diabetics corneas with good Va and automated refractive keratometry readings. At our retina clinic in California, we retrospectively evaluated the keratometry readings of corneas of Diabetic patients in an Asian population. Are there external refractive or superficial keratometry differences in Asian Diabetic vs Asian Control eyes?. Methods: Corneal topography was performed using Topcon KR-8000PA Auto Kerato- Refractometer (Oakland, NJ) on patients as part of the refractive screening prior to dilation for evaluation of diabetic retinopathy ...
Indeed, discriminatively galvus costo many patients have resisted previous exhortations to withdraw and are now only emerging, often reluctantly (Edwards, Cantopher & Olivieri, 1990), as GPs review their prescription practices! Titrate dosage based on clinical response and drug tolerance up to a maximum of 3600 mg/day PO, silagra buy cipla given in divided doses. These were the words that used to run around my mind, el torero online casino echtgeld before I left my corporate job four years ago! If closely tugain foam 10 price you would like more information, talk with your healthcare provider? Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance! A corneal topographer is a machine that projects a disc of lights onto the cornea! 238 (1972), el torero online casino echtgeld retains the death penalty for six categories of crime: murder, [n4] kidnaping for ransom or where [p163] the victim is harmed, armed robbery, [n5] rape, treason, and aircraft ...
Ophtalmic measurment instruments. Corneal topographers. Exophthalmometers. Keratoscopes. Ophthalmic colorimeters. Ophthalmic distometers. Ophthalmic perimeters.
We report a new association in our two cases. Such concurrence of early keratoconus and the syndrome raises the possibility of a genetic linkage, although a chance association cannot be excluded.. On one hand, either chromosomal rearrangements such as chromosome 7, 11 translocation or genetically determined syndromes such as this syndrome should be considered in cases where keratoconus is present during childhood.6 That may explain the early presentation of keratoconus in our cases. An additional factor is that keratoconus tends to be more prevalent and diagnosed at a younger age in Asians than in white people.3. On the other hand, familial keratoconus in our cases cannot be excluded because of the presence of keratoconus in a single relative and parental consanguinity. Positive family history has been reported in 6% to 10% of keratoconus cases and is suggested to be caused by autosomal dominant inheritance with incomplete penetrance.1,2,3. To the best of our knowledge, this is the first report ...
Hi,. I have keratoconus in both eyes past 4+ years. I have already done corneal cross linking for my left eye in 2016 and December 2019 doctor said that i have to do cross linking for both eyes.. After January,2020 i have done this treatment. May i know what is the situation of my eyes?. I have attached my corneal topography testing result.. Please contact me as soon as possible.. Thanks ...
The Pentacam Comprehensive Eye Scanner is a rotating camera that photographs both the anterior (front) and posterior (back) surfaces and other areas of the cornea (the front part of the eye). The Pentacam Scanners main advantage is that it provides more precise measurements of the central cornea than any other ocular measurement instrument currently available.. The Pentacam has improved the ability of eye physicians to diagnose ocular conditions, especially the eye condition known as keratoconus, more accurately than in the past.. The Pentacam and Keratoconus. Keratoconus (also known as corneal ectasia) is a condition where the cornea gradually becomes thinner and steeper, causing it to bulge forward from the pressure of internal fluids inside the eye. Each case of keratoconus case is unique, so treatment is also highly customized.. Individuals with keratoconus may see multiple images and experience nearsightedness and astigmatism. Some experience mild symptoms and are unaware of having a ...
If you have had Intacs® and are interested in further options to improve your vision, Dr. Brian, who is one of the most experienced Keratoconus doctors, routinely evaluates patients who have had Intacs® placed elsewhere. Further vision improvement can be an option through 1) Intacs® adjustments for different size, 2) removal (also known as explant) of the upper Intac segment, 3) Holcomb C3-R®, also called corneal crosslinking, to stabilize Keratoconus, and 4) CK (conductive keratoplasty) to improve astigmatism.. If you are considering having Intacs® done by a surgeon other than Dr. Brian, here are some compelling reasons you want to re-think that and have Dr. Brian perform your Intacs®.. ...
Bausch + Lomb, an American company founded in Rochester, New York, is one of the worlds largest suppliers of eye health products, including contact lenses, lens care products, medicines and implants for eye diseases. The company was founded in 1853 by an optician, John Jacob Bausch, and a financier, Henry Lomb. Its Ray-Ban brand of sunglasses was sold in 1999 to the Italian Luxottica Group. Bausch + Lomb was a public company listed on the NYSE until it was acquired by the private equity firm Warburg Pincus PLC in 2007. In May 2013, Valeant Pharmaceuticals agreed to buy Bausch + Lomb from Warburg Pincus LLC for $8.57 billion in cash. The deal, which was approved by share holders, included $4.2 billion earmarked to pay down Bausch + Lomb debt, and closed on August 5, 2013. Today, the company is headquartered in Bridgewater, New Jersey, and employs about 13,000 people in 36 countries.Lentilles de contact
According to the National Keratoconus Foundation (NKCF), keratoconus (KC) is estimated to occur in 1 out of every 2,000 persons in the general population. Keratoconus is a disorder that causes thinning of the cornea resulting in a cone-shaped bulge that distorts vision. Symptoms include visual blurring and distortion along with increased light sensitivity. It can progress to a degree that severely impacts a patients quality of life, limiting the ability to perform everyday tasks such as driving, reading, or watching TV. BostonSight® PROSE treatment has helped many keratoconus patients regain visual function and acuity and successfully return to the activities they enjoyed prior to their diagnosis. Although the exact cause of KC is unknown, it is thought that genetics, the environment, and the endocrine system all contribute to the development of KC. An online article published in the journal Nature Genetics offers an overview of recent genetic findings on the causation of keratoconus. A large ...
A pterygium is an elevated, superficial, external ocular mass that usually forms over the perilimbal conjunctiva and extends onto the corneal surface. Pterygia can vary from small, atrophic quiescent lesions to large, aggressive, rapidly growing fibrovascular lesions that can distort the corneal topography, and, in advanced cases, they can ob...
Placido Domingo, who was hospitalized last week in Madrid, has been released and is in high spirits. The 72-year-old opera star suffered a scare when he was diagnosed with a pulmonary embolism resulting from a deep venous thrombosis (basically a blocked blood vessel, which can result from a long...
Spanish opera tenor Placido Domingo has been admitted to a Madrid hospital after suffering a pulmonary embolism - a blood clot in his lung, his U.S. publicist said on Tuesday.
Simulating atmospheric turbulence is an essential task for evaluating turbulence mitigation algorithms and training learning-based methods. Advanced numerical simulators for atmospheric turbulence are available, but they require evaluating wave propagation which is computationally expensive. In this paper, we present a propagation-free method for simulating imaging through turbulence. The key idea behind our work is a new method to draw inter-modal and spatially correlated Zernike coefficients. By establishing the equivalence between the angle-of-arrival correlation by Basu, McCrae and Fiorino (2015) and the multi-aperture correlation by Chanan (1992), we show that the Zernike coefficients can be drawn according to a covariance matrix defining the correlations. We propose fast and scalable sampling strategies to draw these samples. The new method allows us to compress the wave propagation problem into a sampling problem, hence making the new simulator significantly faster than existing ones. ...
The situation and form of the patella A certain round bone [patella] (all of figs. 1, 2 and C on the skeletons) is situated in front of the anterior surface of the knee joint, not unlike a small shield. 5 On its posterior surface [facies articularis] where it faces the femur, it is seen for the most part covered with smooth, slippery cartilage [cartilago articularis], its swelling and depressions elegantly matching the anterior surface [facies patellaris] (H in fig. 2, ch. 30) of the lower heads [condylus medialis, condylus lateralis] of the femur. Along its longitude, it projects with a wide and moderately protruding eminence [eminentia recta] (A, B in fig. 2) which enters the wide depression [facies patellaris] carved in the anterior of the femoral heads. On each side (C, D in fig. 2) of this eminence there is a depression [facet] that receives the projecting surfaces of the femoral heads, which are coated with cartilage [c. articularis]. But as the outer head [condylus lateralis] of the femur ...
This study will determine the efficacy of collagen cross linking for progressive keratoconus and ectasia after lasik. It will try and determine which is a more effective treatment: collagen cross linking alone or collagen cross linking combined with Intacs, a treatment which has already been proven to be effective in decreasing corneal curvature in patients with keratoconus ...
Over 1,200 keratoconus patients were enrolled at 15 participating clinics across the United States, examined at enrollment (between May 1995 and June 1996) and annually through 8 years of follow-up (the last 8-year follow-up was completed in August 2004 ...
CXL is a unique treatment because it is noninvasive and targets the root of the problem which is the weakened cornea in keratoconus. CXL significantly increases the number of collagen bonds between the corneal layers, in effect returning the cornea to a more stable state. In contrast to other procedures like intrastromal ring segments or laser surgery, only CXL offers the potential to target the underlying cause and thus offer long-term benefits for those suffer from keratoconus.. More interestingly, CXL can be a part of a process in the management of keratoconus patients. It can be combined with Intacs before or after the procedure, and fine tuned with surface laser procedures. ...
QUALITATIVE ANALYSIS. Table 3 describes all qualitative analysis results. There was a statistically significant tendency to make correct matches as evaluator age increased. The percent correct matches were significantly lower in the CH evaluator group compared with each of the other groups. The comparison between AD and RS was also significantly different. The percent correct matches of AD vs. OP and OP vs. RS were both not significantly different. The percent correct matches for only aspheric and established keratoconus topographies or KS topographies alone was also analyzed. When only aspheric and keratoconus topographies were evaluated, the comparisons did not change their pattern, except for OP vs. RS, which was statistically significant. When the analysis included only KS topographies, the percent correct matches decreased in every evaluator group and the CH group was no longer statistically different from AD group, but the difference remained when comparing CH with OP and RS groups. ...
Intacs for keratoconus Yaron S. Rabinowitz Purpose of review The use of Intacs as a therapeutic modality in contact lens intolerant patients with mild to moderate keratoconus is increasingly gaining acceptance
Corneal pachymetric topography. Ophthalmology 101:432-438, 1994. Reinstein DZ, Silverman RH, Raevsky T, Simoni GJ, Lloyd HO, ... Arc-scanning very high-frequency ultrasound for 3-D pachymetric mapping of the corneal epithelium and stroma in laser in situ ... This system allowed demonstration of the importance of arc-scanning for corneal analysis and led to the subsequent development ... Epithelial and corneal thickness measurements by high-frequency ultrasound digital signal processing, Ophthalmology, 101: 140- ...
Corneal topography (April 4, 2006). *Charles Schepens (April 9, 2006). *Iridodialysis (October 15, 2006) ... Copyedit : Fungal keratitis, Blepharochalasis, Phthiriasis, Eye trauma, Optic neuropathy, Keratoglobus, Corneal ulcer, Cone ... Cleanup : Conjunctivitis,Conjunctivochalasis, Corneal dystrophy, Eye surgery, Oculoplastics, Rubeosis iridis, Conjunctival ... concretion, Iridoplegia, Corneal ulcer, Corneal abrasion, Ocular tilt reaction. * ...
Preliminary investigation of the corneal topography. The test maps a patient's cornea for raised areas and surface ... a small amount of tissue from the corneal stroma at the front of the eye, just under the corneal epithelium. The outer layer of ... "CORNEAL REFRACTIVE SURGERY (ICD9 V802A/V802B)" (PDF). January 2006. Retrieved August 16, 2013.. Archive index at the Wayback ... Granular corneal dystrophy type II. Possible complications[edit]. Some complications that can be temporary or permanent include ...
The gold standard diagnostic test for PMD is corneal topography. However, it may not be as specific as corneal pachymetry, ... Pellucid marginal degeneration is diagnosed by corneal topography. Corneal pachymetry may be useful in confirming the diagnosis ... if corneal topography is used for diagnosis, it should be in conjunction with clinical findings of peripheral, inferior corneal ... Corneal topography may show a "crab claw-like" appearance, a finding that is seen in both keratoconus and in pellucid marginal ...
Kiely PM, Carney LG, Smith G (October 1983). "Menstrual cycle variations of corneal topography and thickness" (PDF). American ... Leach NE, Wallis NE, Lothringer LL, Olson JA (May 1971). "Corneal hydration changes during the normal menstrual cycle--a ...
... anterior corneal) astigmatism is measured through the use of techniques such as keratometry and corneal topography. One method ... Corneal topography may also be used to obtain a more accurate representation of the cornea's shape. An autorefractor or ... Corneal Topography and Imaging at eMedicine Graff, T (1962). "Control of the determination of astigmatism with the Jackson ... "Classification of normal corneal topography based on computer-assisted videokeratography". Archives of Ophthalmology. 108 (7): ...
"Corneal topography and Schirmer testing in eyes with the Hudson,-,Stahli line". Eye. 16 (3): 267-70. doi:10.1038/sj.eye.6700028 ... It lies in the corneal epithelium. Usually it has about 0.5 mm in thickness and is 1-2 mm long. It is generally horizontal, ... Fleischer ring - corneal iron depositions in keratoconus Ophthalmology Myron Yanoff, Jay S. Duker Edition 3, illustrated ...
Is the future of refractive surgery based on corneal topography or wavefront? "Ocular Surgery News". August 1, 2000, page 26. ... Both the depth of the corneal incisions and the degree of central corneal flattening correlated with the laser energy applied. ... Those with Fuchs' corneal endothelial dystrophy, corneal epithelial basement membrane dystrophy, retinal tears, autoimmune ... or corneal topography machine, to measure their surface contour. Using low-power lasers, a topographer creates a topographic ...
Corneal topography indices after corneal collagen crosslinking for keratoconus and corneal ectasia One-year results. J Cat ... Refractive Corneal Surg. 1994;10:571-574. Hersh PS, Schwartz-Goldstein B. Summit PRK Topography Study Group. Corneal topography ... "Corneal topography indices after corneal collagen crosslinking for keratoconus and corneal ectasia: One-year results". Journal ... Summit PRK Topography Study Group. Corneal topography of phase III excimer laser photorefractive keratectomy: Optical zone ...
The corneal thickness from mild (> 506 μm) to advanced (< 446 μm). Increasing use of corneal topography has led to a decline in ... A more definitive diagnosis can be obtained using corneal topography, in which an automated instrument projects the illuminated ... The corneal transplant surgeon trephines a lenticule of corneal tissue and then grafts the donor cornea to the existing eye ... Maguire LJ, Bourne WM (August 1989). "Corneal topography of early keratoconus". American Journal of Ophthalmology. 108 (2): 107 ...
"Evaluation of corneal thickness and topography in normal eyes using the Orbscan corneal topography system". Br J Ophthalmol. 83 ...
"Evaluation of corneal thickness and topography in normal eyes using the Orbscan corneal topography system". The British Journal ...
Corneal topography may also be used to obtain a more accurate representation of the cornea's shape. An autorefractor or ... It is typically characterized by an aspherical, non-figure of revolution cornea in which the corneal profile slope and ...
The specific application of UVA for each patient takes into account the refractive error and corneal topography. The major ... PiXL is a high-fluence corneal collagen cross-linking administered in a customizable pattern and intensity in order to flatten ... or steepen the cornea through corneal strengthening. ...
Corneal and Retinal Topography: computerized tests that maps the surface of the retina, or the curvature of the cornea. ...
Corneal topography and pachymetry are used to screen for abnormal corneas. Furthermore, some people's eye shape may not permit ... Customized Transepithelial No-touch (C-TEN) is an innovative strategy for corneal surgery that avoids any corneal manipulation ... such as corneal topography. While refractive surgery is becoming more affordable and safe, it may not be recommended for ... It involves cutting a flap in the cornea and pulling it back to expose the corneal bed, then using an excimer laser to ablate ...
Corneal topography is considered a more quantitative test, and for purposes of aligning a toric IOL, most surgeons use a ... which is calculated by the internal programming of the corneal topography machine, to determine the astigmatic meridian on the ... including manifest refraction or corneal topography. Manifest refraction is the familiar test where the eye doctor rotates ... It is believed to have a lesser effect on corneal endothelium. The main complication with this type is their tendency to cause ...
He has also done extensive research in corneal crosslinking and topography-guided PRK for keratoconus, procedures he introduced ... Applications of Corneal Crosslinking, Refractive Eyecare for Ophthalmologists, Ethis Publishing, March 2010. http://www. ...
... have demonstrated the ability of OCT systems to depict pathology within the cornea as well as disorders of corneal topography. ... Direct corneal elevation measurements using multiple delay en face optical coherence tomography. J Biomed Opt. 2008 Sep-Oct;13( ... High-speed optical coherence tomography of corneal opacities. Ophthalmology. 2007 Jul;114(7):1278-85. Plesea et al. ...
As the inflammation is reduced, the stroma appears to be thin and the corneal topography changes to show an area of depression ... The corneal response to the treatment appears to be as expected until the four-day mark where the corneal inflammation and ... It could also show corneal edema which leads to thickening the corneal to 30%. Extensive conjunctival injection, which is an ... corneal abrasion and infectious corneal ulcer. Now, in order to diagnosis Christmas eye, it's essential to take a look at the ...
A modern development of the concept is found in corneal topography, in which analysis of the reflected image is passed to a ... The automated instrument can produce colour-coded contour maps of the eye's topography or even three-dimensional visualisations ... If the patient is suffering from astigmatism or from a corneal dystrophy, the rings will be distorted. ...
... however corneal topography is a practical test (technique) as the condition worsens. Pterygium should be differentiated from ... "Facts About the Cornea and Corneal Disease , National Eye Institute". The National Eye Institute (NEI). May 2016. Archived from ... Other conditions that can look similar include a pinguecula, tumor, or Terrien's marginal corneal degeneration. Prevention may ... as it invades the cornea with the potential of obscuring the optical center of the cornea and inducing astigmatism and corneal ...
Central corneal power can be measured by keratometry or corneal topography. Corneal radius of curvature relates to corneal ... which uses the pre-LASIK corneal power for the calculation of the ELP, and the post-LASIK corneal power for the calculation of ... corneal topographers) cannot obtain accurate measurements in eyes that have undergone corneal refractive surgery. Most manual ... The central corneal power is the second important factor in the calculation formula. To simplify the calculation, the cornea is ...
Rabinowitz, YS; McDonnell, PJ (1989). "Computer-assisted corneal topography in keratoconus". Refractive & Corneal Surgery. 5 (6 ... custom topography-guided transepithelial PRK combined with corneal collagen cross-linking, or corneal transplant. When cross- ... Abnormal corneal topography compromises of keratoconus, pellucid marginal degeneration, or forme fruste keratoconus with an I-S ... "Post-LASIK ectasia treated with intrastromal corneal ring segments and corneal crosslinking". Digital Journal of Ophthalmology ...
It is also the principle used in corneal pachymetry, the mapping of corneal topography, done prior to refractive eye surgery ...
However, it was not until computerized corneal topography became available during the 1990s that it became possible to apply ... In June 2002, the FDA granted approval for overnight wear of a type of corneal reshaping called "Corneal Refractive Therapy" ( ... 2001 Aug;108(8):1389-99 Macsai, M.D., Marian S. (January 2005). "Corneal Ulcers in Two Children Wearing Paragon Corneal ... Each patient presented with a bacterial corneal ulcer after wearing CRT contact lenses for less than 6 months. In the first ...
... tomography Elastography Electrical impedance tomography Optoacoustic imaging Ophthalmology A-scan B-scan Corneal topography ...
... corneal topography MeSH E01.370.380.225 - electroretinography MeSH E01.370.380.235 - eye movements MeSH E01.370.380.235.280 - ... moire topography MeSH E01.370.350.600.631 - photography, dental MeSH E01.370.350.600.635 - photomicrography MeSH E01.370. ...
Positive relative accommodation Vergence system Optokinetic system Amsler grid Gonioscopy Corneal topography Corneal pachymetry ... Fluorescein staining before slit lamp examination may reveal corneal abrasions or herpes simplex infection. The binocular slit- ...
Corneal topography. *Optical coherence tomography. *Electrodiagnosis: Electrooculography. *Electroretinography. * ...
Corneal topography. *Optical coherence tomography. *Electrodiagnosis: Electrooculography. *Electroretinography. * ... Keratomileusis, from Greek κέρας (kéras: horn) and σμίλευσις (smileusis: carving),[1] or corneal reshaping, is the surgical ... Before the advent of the excimer laser, keratomileusis was performed using a cryolathe, which froze thin flaps of corneal ...
Corneal topography. *Optical coherence tomography. *Electrodiagnosis: Electrooculography. *Electroretinography. * ...
Corneal topography. *Optical coherence tomography. *Electrodiagnosis: Electrooculography. *Electroretinography. * ... Corneal collagen cross-linking[edit]. Corneal collagen cross-linking may delay or eliminate the need for corneal ... Corneal transplantation, also known as corneal grafting, is a surgical procedure where a damaged or diseased cornea is replaced ... Intrastromal corneal ring segments[edit]. In corneal disorders where vision correction is not possible by using contact lenses ...
Corneal topography. *Optical coherence tomography. *Scanning laser ophthalmoscopy. Some of these techniques[example needed] are ...
Corneal topography. *Eye disease. *List of keratins expressed in the human integumentary system ...
Corneal topography. *Optical coherence tomography. *Electrodiagnosis: Electrooculography. *Electroretinography. * ...
The Ophthalmological Hospital[5] is the hospital that performs more transplants and corneal uptake in Brazil. It was honored at ... with higher relief and the rocks of the Parana Sedimentary Basin and gently rolling topography with lower altitudes. The ...
Corneal topography. *Cranial ultrasound. *CT Gastrography. *Current density imaging. D. *Depth kymography ...
... applications of corneal Crosslinking 1999 World's first wavefront-guided laser treatment on the human eye 2002 First topography ... His work and research interests include corneal surgery, especially refractive corneal surgery, surgery of the anterior segment ... He habilitated at the Free University of Berlin in 1987 with his scientific paper "Refractive corneal surgery" and was ... Eyes 1988 World's first Holimum YAG laser PRK thermokeratoplasty 1989 First clinical studies on PRK 1995 Invention of Corneal ...
... computerized corneal topography, endothelial microscopy, ultrasound pachymetry, b-scan sonography, keratometry and ... Corneal cross-linking with riboflavin (vitamin B2) and UV-A light is a surgical treatment for corneal ectasia such as ... "Corneal collagen crosslinking: A clinical update". Corneal Collagen Cross-Linking on National Keratoconus Foundation website. ... In this group, the most common side effects are haziness of the cornea, punctate keratitis, corneal striae, corneal epithelium ...
In 79% of these cases, sealers did not check the corneal reflex to ensure that the seals were dead prior to hooking or skinning ... There are also words referring to seasons, topography, place names, legends, and kinship relationships based on the seal. One ... of the sealers recorded on the four videotapes failed to palpate the skull or check the corneal reflex before proceeding to ... including checking for a corneal reflex and bleeding animals immediately after clubbing." In 2005, the World Wildlife Fund (WWF ...
"Fast Facts, Geography, Topography". navajobusiness.com. Retrieved 27 July 2017. Comerford, Kevin. "Checkerboard Reservation, ... Other symptoms include corneal anesthesia and scarring, acral mutilation, cerebral leukoencephalopathy, failure to thrive, and ...
"CXL, topography-guided, customized ablation Tx for keratoconus and post-LASIK". Archived from the original on 2016-03-10. " ... He performs complex corneal collagen and cross-linking (CXL) procedures for keratoconus patients, combined with excimer laser ... He went on to complete his post-doctoral fellowship training in corneal transplantation, cataract surgery and laser refractive ... In 2015, Wallerstein and Cohen launched a new laser vision procedure called Laser PresbyVision™, a corneal-based treatment ...
Sun XC, Bonanno JA (2003). "Identification and cloning of the Na/HCO(3-) cotransporter (NBC) in human corneal endothelium". Exp ... 2003). "Identification of membrane topography of the electrogenic sodium bicarbonate cotransporter pNBC1 by in vitro ...
Corneal pachymetry Corneal reflex Corneal tattooing Corneal topography Eye disease Keratometry List of keratins expressed in ... For corneal epithelial diseases such as Stevens Johnson Syndrome, persistent corneal ulcer etc., the autologous contralateral ( ... The most common corneal disorders are the following: Corneal abrasion - a medical condition involving the loss of the surface ... Corneal dystrophy - a condition in which one or more parts of the cornea lose their normal clarity due to a buildup of cloudy ...
While corneal topography relies on reflected light from the front (anterior) of the cornea, a technique called corneal ... Computerized corneal topography can be employed for diagnostics. It is, in fact, one of the exams the patients have to undergo ... Corneal Topography measuring and modifying the cornea - Schanzlin 1992, page 4-5 Gullstrand A (1909). "Procedure of rays in the ... Corneal topography, also known as photokeratoscopy or videokeratography, is a non-invasive medical imaging technique for ...
... this presentation helps identify and interpret corneal topographies in patients scheduled for cataract surgery and demonstr ... Led by a team of topography experts, ...
Other: Topography guided Excimer Laser treatment and Corneal Cross Linking Other: Corneal Cross Linking Phase 3 ... Other: Topography guided Excimer Laser treatment and Corneal Cross Linking A topography guided excimer laser treatment will be ... Patients will receive a standard corneal cross linking treatment. Other: Corneal Cross Linking A standard corneal cross linking ... Corneal Cross Linking and Topography Guided Excimer Laser Treatment. The safety and scientific validity of this study is the ...
... central corneal regularization) and corneal CXL induced by riboflavin-ultraviolet A.Results: After a mean 15 ± 6.5 (range 6-24 ... The combination of customized PRK and corneal CXL provided safe and effective results in the management of corneal ... and prophylactic corneal collagen crosslinking (CXL) for residual refractive error in a group of patients who had previously ... 12.4 months since ELLK they underwent combined simultaneous corneal regularization treatment with topographically guided ...
Home Clinical Education Webinars Corneal Tomography and Topography for the Cataract and Refractive Surgeon ... this webinar will address how the cataract and refractive surgeon can best optimize topography and tomography to achieve better ...
Forty-three eyes of 22 patients who underwent topography-guided FS-LASIK for myopic correction were included. The ... To observe the epithelial remodeling over a 9-mm diameter cornea induced by topography-guided femtosecond laser-assisted in ... Stromal surface topography-guided custom ablation as a repair tool for corneal irregular astigmatism. J Refract Surg. 2015;31: ... Stromal surface topography-guided custom ablation as a repair tool for corneal irregular astigmatism. J Refract Surg. 2015;31: ...
Findings from anecdotal case reports are supported by clinical studies to highlight the relevance of advances in corneal ... including Placido disk-based corneal topography, Scheimpflug corneal tomography, ocular wavefront analysis, and corneal ... "Corneal topography does augment sensitivity to detect keratoconus in many cases with normal biomicroscopy and normal corrected ... Corneal tomography or topography: When to make the clinical decision. @media screen and (max-width: 468px) { .video-detail .doc ...
Combined topography-guided PRK and corneal collagen cross-linking are a safe and effective option in the management of mild and ... nonrandomized interventional study including 20 eyes of 14 patients with grade 1-2 keratoconus that underwent topography-guided ... i,Purpose.,/i, To evaluate effectiveness of simultaneous topography-guided photorefractive keratectomy and corneal collagen ... The device collects corneal topography, ocular wavefront, autorefraction, and pupillometric data. The topography is Placido- ...
Find any required new, refurbished or used Corneal Topography System Equipment or device. ... used Corneal Topography System Equipment for sale or auction. ... Corneal Topography System may also be referred to as : ... Corneal , Keratography System, Video , Computer Assisted Corneal Topography System , Computed Corneal Topography System ... Tips for buying Corneal Topography System. *Facilities should consider several parameters prior to making the purchase, ...
Su Ah Kim, Kui Dong Kang, Ji Sun Paik, Su Kyung Jung, Suk-Woo Yang; Effect of Orbital Decompression on Corneal Topography in ... Corneal topography (Orbscan II), Hertel exophthalmometry, and intraocular pressure were measured at 1 month before and 3 months ... Corneal topographic parameters analyzed were the total astigmatism(TA), steep axis(SA), central corneal thickness(CCT), and ... Effect of Orbital Decompression on Corneal Topography in patients with thyroid ophthalmopathy ...
Differentiating Keratoconus and Corneal Warpage by Analyzing Focal Change Patterns in Corneal Topography, Pachymetry, and ... Lim L Wei RH Chan WK Tan DT . Evaluation of keratoconus in Asians: role of Orbscan II and Tomey TMS-2 corneal topography. Am J ... Computer-assisted corneal topography devices have become indispensable for diagnosing subclinical/clinical KC and for ... Progression of Keratoconus by Longitudinal Assessment with Corneal Topography You will receive an email whenever this article ...
Purpose To assess the refractive improvements and the corneal endothelial safety of an individualised topography-guided regimen ... Refractive improvements and safety with topography-guided corneal crosslinking for keratoconus: 1-year results ... Refractive improvements and safety with topography-guided corneal crosslinking for keratoconus: 1-year results ... corneal collagen crosslinking (CXL); n=25). Visual acuity, refraction, keratometry (K1, K2 and Kmax) and corneal endothelial ...
Aladdin HW 3.0-Biometry, Corneal Topography and Premium IOLs by Ike Ahmed, MD ... shares his viewpoint on accurate biometric values and a comprehensive analysis of the corneal surface. ...
Learn about corneal topography, an important component of a contact lens examination which keeps track of changes within the ... However, corneal topography has revolutionized corneal shape analysis. Instead of just measuring two points, a corneal ... During my annual contact lens exam, my doctor charges an extra fee for corneal topography. What is corneal topography? ... What Is Corneal Topography? Print By Troy Bedinghaus, OD , Medically reviewed by a board-certified physician ...
... subepithelial corneal power and topography for disease diagnosis ... Methods and systems to measure corneal epithelial thickness and ... subepithelial corneal power and topography for disease diagnosis uspto.gov May 23 2017. Ophthalmology , Patents ... subepitheila corneal power and topography. The systems and methods disclosed herein are non-invasive, non-contact and automated ... This invention discloses methods and systems for measuring corneal epithelial thickness and power, stromal thickness, ...
... may be reasonable and medically necessary in the following clinical situations. * corneal ulcers ... Corneal topography is performed with a non-contact instrument called a corneal topographer. These instruments work by ... Important clinical functions of corneal topography include the following. * earlier and more accurate diagnosis of corneal ... Corneal Topography. Many eye diseases affect the physical features and shape of the anterior surface of the cornea. These ...
Corneal topography is a process for mapping the surface curvature of the cornea, similar to making a contour map of land. The ... Corneal Topography?. Corneal topography is not a routine test. Rather, it is used in diagnosing certain types of problems, in ... Assisted Corneal. Topography. Corneal topography is a process for mapping the surface curvature of the cornea, similar to ... Corneal Topography. Work?. The corneal topographer is made up of a computer linked to a lighted bowl that contains a pattern of ...
Medmont E300 Corneal Topographer. View Video. The Medmont E300 Corneal Topographer gives accurate mapping of the corneal ... Coverage extends from a minimum ring diameter of 0.25mm to beyond 10mm, which is ideal for detailed assessment of corneal ... Using 32 concentric rings with 9,600 measurement points and 102,000 analyze points, the E300 provides detailed topography data ...
... , as the name might suggest, is an imaging technique used to map out the curvature of your cornea (the front ... Diagnosing and monitoring corneal conditions such as Keratoconus. *Investigation of astigmatism for contact lenses and before ...
Example of placido based corneal topography. This image depicts a large quantity of "with-the-rule" corneal astigmatism. The ... Example of placido based corneal topography. This image depicts a large quantity of "with-the-rule" corneal astigmatism. The ... Corneal topography. This test, completed by approximately 93% of surgeons performing refractive procedures, is used to assess ... Corneal scarring/haze (, 1-2%). *. Although LASEK may carry a decreased rate of corneal haze relative to PRK, it may still ...
Corneal Topography Testing. Duration: 30 seconds. A corneal topographer is a specialized computerized equipment that is used to ... Corneal Topography Testing. Corneal Topography Testing. David Mitchell, OD, discusses Corneal Topography Testing ...
Hans Lewis has a distinguished career working at the intersection of healthcare and technology for more than 13 years. He looks after the Partnership and Strategy for DocMode. Prior to the Creation of DocMode.org in 2009, Hans worked in the field of Healthcare Advertising as a Copywriter and followed up as a Sponsorship Head in Medical Events. In the initial years of DocMode, he was the Freelance contributing editor for TMCnet covering articles predominantly in Healthcare IT. He is a Tech autodidact and is also the project Head of the award-winning and patented clinical nutrition management app www.iNutrimon.com Graduated in Advertising, he has a Masters in Philosophy from Mumbai University. Yoga and Logic is his interest areas ...
The range of corneal topography measurement (D) in this study was from 32.8D to 46.3D. The mean corneal topography measurement ... The factors that influence a normal corneal topography are not well understood. Factors that may change the corneal curvature ... Therefore, the factors evaluated in this study were cornea topography changes by corneal topography measurement. ... Corneal topography changes following strabismus surgery. 1Universiti Sains Islam Malaysia. Purpose - to determine whether ...
The range of corneal topography measurement (D) in this study was from 32.8D to 46.3D. The mean corneal topography measurement ... The factors that influence a normal corneal topography are not well understood. Factors that may change the corneal curvature ... Therefore, the factors evaluated in this study were cornea topography changes by corneal topography measurement. ... The differences between corneal topography measurement was done using the repeated measure analyses. Results. A total of 17 ...
These data demonstrate that the PAR CTS is both highly accurate and reproducible in determining topography of spheres that ... The PAR Technology Corneal Topography System Refract Corneal Surg. Jan-Feb 1992;8(1):88-96. ... The PAR Technology Corneal Topography System (PAR CTS) is a prototype of a new computer-assisted corneal imaging device. The ... Conclusions: These data demonstrate that the PAR CTS is both highly accurate and reproducible in determining topography of ...
... a very strong lens responsible for as much as 75% of the eyes ... Computerized Corneal Topography The cornea functions as a very strong lens responsible for as much as 75% of the eyes focusing ... The computerized corneal topography measures this important surface giving us a color coded display containing detailed ... The greatest advantage of the computerized corneal topography is that it can detect conditions too subtle or invisible to even ...
Corneal Topography. Topographical map of the front surface of the eye shows the doctor how much and where your astigmatism lies ... Instead of ultrasound, this computer uses a mild beam of laser to measure the axial length and corneal measurements.This has ... The usual measurements are corneal, white to white,and axial length. These numbers are placed in two or more computer programs ...
Corneal topography is interpreted much like other topography maps. The cool shades of blue and green represent flatter areas of ... Corneal topography is used in the diagnosis and management of various corneal curvature abnormalities and diseases such as:. * ... The purpose of corneal topography is to produce a detailed description of the shape and power of the cornea. At Ezekiel Eyes we ... Corneal topography is a process for mapping the surface curvature of the cornea, similar to making a contour map of land. The ...
CORNEAL TOPOGRAPHY (SIRIUS). This examination serves to measure the front and back surface of the cornea. It can be used to ... since the measured value is influenced by the corneal thickness in most common methods. With the result of the corneal ... The corneal surface is individual for each person. The anterior and posterior surface of the cornea is measured topographically ... The endothelial camera is used to measure the number and size of cells on the inside of the cornea (corneal endothelium), which ...
The G4 Galilei corneal topographer includes easy-to-interpret reports for cataract and refractive surgery. Optional licenses ... Total Corneal Wavefront Report. Curvature Topography. Elevation Topography. Densitometry. Eye Metrics Report. IOL Calculation ... Corneal Topographer Reports for the Galilei G4. Refractive Software Package. Refractive Topographer Report. Asymmetry Report. ... Corneal Inlay Module. DICOM/EMR Connection. Remote Workstation. CSV Export for Clinical Studies ...
  • It is, in fact, one of the exams the patients have to undergo prior to the Cross-linking and the Mini Asymmetric Radial Keratotomy (M.A.R.K.). For example, the KISA% index (keratometry, I-S, skew percentage, astigmatism) is used to arrive at a diagnosis of keratoconus, to screen the suspect keratoconic patients and analyse the degree of corneal steepness changes in healthy relatives. (wikipedia.org)
  • The purpose of this paper is to report the results of using combined treatment of customized excimer laser-assisted photorefractive keratectomy (PRK) and prophylactic corneal collagen crosslinking (CXL) for residual refractive error in a group of patients who had previously undergone lamellar keratoplasty for keratoconus. (dovepress.com)
  • The combination of customized PRK and corneal CXL provided safe and effective results in the management of corneal regularization for refractive purposes after ELLK for keratoconus. (dovepress.com)
  • Dr. Ambrósio said that a classic question about tomography relates to whether it is a more sensitive modality than Placido disk-based topography to detect mild forms of keratoconus and screen for ectasia risk prior to refractive laser vision correction (LVC). (ophthalmologytimes.com)
  • Corneal topography does augment sensitivity to detect keratoconus in many cases with normal biomicroscopy and normal corrected visual acuity and is also efficient for identifying clinical keratoconus," he said. (ophthalmologytimes.com)
  • One such report described a case of unilateral ectasia identified in a patient who had been referred for treatment of keratoconus in his right eye.14 Unilaterality of the ectatic disease was confirmed by extensive diagnostic evaluation, including Placido disk-based corneal topography, Scheimpflug corneal tomography, ocular wavefront analysis, and corneal segmental tomography with epithelial thickness mapping by very high frequency digital ultrasound and spectral-domain OCT. (ophthalmologytimes.com)
  • To evaluate effectiveness of simultaneous topography-guided photorefractive keratectomy and corneal collagen cross-linking in mild and moderate keratoconus. (hindawi.com)
  • Prospective nonrandomized interventional study including 20 eyes of 14 patients with grade 1-2 keratoconus that underwent topography-guided PRK using a Custom Ablation Transition Zone (CATz) profile with 0.02% MMC application immediately followed by standard 3 mw/cm 2 UVA collagen cross-linking. (hindawi.com)
  • Combined topography-guided PRK and corneal collagen cross-linking are a safe and effective option in the management of mild and moderate keratoconus. (hindawi.com)
  • Keratoconus is a chronic bilateral noninflammatory corneal degeneration, characterized by localized corneal thinning and corneal steepening, leading to irregular astigmatism and impaired visual acuity [ 1 ]. (hindawi.com)
  • Corneal collagen cross-linking has found a broad international application for keratoconus in recent years [ 2 , 3 ]. (hindawi.com)
  • Topography-guided PRK to correct ametropia and irregular astigmatism in form fruste and frank keratoconus was introduced over a decade ago [ 7 - 9 ] with good results. (hindawi.com)
  • Kanellopoulos and Binder were the first to combine CXL with topography-guided PRK in the management of keratoconus. (hindawi.com)
  • Since then, several studies have evaluated the simultaneous use of topography-guided PRK followed immediately by CXL in progressive keratoconus [ 9 , 11 - 13 ]. (hindawi.com)
  • The aim of this study is to evaluate the effectiveness of combined corneal collagen cross-linking and topography-guided PRK in cases of mild and moderate keratoconus using an advanced ablation software with the Quest laser platform (Nidek, Gamagori, Japan). (hindawi.com)
  • When dealing with corneal abnormalities, such as keratoconus or irregular astigmatism, specialists should decide whether a corneal topography system is more valuable than a keratometer. (medwow.com)
  • To investigate the longitudinal changes in corneal topographic indices over time in patients with mild keratoconus (KC) and to determine predictive factors for the increase in corneal curvature. (arvojournals.org)
  • Purpose To assess the refractive improvements and the corneal endothelial safety of an individualised topography-guided regimen for corneal crosslinking in progressive keratoconus. (bmj.com)
  • Thirty-seven patients (50 eyes) with progressive keratoconus planned for corneal crosslinking were included. (bmj.com)
  • Conclusions Individualised topography-based crosslinking treatment centred on the ectatic cone has the potential to improve the corneal shape in keratoconus with decreased spherical refractive errors and improved visual acuity, without damage to the corneal endothelium. (bmj.com)
  • Topography and photokeratoscope maps can disclose pathologic conditions such as keratoconus , in which there is distortion of surface curvature, significant topographic asymmetry, and abnormal steepening of the central area of the cornea (orange and red in the map). (la-sight.com)
  • Accelerated corneal collagen cross-linking yielded results similar to those of conventional cross-linking while markedly reducing exposure time with the same treatment dose, according to a study.The case series study included 39 eyes of 22 patients with keratoconus. (linkoph.com)
  • You may be a candidate for corneal transplantation if you have been diagnosed with keratoconus, which causes your cornea to become thin and cone-shaped, or when an inherited corneal dystrophy, such as Fuchs' dystrophy, results in vision-impairing corneal swelling and clouding. (dukehealth.org)
  • These include lenses that are designed to fit post-LASIK/PRK eyes, post-corneal transplant eyes, and eyes with keratoconus. (vistaeyecareco.com)
  • To develop and compare deep learning (DL) algorithms to detect keratoconus on the basis of corneal topography and validate with visualization methods. (arvojournals.org)
  • We retrospectively collected corneal topographies of the study group with clinically manifested keratoconus and the control group with regular astigmatism. (arvojournals.org)
  • The DL models had fair accuracy for keratoconus screening based on corneal topographic images. (arvojournals.org)
  • These high accuracy CNN models can aid ophthalmologists in keratoconus screening with color-coded corneal topography maps. (arvojournals.org)
  • Keratoconus is a noninflammatory corneal disease characterized by stromal thinning, anterior protrusion, and irregular astigmatism. (arvojournals.org)
  • The morphological characterization of the cornea using corneal topographers is a widespread clinical practice that is essential for the diagnosis of keratoconus. (biomedcentral.com)
  • This paper describes the technologies in which current corneal topographers are based on, being possible to define the main morphological characteristics that the keratoconus pathology produces on corneal surface. (biomedcentral.com)
  • Finally, the main valuation indices, which are provided by the corneal topographers and used for the diagnosis of keratoconus, are also defined. (biomedcentral.com)
  • This article discusses the current technologies of corneal topographers and is aimed at: i) describing how they enable the main morphological measurements that produce the pathology of keratoconus on the corneal surface to be performed and ii) enumerating the main assessment indices provided by the topographers and used to diagnose keratoconus. (biomedcentral.com)
  • Review 8+ years of Clinical experience of surgical management of Keratoconus and other ectatic diseases using Topography Guided PRK + Corneal Crosslinking. (wcea.education)
  • Magdy Ezzat Khallaf ,Mohamed Ahmed El Mallah ,Rasha Hassan Ismail , Topography-guided photo-refractive keratectomy followed by corneal collagen cross-linking for keratoconus, Egypt. (who.int)
  • Corneal elevation and keratoconus indices in a 40- to 64-year-old population: Shahroud Eye Study. (ssmj.ru)
  • The optical quality in progressive keratoconus deteriorates due to ectasia and distortion of the corneal shape and optics. (biomedcentral.com)
  • Corneal irregularities in ectatic diseases such as keratoconus degrade the eye's optical quality and visual performance because of the increase in higher order aberrations (HOA) [ 1 ]. (biomedcentral.com)
  • Although the primary aim of corneal cross-linking (CXL) is to stop the progression of keratoconus ectasia, it may, as a welcomed side effect, also result in a decrease in corneal curvature and in a flattening of the apex. (biomedcentral.com)
  • Keratoconus patients with a minimal corneal thickness of 400 μm were offered CXL in case of confirmed disease progression. (biomedcentral.com)
  • The increased ROS levels and the oxidative stress both play a crucial role in the development of Fuchs endothelial corneal dystrophy , keratoconus, and granular corneal dystrophy type 2. (thefreedictionary.com)
  • The purpose of this evaluation is to assess the safety and efficacy of riboflavin-UVA induced cross-linking treatment for corneal ectasia due to keratoconus and LASIK keratectasia. (bioportfolio.com)
  • Placido disk corneal topography (PDCT) is the gold standard procedure to detect and diagnose corneal aberrations (i.e., keratoconus), analyze pre- and postoperative results of refractive surgery, and aid in contact lens fitting. (scielo.br)
  • Ten patients underwent anterior lamellar keratoplasty using a biosynthetic corneal stromal implant for either advanced keratoconus or central corneal scarring. (diva-portal.org)
  • Corneal topography, also known as photokeratoscopy or videokeratography, is a non-invasive medical imaging technique for mapping the surface curvature of the cornea, the outer structure of the eye. (wikipedia.org)
  • Nevertheless, topography in itself is a measurement of the first reflective surface of the eye (tearfilm) and is not giving any additional information beside the shape of this layer expressed in curvature. (wikipedia.org)
  • Corneal topography is a process for mapping the surface curvature of the cornea, similar to making a contour map of land. (eyehealthconsultants.com)
  • The Medmont E300 Corneal Topographer gives accurate mapping of the corneal curvature and that is integrated into Medmont Studio software environment. (shattky.co.nz)
  • Corneal Topography, as the name might suggest, is an imaging technique used to map out the curvature of your cornea (the front, clear part, of your eye). (maskelloptometrists.com)
  • This test, completed by approximately 93% of surgeons performing refractive procedures, is used to assess the shape and the curvature of the corneal surface. (medscape.com)
  • This test, using either scanning slit-beam or Scheimpflug technology, gives information about corneal thickness and posterior corneal curvature, in addition to the anterior corneal curvature information that is presented on standard corneal topographic maps. (medscape.com)
  • In this system, the corneal curvature was divided into 12 spots and measured in diopters (D) prior to the operation, 6 weeks postoperation and 12 weeks postoperation. (eyepress.ru)
  • From Fig., we could observe that there were at certain points in which the corneal curvature decreased at 6 weeks postoperation but increased again after 12 weeks postoperatively however there was no significant difference in corneal topography changes over time after horizontal muscle strabismus correction surgery with Wilks' Lambda = 0.971, F=2.895 and p=0.058. (eyepress.ru)
  • Factors that may change the corneal curvature measured using corneal topography in a normal eye include accommodation and external forces such as those exerted by the eye lid [6]. (eyepress.ru)
  • Suture and muscle placement are the mechanical forces that may alter the corneal curvature. (eyepress.ru)
  • If a muscle is placed too close to the limbus or tied to the sclera under tightly, the corneal curvature might be altered [2]. (eyepress.ru)
  • Although it has been reported that there are changes of the corneal curvature following extraocular muscle surgery, the effect was also known to be transient [2, 7]. (eyepress.ru)
  • These data demonstrate that the PAR CTS is both highly accurate and reproducible in determining topography of spheres that approximate the curvature of the human cornea. (nih.gov)
  • Corneal topography provides us with the most detailed possible information about the curvature of the eye and potential eyesight and eye disease issues. (ezekieleyes.com)
  • Computerized analysis of the diameter of the ring reflections can measure radius of curvature at specific points and across the entire corneal surface as a whole. (la-sight.com)
  • The even, symmetric curvature creates a topography map with very little variation across the surface. (la-sight.com)
  • Conductive Keratoplasty for Changing Corneal Curvature 11. (ophthabooks.eu)
  • Corneal topography is a computer assisted diagnostic tool that creates a three-dimensional map of the surface curvature of the cornea. (salandvision.com)
  • A computer-guided device creates a 3-D image map of your cornea to measure corneal power, curvature, and thickness. (dukehealth.org)
  • Small variations in corneal curvature originating from genetic disease, or post-surgical complications, can affect vision negatively. (vistaeyecareco.com)
  • he also proposed to photograph the image generated and to represent it on a diagram, which was aimed to analyze the variations in the curvature observed in the corneal surface. (biomedcentral.com)
  • He joined the discs to his photokeratoscope and examined the corneal photographs using a microscope in order to calculate the corneal curvature by a numerical algorithm. (biomedcentral.com)
  • The flattest, or lowest overall dioptric power is likely to be the most accurate measurement of corneal curvature. (thefreedictionary.com)
  • After topography-guided FS-LASIK, the 9-mm diameter epithelial thickness showed a longitudinal and regional non-uniform redistribution. (healio.com)
  • Optical coherence tomography (OCT) is a non-contact method of measuring the corneal epithelial thickness with good repeatability and reproducibility. (healio.com)
  • Scheimpflug corneal tomography is a three-dimensional imaging technique that characterizes the anterior/posterior corneal surfaces, along with corneal thickness distribution. (ophthalmologytimes.com)
  • The unoperated eye would be considered a good candidate for LASIK based on findings from standard screening methods, which included a normal front surface topography and central corneal thickness of 542 µm," he said. (ophthalmologytimes.com)
  • Corneal topographic parameters analyzed were the total astigmatism(TA), steep axis(SA), central corneal thickness(CCT), and anterior chamber depth(ACD). (arvojournals.org)
  • 4 Because KC progresses, contour and thickness measurements by corneal topography taken over time can help track the disease course. (arvojournals.org)
  • This invention discloses methods and systems for measuring corneal epithelial thickness and power, stromal thickness, subepitheila corneal power and topography. (octnews.org)
  • A pachymeter is a device used for the exact measurement of corneal thickness (accuracy 1 to 5 micrometers (μm) This is relevant for the correct determination of the intraocular pressure by tonometry, since the measured value is influenced by the corneal thickness in most common methods. (augenklinik-bern.ch)
  • With the result of the corneal thickness the actual intraocular pressure can be calculated. (augenklinik-bern.ch)
  • After applying an anesthetic drop to the cornea, a small pencil touches the corneal surface and measures the thickness using ultrasound. (augenklinik-bern.ch)
  • The surgeon replaces only certain layers of your cornea with donor tissue in these alternatives to full-thickness corneal transplant. (dukehealth.org)
  • You will see the doctor after watching the 3 videos and he will advise you what type of LASIK can be done depending on your corneal thickness and your degree of shortsightedness (doesn't mean you are suitable for the most expensive one). (lesterchan.net)
  • There is a negative correlation between optic disc size and corneal thickness and biomechanical properties. (scielo.br)
  • Use of ultrasonic pachymetry for measurement of changes in corneal thickness in mouse corneal transplant rejection. (biomedsearch.com)
  • The aims of this study were to (1) evaluate a pachymetry technique to measure changes in mouse corneal thickness and (2) correlate increases in transplant thickness with clinical and histological features of rejection. (biomedsearch.com)
  • Graft transparency was graded and corneal thickness measured by pachymetry on alternate days. (biomedsearch.com)
  • Stromal cellularity increased with increasing corneal thickness up to approximately 300 microm. (biomedsearch.com)
  • Working with Dan Reinstein, Dr. Silverman developed software for processing 3-D scans of the cornea that allowed measurement and mapping of corneal thickness as well as the thickness of the stroma and epithelium. (wikipedia.org)
  • This blade is a finer tool than the microkeratome used in laser assisted in situ keratomileusis (LASIK) so that it enables the surgeon to cut through the outer corneal epithelium without penetrating deeper corneal layers, specifically the Bowman layer, which promotes scar tissue formation. (medscape.com)
  • Allows your doctor to examine the cellular structure of your cornea and to see normal and abnormal cells in the various corneal layers (epithelium, Bowman's layer, stroma, Descemet's membrane, and endothelium) as well as infectious cells such as fungi and amoeba. (dukehealth.org)
  • 17. Alvarado J, Murphy C, Juster R. Age-related changes in the basement membrane of the human corneal epithelium. (ssmj.ru)
  • This study investigates the use of single-fit lenses for ortho-k and how they effect the corneal epithelium. (clspectrum.com)
  • LASEK and PRK permanently change the shape of the anterior central cornea using an excimer laser to ablate (remove by vaporization) a small amount of tissue from the corneal stroma at the front of the eye, just under the corneal epithelium . (wikipedia.org)
  • With PRK, the corneal epithelium is removed and discarded, allowing the cells to regenerate after the surgery. (wikipedia.org)
  • 19],[20] Normal corneal nerves are important in maintaining the homeostasis of corneal epithelium, but their injury can cause corneal dystrophy , which may be one pathogenesis for diabetic keratopathy. (thefreedictionary.com)
  • The technique involves topical application of riboflavin/dextran solution onto eye after removal of corneal epithelium. (bioportfolio.com)
  • Tomographic normal values for corneal elevation and pachymetry in a hyperopic population. (ssmj.ru)
  • CONCLUSION: In vivo graft pachymetry provides a new and reliable way to objectively diagnose rejection in the mouse model of corneal transplantation. (biomedsearch.com)
  • Another report presented the case of a patient who developed post-LASIK ectasia despite being considered at low risk based on preoperative topographic evaluation.12 Findings from corneal tomographic and biomechanical measurements identified ectasia risk in the fellow unoperated eye. (ophthalmologytimes.com)
  • The system produces a true topographic map (elevation map) by analyzing a projected grid on the corneal surface, as opposed to a placido disk reflection, and utilizes the technique of raster photogrammetry to define elevation points on the corneal surface. (nih.gov)
  • Shown above is a topography study reflecting mild topographic asymmetry. (la-sight.com)
  • Computer software digitizes these data points to produce a printout of the corneal shape, using assorted colors to identify different elevations, much like a topographic map of the earth displays changes in the land surface. (salandvision.com)
  • As you look at the bowl, the topography machine uses a series of data points to measure the "highs and lows" of your cornea, creating a corneal map that's similar to a topographic map of geographic features. (drleaks.com)
  • Pterygium surgery significantly reduces corneal topographic astigmatism and improves contrast sensitivity. (dovepress.com)
  • For patients with an atypical corneal shape, VK is a helpful process, particularly for refractive surgery and contact lens candidates. (medwow.com)
  • Orbscan Corneal Mapping in Refractive Surgery 6. (ophthabooks.eu)
  • Corneal topography provides a detailed "map" of your cornea that's important for contact lens fitting, laser refractive surgery, and diagnosing and managing issues that affect the cornea. (drleaks.com)
  • These masks were centered on the exposed corneal stroma between the laser beam and the eye, successively starting with the 4.5-mm mask, followed by the 4-mm mask, and, finally, the 3.5-mm mask, to allow the final ablation pattern to reveal a central graduated steepening comprised of 3 concentric rings. (medscape.com)
  • Transparent lenses on the patient's corneal stroma allowed visualization of the fixation light. (medscape.com)
  • New blood vessels originating from the corneal veins and extending from the limbus into the adjacent CORNEAL STROMA. (bioportfolio.com)
  • Neovascularization in the superficial and/or deep corneal stroma is a sequel to numerous inflammatory diseases of the ocular anterior segment, such as TRACHOMA, viral interstitial KERATITIS, microbial KERATOCONJUNCTIVITIS, and the immune response elicited by CORNEAL TRANSPLANTATION. (bioportfolio.com)
  • The principle of the procedure is to induce collagen crosslinking of the corneal stroma by the using riboflavin/UVA-treatment. (bioportfolio.com)
  • Several case reports and small uncontrolled trials have been published on the combination of this treatment with corneal cross linking (CCL) in patients with ectatic corneal diseases. (clinicaltrials.gov)
  • This randomized study will evaluate the safety and efficacy of a combined treatment of corneal cross linking with a partial topography guided excimer laser treatment in eyes with progressive ectatic corneal diseases. (clinicaltrials.gov)
  • Your corneal surgeon will conduct a thorough examination of your eye and its structures using a variety of imaging devices to help diagnose any corneal disorders or diseases. (dukehealth.org)
  • Corneal topography typically is only performed in patients who may be at risk for certain eye diseases or conditions, who wear or want to wear contact lenses, or who have vision issues that the doctor feels might be related to or involve the cornea. (drleaks.com)
  • Detection of ectatic corneal diseases based on Pentacam. (ssmj.ru)
  • This new technology permits earlier diagnosis of many corneal diseases, provides vital information to eye surgeons for preoperative and post-operative decision making and provides helpful information for the fitting of contact lenses. (uic.edu)
  • We will also examine for any potentially sight-threatening conditions such as corneal ulcers, glaucoma, retinal diseases, and optic nerve disorders. (np.edu.sg)
  • The biosynthetic stromal substitutes (BSS) characterized herein represent a potentially safe alternative to donor organ transplantation for anterior corneal stromal diseases. (diva-portal.org)
  • The third in the ASCRS Phaco FUNdamentals series, this webinar will address how the cataract and refractive surgeon can best optimize topography and tomography to achieve better surgical results and will discuss anterior segment imaging. (ascrs.org)
  • To observe the epithelial remodeling over a 9-mm diameter cornea induced by topography-guided femtosecond laser-assisted in situ keratomileusis (FS-LASIK) for myopia correction using spectral-domain optical coherence tomography (SD-OCT). (healio.com)
  • Corneal tomography represents a major advance for diagnosis, prognosis, and treatment planning, but there remains a need for classic imaging technologies, such as Placido topography, along with a comprehensive clinical evaluation, said Renato Ambrósio Jr., MD, PhD. (ophthalmologytimes.com)
  • The integrated Scheimpflug-based corneal tomography and biomechanical analysis provided with the Pentacam and Corvis systems (both Oculus) generates the Tomographic and Biomechanical Index (TBI), which was developed to enhance diagnostic sensitivity, he said. (ophthalmologytimes.com)
  • Objective: The aim was to compare the corneal topography and tomography parameters of macular corneal dystrophy (MCD) granular corneal dystrophy (GCD) and lattice corneal dystrophy (LCD) patients obtained by Scheimpflug imaging system. (thefreedictionary.com)
  • Optic disc area and geometry was accessed by HRT III ( Heidelberg Retina Tomography - Heidelberg eng ), Pentacam (Oculus) was used for accessing IOP and corneal parameters and ORA ( Ocular Response Analyze - Reichert) was utilized to access corneal biomechanical properties. (scielo.br)
  • Topography guided laser treatment enables the surgeon to correct higher order aberrations in corneas with irregular astigmatism. (clinicaltrials.gov)
  • This corneal thinning induces irregular astigmatism, myopia, and protrusion, which leads to mild to marked impairment in vision quality. (arvojournals.org)
  • These conditions can produce corneal shape anomalies such as irregular astigmatism that result in visual impairment. (bondfamilyeyecare.com)
  • This analysis attempts to depict optical aberration of the corneal surface in an effort to find irregular astigmatism and refractive error. (medscape.com)
  • Visual acuity, refraction, keratometry (K1, K2 and K max ) and corneal endothelial morphometry were assessed preoperatively and at 1, 3, 6 and 12 months postoperatively. (bmj.com)
  • Outcome measures will be induced corneal refractive change (Fourier power vector analysis), ISV change, and visual acuity, at 6 months. (clinicaltrials.gov)
  • In addition to corneal transparency, regularity of the anterior surface is an important factor in visual acuity after DSEK. (biomedsearch.com)
  • A corneal topographer projects a series of illuminated rings, referred to as a placido disc, onto the surface of the cornea, which are reflected back into the instrument. (verywellhealth.com)
  • Instead of just measuring two points, a corneal topographer can measure hundreds and even thousands of data points to build a much more precise color map of the overall steepness of the eye in any location the doctor is interested in. (verywellhealth.com)
  • A corneal topographer will be able to show how rough the surface is and how a dry eye may be affecting your vision. (verywellhealth.com)
  • Corneal topography is performed with a non-contact instrument called a corneal topographer. (bondfamilyeyecare.com)
  • Using computerized imaging technology, the 3-dimensional map produced by the corneal topographer aids an ophthalmologist in the diagnosis, monitoring, and treatment of various visual conditions. (eyehealthconsultants.com)
  • The corneal topographer is made up of a computer linked to a lighted bowl that contains a pattern of concentric rings. (eyehealthconsultants.com)
  • A corneal topographer is a specialized computerized equipment that is used to map the surface of the eye. (healthchoicesfirst.com)
  • All measurements were obtained with Haag-Streit corneal topographer. (eyepress.ru)
  • At Ezekiel Eyes we use computerized imaging technology, and the 3-dimensional map produced by the corneal topographer aids us in the diagnosis, monitoring, and treatment of various visual conditions. (ezekieleyes.com)
  • In our practice, we use the E300 Corneal Topographer from Medmont (and distributed in the United States by Nidek, Inc). The E300 analyzes 102,000 corneal points with a standard deviation of error of less than 2 microns and is capable of measuring the cornea from limbus to limbus. (optometricoffice.com)
  • began studying this issue by re-purposing the corneal topographer to measure the surface profile of four commercially available brands of soft, simultaneous-designed, multifocal contact lenses. (specialeyesqc.com)
  • Corneal scans using our Zeiss Atlas 9000 Corneal Topographer allows our doctors to view the cornea in a more detailed way than is afforded with only our biomicroscopes. (vistaeyecareco.com)
  • The information the corneal topographer provides is useful in monitoring disease, diagnosing disease, fitting custom contact lenses, and is used in Myopia Management . (vistaeyecareco.com)
  • The corneal topographer picks up the distortion of the cornea that is typical of this disease and leads to our ability to diagnose the cause of vision loss. (vistaeyecareco.com)
  • The first fully automated corneal topographer was called Corneal Modeling System (CMS-1), developed by Computed Anatomy Inc. (New York, USA). (biomedcentral.com)
  • You may also be a candidate for corneal transplantation if your cornea has been damaged by infection, scarring, or trauma. (dukehealth.org)
  • BACKGROUND/AIMS: Diagnosis of rejection in the mouse model of corneal transplantation is based on subjective judgement of loss of graft transparency. (biomedsearch.com)
  • Future studies will indicate if biomaterials technology will allow for the optimization of postoperative surface irregularity after anterior stromal replacement, a new window of opportunity that is not available with traditional corneal transplantation techniques. (diva-portal.org)
  • A development of keratoscopy, corneal topography extends the measurement range from the four points a few millimeters apart that is offered by keratometry to a grid of thousands of points covering the entire cornea. (wikipedia.org)
  • Keratometry: Before computerized corneal topographers were invented, a keratometer was used to measure a small area in the central cornea. (verywellhealth.com)
  • Objective: To determine the effect of 23-gauge pars plana vitrectomy on corneal dioptric power through a comparison of difference in preand postsurgery keratometry. (thefreedictionary.com)
  • To highlight the misalignment between the center of the multifocal optics and a patient's visual axis, Dr. Lampa first performed corneal topography for 18 subjects without contact lenses on the eye. (specialeyesqc.com)
  • Corneal topography involves measuring subtle variations in a patient's corneal curvatures. (vistaeyecareco.com)
  • Later, in the mid-nineteenth century, the Goode keratoscope appeared and enabled a corneal examination using the lateral reflection of a bright square object projected onto the patient's cornea. (biomedcentral.com)
  • The corneal topograph owes its heritage to the Portuguese ophthalmologist Antonio Placido, who, in 1880, viewed a painted disk (Placido's disk) of alternating black and white rings reflected in the cornea. (wikipedia.org)
  • Example of placido based corneal topography. (medscape.com)
  • In placido-based topography, a series of light rings is projected onto the eye, outlining the cornea. (medscape.com)
  • Current corneal topography is based on the development of the Goode keratoscope by Antonio Placido da Costa [ 3 ], who developed it in 1880. (biomedcentral.com)
  • Corneal topographers based on this technology, also called videokeratoscopes, are based on the application of the principles of convex mirrors' geometrical optics to an instrument in which the rings or Placido discs with known size and spacing are reflected on the anterior surface of the cornea. (biomedcentral.com)
  • In India, ocular trauma, infectious keratitis, corneal ulceration and post-infectious keratitis corneo-iridic scars contribute significantly to the paediatric ocular morbidity whereas in adults, the major causes of corneal blindness include bacterial, fungal or viral keratitis, hereditary corneal dystrophy and eye injuries. (thefreedictionary.com)
  • However, prices have fallen substantially over time, bringing corneal topographs into the budget of smaller clinics and increasing the number of patients that can be examined. (wikipedia.org)
  • Topography Guided Excimer Laser Surface Ablation in Combination With Corneal Cross-linking (CCL) in Patients With Progressive Ectatic Corneal Disorders. (clinicaltrials.gov)
  • Patients will receive a topography guided laser treatment in combination with a standard corneal cross linking treatment in the same session. (clinicaltrials.gov)
  • Forty-three eyes of 22 patients who underwent topography-guided FS-LASIK for myopic correction were included. (healio.com)
  • The TBI was developed by Dr. Ambrósio and colleagues in a multicenter study including one randomly selected eye from subgroups of patients with normal (n = 480) or keratoconic corneas (n = 204) and using the random forest method with leave-one out cross-validation, an efficient artificial intelligence technique for classification.1 The study also included 94 eyes with normal topography from patients with VAE. (ophthalmologytimes.com)
  • Several adjuvant therapies in combination with CXL have been proposed in an effort to develop a technique that can offer patients keratectasia corneal stability together with improved functional vision, including intracorneal rings [ 5 ] and phakic intraocular lenses [ 6 ]. (hindawi.com)
  • This study was performed to evaluate the changes of corneal astigmatism in patients undergoing orbital decompression surgery. (arvojournals.org)
  • Study subjects were strabismus patients under the care of Eye Clinic, Universiti Kebangsaan Malaysia medical centre, planned for strabismus correction involving horizontal rectus muscles and cooperative for corneal topography and objective refraction. (eyepress.ru)
  • Corneal topography becomes a crucial step in determining the correct lens parameters for our patients. (optometricoffice.com)
  • Using corneal mapping to look at the distribution of power becomes important when fitting patients for myopia control. (optometricoffice.com)
  • Patients with FFKC who seek laser vision correction should be dissuaded from having LASIK (sculpting under a thin flap of superficial tissue), but may be candidates for PRK, which renders teh sculpting on the outermost layer of corneal collagen. (la-sight.com)
  • Methodology: the present study was designed to evaluate simultaneous topography-guided partial PRK and CXL as a therapeutic intervention in patients with KC. (who.int)
  • The purpose of the study was to analyze corneal topography in patients with cataract after previous anterior radial keratotomy Material and Methods. (ssmj.ru)
  • Optimization of the calculation of the optical power of the toric IOL in patients with cataracts and altered corneal topography. (ssmj.ru)
  • Overall, our novel approach of combined EK and MICS can be performed for patients with Fuchs' corneal dystrophy and dense cataract. (thefreedictionary.com)
  • It also can be used before contact lens fittings and corneal transplants and for patients with other corneal problems. (clevelandclinic.org)
  • The goal of this phase 1 safety study was to characterize the three-dimensional (3D) corneal shape of the first 10 human patients implanted with a BSS and assess its stability over time. (diva-portal.org)
  • After a mean 40.1 ± 12.4 months since ELLK they underwent combined simultaneous corneal regularization treatment with topographically guided transepithelial excimer laser PRK (central corneal regularization) and corneal CXL induced by riboflavin-ultraviolet A. (dovepress.com)
  • After allowing lenses to settle and confirming appropriate fit with a slit lamp exam, each of the subjects then underwent corneal topography while wearing five different commercially available soft multifocal contact lenses. (specialeyesqc.com)
  • By incorporating full corneal topography and wavefront analysis of the cornea the ALADDIN addresses the limitations of conventional biometers. (topconhk.com)
  • A topography guided excimer laser treatment will be performed prior to CCL in one session. (clinicaltrials.gov)
  • Each technique focuses on creating an epithelial flap under which an excimer laser is used to sculpt the corneal tissue. (medscape.com)
  • While corneal cross-linking (CXL) aims at stopping disease progression, "CXL-Plus" combines CXL with excimer laser ablation to improve visual function. (biomedcentral.com)
  • Central Corneal Regularization (CCR) represents a therapeutic excimer laser modality specifically designed to smoothen the ectatic corneal shape and to reduce higher order aberrations (HOA). (biomedcentral.com)
  • A comprehensive ophthalmological examination was performed, including the topography of the cornea using a Pentacam HR apparatus (Oculus, Germany) with the determination of elevation points of the anterior cornea. (ssmj.ru)
  • Normative Pentacam anterior and posterior corneal elevation measurements: effects of age, sex, axial length and white-to-white. (ssmj.ru)
  • Qualitative analysis selected 10 EyeSys and 15 Pentacam topographies used in the quantitative evaluation. (scielo.br)
  • The factors that influence a normal corneal topography are not well understood. (eyepress.ru)
  • A normal corneal topography study is shown above. (la-sight.com)
  • Duke corneal surgeons have extensive experience and perform hundreds of corneal transplants each year using the latest advances. (dukehealth.org)
  • Instead of ultrasound, this computer uses a mild beam of laser to measure the axial length and corneal measurements.This has its ownprogram for calculating the proper intraocular lens powers. (rockymountaineye.com)
  • To introduce a new convenient and accurate method to measure the angle kappa using ultrasound biomicroscopy (UBM) and corneal topography . (bvsalud.org)
  • The mechanism of topography-guided ablation is the fitting of an ideal corneal shape (usually a sphere) under the present topography map with the ablation of tissue in between. (hindawi.com)
  • However, the fact that cross-linked corneas may have a different ablation rate from normal corneas-which could lead to unpredictable PRK results-and the hypothesis that the removal of the cross-linked corneal tissue by the PRK procedure could decrease the stiffening effects of the CXL treatment in addition to the increased possibility of haze formation after PRK were serious limitations [ 3 ]. (hindawi.com)
  • Centration Analysis of Ablation Over the Coaxial Corneal Light Reflex for Hyperopic LASIK. (specialeyesqc.com)
  • The technique routinely used for hyperopic LASIK uses a 110- to 160-µm thick corneal flap and a wide ablation with a peripheral blend zone. (medscape.com)
  • The corneal topography map is used in conjunction with other tests to determine exactly how much corneal tissue will be removed to correct the visual defect. (eyehealthconsultants.com)
  • There are several types of corneal transplant procedures to remove damaged, unhealthy cornea tissue. (dukehealth.org)
  • During this procedure -- also called penetrating keratoplasty (PK) -- the corneal transplant surgeon removes all layers of the diseased cornea and replaces it with clear, healthy cornea tissue from a donor. (dukehealth.org)
  • Restores vision by removing the severely damaged or diseased cornea and replacing it with an acrylic artificial cornea and donor corneal tissue that is sutured in place. (dukehealth.org)
  • the pattern and sequence selected to allow a cloud of ablated corneal tissue particles to dissipate in one place before contacting that place again with another laser shot. (google.com)
  • The current and projected shortage of transplantable human donor corneas has prompted the development of long-term alternatives to human donor tissue for corneal replacement. (diva-portal.org)
  • [ 5 ] Photorefractive keratectomy (PRK) has been used successfully for hyperopia but has problems of regression, induced astigmatism, and corneal haze, thereby limiting its usefulness to the correction of mild hyperopia only. (medscape.com)
  • This device was a variant that allowed a precise measurement of the anterior corneal surface through the projection of a circular plate onto the cornea. (biomedcentral.com)
  • Findings from anecdotal case reports are supported by clinical studies to highlight the relevance of advances in corneal imaging to help evaluating the cornea. (ophthalmologytimes.com)
  • Computer-assisted corneal topography devices have become indispensable for diagnosing subclinical/clinical KC and for evaluating disease progression. (arvojournals.org)
  • Early and late clinical landmarks of corneal dystrophies. (medlineplus.gov)
  • PC-2 or Jackson-Lawler syndrome is characterized by natal or prenatal teeth (15-50%), numerous steatocystomas and various other cystic lesions (25%), hair abnormalities (9-25%), and corneal dystrophy (8%), in addition to clinical features of PC-1 but with less severe keratodermas. (thefreedictionary.com)
  • To compare the clinical outcome 2 years after corneal collagen cross-linking (CXL) with conventional and accelerated ultraviolet A (UVA) irradiation using riboflavin with hydroxypropyl methylcellulose. (bioportfolio.com)
  • A standard corneal cross linking procedure will be performed in this arm. (clinicaltrials.gov)
  • They introduced a two-step procedure with CXL performed first and topography-guided PRK after a 1-year interval [ 2 ]. (hindawi.com)
  • Corneal topography is a procedure used to monitor and measure changes that may occur to the shape and integrity of the cornea of your eye. (verywellhealth.com)
  • Outcome measured was changes of the corneal topography before strabismus correction surgery and after the procedure. (eyepress.ru)
  • The procedure is typically recommended when less-invasive corneal disease treatments, such as special glasses or contact lenses, and medications to reduce swelling cannot halt the progression of your corneal disease. (dukehealth.org)
  • Corneal transplant surgery -- also called keratoplasty -- preserves or restores vision impaired by advanced corneal disease or when the cornea has been damaged by scarring, trauma, or infection. (dukehealth.org)
  • Effect of anterior and posterior corneal surface irregularity on vision after Descemet-stripping endothelial keratoplasty. (biomedsearch.com)
  • Corneal topography is used in diagnosing certain types of problems, in evaluating a disease's progression and in the fitting of contact lenses. (ezekieleyes.com)
  • Results of corneal mapping over commercially available soft multifocal contact lenses. (specialeyesqc.com)
  • People who wear contact lenses are also at risk for corneal damage from lenses that don't fit properly or are not properly cleaned or worn as directed. (drleaks.com)
  • Different types of topography maps can help you better evaluate the eye's anterior surface and fit contact lenses. (clspectrum.com)
  • The materials used to make the corneal shield all have a history of use in medical devices, contact lenses, and/or corneal shields and have been used safely in the eye. (stanford.edu)
  • METHODS: Corneal data were acquired using a rotating Scheimpflug camera before and 1 month and 3 months after DSEK. (biomedsearch.com)
  • In the quest for enhanced ectasia diagnosis, we have to go beyond topography, which only provides two-dimensional information about the front surface of the cornea,' said Dr. Ambrósio, professor of ophthalmology, Federal University of the State of Rio de Janeiro (UniRIO), Brazil. (ophthalmologytimes.com)
  • The main outcome measures were changes in refractive errors and corneal endothelial cell density. (bmj.com)
  • No corneal endothelial cell loss was seen after either treatment. (bmj.com)
  • METHODS: Orthotopic corneal allografts (C57BL/6 strain donor) and syngeneic grafts were performed in A/J mice. (biomedsearch.com)
  • The endothelial camera is used to measure the number and size of cells on the inside of the cornea (corneal endothelium), which have the function of pumping water out of the cornea. (augenklinik-bern.ch)
  • The tests carried out include corneal topography (mapping the surface of the cornea), fundus photography (capturing a photo of the back of the eye), tonometry (measurement of pressure in the eye) and visual fields analysis. (opticalexpress.co.uk)
  • By measuring the distance between these rings at various points, the unit creates a color-coded map that illustrates the contour of the corneal surface. (medscape.com)
  • The computerized corneal topography measures this important surface giving us a color coded display containing detailed information about the shape of your cornea. (eyefreedom.com)
  • Microbiological findings and predisposing risk factors in corneal ulcers. (nih.gov)
  • Schnyder dystrophy is a slowly progressive corneal dystrophy with autosomal dominant inheritance. (thefreedictionary.com)
  • This situation went on for another year before she was eventually diagnosed with corneal dystrophy in 2011. (thefreedictionary.com)
  • Anterior and posterior corneal elevation data were decomposed into a set of Zernike polynomials up to the 8th order within a 4.0 mm diameter region. (biomedsearch.com)
  • Central corneal regularization (CCR) is a novel, customized, topography-guided, transepithelial PRK treatment specifically developed for combined use with CXL (iVIS™ platform, Ligi Tecnologie Medicali S.r.l. (biomedcentral.com)
  • Using Astig PLOT TM , the mean surgically induced astigmatism (SIA) was 0.21±0.88D with the axis of 46±22° which suggest that decompression surgery did change the corneal shape and induced incyclotorion of the steepest axis. (arvojournals.org)
  • Several types of topography are noted (see the image below). (medscape.com)
  • This information is useful to evaluate and correct astigmatism, monitor corneal disease, and detect irregularities in the corneal shape. (ezekieleyes.com)
  • Corneal mapping allows us to evaluate important corneal characteristics necessary for an optimal contact lens fit. (optometricoffice.com)
  • We can actually evaluate thousands of corneal data points on a single map. (optometricoffice.com)
  • Prospective, randomized multicenter study to determine the safety and effectiveness of performing corneal collagen cross-linking (CXL) using riboflavin and UVA light in eyes with ectasia a. (bioportfolio.com)
  • Corneal Ectasia Post-Lasik: The Orbscan Advantage 5. (ophthabooks.eu)
  • Corneal ectasia is a relative weakness in the structure of the cornea, which produces a progressive change in its shape which results in visual distortion. (bioportfolio.com)
  • A camera is used to obtain digital images (photos), or a computerized low-power imaging scanning system is used to obtain thousands of images in a few seconds (OCT). Image patterns can be used to diagnose and/or follow various retinal, optic nerve, and corneal conditions. (clevelandclinic.org)
  • The greatest advantage of corneal topography is its ability to detect conditions invisible to most conventional testing. (eyehealthconsultants.com)
  • By specifically focusing on oscillations of light waves within the optical path to depict the exiting locus of light points as they relate to the pupillary plane, the technology may detect corneal and lenticular imperfection. (medscape.com)
  • The greatest advantage of the computerized corneal topography is that it can detect conditions too subtle or invisible to even the most thorough conventional testing. (eyefreedom.com)