Corneal Topography: 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.Keratoconus: 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)Cornea: 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)Lasers, Excimer: 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, Ocular: Refraction of LIGHT effected by the media of the EYE.Astigmatism: 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)Photorefractive Keratectomy: 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.Keratomileusis, Laser In Situ: 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.Myopia: 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.Corneal Diseases: Diseases of the cornea.Refractive Surgical Procedures: 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.Keratoplasty, Penetrating: Partial or total replacement of all layers of a central portion of the cornea.Aberrometry: 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.Visual Acuity: 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.Refractive Errors: Deviations from the average or standard indices of refraction of the eye through its dioptric or refractive apparatus.Image Processing, Computer-Assisted: 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.Disease Progression: 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.Quantitative Structure-Activity Relationship: 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.Contact Lenses: Lenses designed to be worn on the front surface of the eyeball. (UMDNS, 1999)Prosthesis Fitting: The fitting and adjusting of artificial parts of the body. (From Stedman's, 26th ed)Strabismus: 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)Oculomotor Muscles: 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.Contact Lenses, Extended-Wear: Hydrophilic contact lenses worn for an extended period or permanently.BrazilKinetoplastida: An order of flagellate protozoa. Characteristics include the presence of one or two flagella arising from a depression in the cell body and a single mitochondrion that extends the length of the body.Ants: Insects of the family Formicidae, very common and widespread, probably the most successful of all the insect groups. All ants are social insects, and most colonies contain three castes, queens, males, and workers. Their habits are often very elaborate and a great many studies have been made of ant behavior. Ants produce a number of secretions that function in offense, defense, and communication. (From Borror, et al., An Introduction to the Study of Insects, 4th ed, p676)Dielectric Spectroscopy: A technique of measuring the dielectric properties of materials, which vary over a range of frequencies depending on the physical properties of the material. The technique involves measuring, over a range of frequencies, ELECTRICAL IMPEDANCE and phase shift of an electric field as it passes through the material.DNA, Kinetoplast: DNA of kinetoplasts which are specialized MITOCHONDRIA of trypanosomes and related parasitic protozoa within the order KINETOPLASTIDA. Kinetoplast DNA consists of a complex network of numerous catenated rings of two classes; the first being a large number of small DNA duplex rings, called minicircles, approximately 2000 base pairs in length, and the second being several dozen much larger rings, called maxicircles, approximately 37 kb in length.PeruCorneal Surgery, Laser: Surgical techniques on the CORNEA employing LASERS, especially for reshaping the CORNEA to correct REFRACTIVE ERRORS.Optometry: The professional practice of primary eye and vision care that includes the measurement of visual refractive power and the correction of visual defects with lenses or glasses.Attentional Blink: Temporary visual deficit or impaired visual processing occurring in a rapid serial visual presentation task. After a person identifies the first of two visual targets, the ability to detect the second target is impaired for the next few hundred milliseconds. This phenomenon is called attentional blink.Muscidae: A family of the order DIPTERA with over 700 species. Important species that may be mechanical vectors of disease include Musca domesticus (HOUSEFLIES), Musca autumnalis (face fly), Stomoxys calcitrans (stable fly), Haematobia irritans (horn fly) and Fannia spp.Forensic Sciences: Disciplines that apply sciences to law. Forensic sciences include a wide range of disciplines, such as FORENSIC TOXICOLOGY; FORENSIC ANTHROPOLOGY; FORENSIC MEDICINE; FORENSIC DENTISTRY; and others.Ophthalmology: A surgical specialty concerned with the structure and function of the eye and the medical and surgical treatment of its defects and diseases.Encyclopedias as Topic: Works containing information articles on subjects in every field of knowledge, usually arranged in alphabetical order, or a similar work limited to a special field or subject. (From The ALA Glossary of Library and Information Science, 1983)MedlinePlus: NATIONAL LIBRARY OF MEDICINE service for health professionals and consumers. It links extensive information from the National Institutes of Health and other reviewed sources of information on specific diseases and conditions.Consumer Health Information: Information intended for potential users of medical and healthcare services. There is an emphasis on self-care and preventive approaches as well as information for community-wide dissemination and use.Social Media: Platforms that provide the ability and tools to create and publish information accessed via the INTERNET. Generally these platforms have three characteristics with content user generated, high degree of interaction between creator and viewer, and easily integrated with other sites.Dissent and Disputes: Differences of opinion or disagreements that may arise, for example, between health professionals and patients or their families, or against a political regime.Internet: A loose confederation of computer communication networks around the world. The networks that make up the Internet are connected through several backbone networks. The Internet grew out of the US Government ARPAnet project and was designed to facilitate information exchange.Lacrimal Apparatus Diseases: Diseases of the lacrimal apparatus.Dry Eye Syndromes: Corneal and conjunctival dryness due to deficient tear production, predominantly in menopausal and post-menopausal women. Filamentary keratitis or erosion of the conjunctival and corneal epithelium may be caused by these disorders. Sensation of the presence of a foreign body in the eye and burning of the eyes may occur.Tears: The fluid secreted by the lacrimal glands. This fluid moistens the CONJUNCTIVA and CORNEA.Eyelid DiseasesFluorescein: A phthalic indicator dye that appears yellow-green in normal tear film and bright green in a more alkaline medium such as the aqueous humor.Meibomian Glands: The sebaceous glands situated on the inner surface of the eyelids between the tarsal plates and CONJUNCTIVA.Fluorophotometry: Measurement of light given off by fluorescein in order to assess the integrity of various ocular barriers. The method is used to investigate the blood-aqueous barrier, blood-retinal barrier, aqueous flow measurements, corneal endothelial permeability, and tear flow dynamics.Commonwealth of Independent StatesEurope, EasternUSSRTajikistanPatents as Topic: Exclusive legal rights or privileges applied to inventions, plants, etc.Azerbaijan

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 ...
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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.
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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. ...
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,
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.. ...
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.
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
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
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.
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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 ...
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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., ...
Anjos Ferreira AL, Russell RM, Rocha N, Placido Ladeira MS, Favero Salvadori DM, Oliveira Nascimento MC, Matsui M, Carvalho FA, Tang G, Matsubara LS, Matsubara BB ...
Epithelial sheets fold into complex topographies that contribute to their function in vivo. Cells can sense and respond to substrate topography in their immediate vicinity by modulating their interfacial mechanics, but the extent to which these mechanical properties contribute to their ability to sense subst
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 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 ...
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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 ...
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 ...
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
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, ...
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 ...
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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 ...
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.
... 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 ...
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
Definition of posterior surface of tibia. Provided by Stedmans medical dictionary and Drugs.com. Includes medical terms and definitions.
It is a pleasure to be able to offer and follow my patients with cutting edge technology. Having access to the latest topographers, optical coherence tomograghy, non-dilated fundus cameras and the fastest visual fields analyzer makes diagnosing my patients quicker and the treatment more successful.". View Doctors Profile ...
Purpose To comprehensively assess the precision and agreement of anterior corneal power measurements using 8 different devices. Methods Thirty-five eyes from 35 healthy subjects were included in the prospective study. In the first session, a single examiner performed on each subject randomly measurements with the RC-5000 (Tomey Corp., Japan), KR-8000 (Topcon, Japan), IOLMaster (Carl Zeiss Meditec, Germany), E300 (Medmont International, Australia), Allegro Topolyzer (Wavelight AG, Germany), Vista (EyeSys, TX), Pentacam (Oculus, Germany) and Sirius (CSO, Italy). Measurements were repeated in the second session (1 to 2 weeks later). Repeatability and reproducibility of corneal power measurements were assessed based on the intrasession and intersession within-subject standard deviation (Sw), repeatability (2.77Sw), coefficient of variation (COV), and intraclass correlation coefficient (ICC). Agreement was evaluated by 95% limits of agreement (LoA). Results All devices demonstrated high repeatability and
Keratoconus Australia aims to raise awareness and understanding of Keratoconus.. We promote research into the causes, prevention and control of Keratoconus.. We also provide support to people with Keratoconus through dissemination of information, individual counselling and help lines. ...
Doctor answers on Symptoms, Diagnosis, Treatment, and More: Dr. Quinn on about how long does astigmatism last: Astigmatism is typically from an abnormal corneal shape or lens shape, and this anatomy usually doesnt change or cancel out on its own (need some kind of treatment like laser or lens surgery), but can be corrected for. for topic: About How Long Does Astigmatism Last
This tool allows you to look up elevation data by searching address or clicking on a live google map. This page shows the elevation/altitude information of 74 Gowing Dr, Meadowbank, Auckland, New Zealand, including elevation map, topographic map, narometric pressure, longitude and latitude.
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Using EDARBI TAB 80MG during pregnancy may raise the risk of children developing some disorder (commpon for some such kind of drugs), however it depends upon how EDARBI TAB 80MG ingredients pass through placenta and may have effect on baby - Strength of EDARBI TAB 80MG is major factor in determination of such side effects, The possible danger in pregnancy are under research. BAUSCH AND LOMB, S.A Canada publish leaflet about EDARBI TAB 80MG every update to describe possible risks of using EDARBI TAB 80MG side effect in pregnancy and pregnant women. You may download BAUSCH AND LOMB, S.A issued leaflet regarding side effects of EDARBI TAB 80MG - N/A. Pregnancy Side Effects can be easily know by Atc code of EDARBI TAB 80MG ATC CODE.. ...
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In certain embodiments, an ophthalmic lens comprises an optic. The optic has an optical axis and surfaces comprising an anterior surface and a posterior surface. At least one of the surfaces has an inner refractive region and a refractive-diffractive structure disposed outwardly from the inner refractive region in a direction away from the optical axis. The inner refractive region is adapted to contribute refractively to a distance focus optical power. The refractive-diffractive structure comprises one or more diffractive regions and one or more refractive regions. A diffractive region is adapted to contribute diffractively to a multi-zone optical power, and a refractive region is adapted to contribute refractively to the distance focus optical power.
Treat your corneal erosion or keratoconus with intacs cornea implants placed by Dr. Wong in Austin, Round Rock, Cedar Park, Leander & Buda TX. 512-345-5030
For management of keratoconus in Timonium, visit Eye To Eye at 1819 York Road, Timonium, MD 21093. Schedule an appointment by calling (410) 376-7070.
The trained ophthalmologists at Austin Eye offer Intacs corneal inserts, an alternative to corneal transplant surgery for the treatment of keratoconus.
Quickly and accurately gather reliable pretesting data with the cutting-edge ERK-9000 Autorefractor/Keratometer. Enjoy the flexibility of Bluetooth and remote connectivity with the entire Ezer Digital Practice line. Ezer digital practice platforms make it possible to perform a full digital vision exam, from pretest to Rx. The ERK-9000 offers your staff the opportunity to gather a wealth of precise information about the patient in one fast and easy test, making the remainder of your exam swift, simple, and exact. In addition to the wealth of functions youd expect from a top-of-the-line autorefractor/keratometer, the ERK-9000 features auto-shoot programming, an illumination mode, IOL, and so much more.. ...
Crystal: Crystal, any solid material in which the component atoms are arranged in a definite pattern and whose surface regularity reflects its internal symmetry. The definition of a
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The laser triangulation probe conveniently obtains surface topography data of a measured target. However, compared to the touch probe, its reliability and accuracy can be negatively affected by various factors associated with the object being measured and the probe itself. In this paper, to identify potential compensation strategies to improve the accuracy of depth measurement for laser triangulation probe, the measuring errors caused by an oil film on the measured surface, and the probe’s position and orientation parameters with respect to the measuring object (including scan depth, incident angle, and azimuth angle), were studied. A theoretical model based on the geometrical optics, and an empirical model from the error evaluations, were established to quantitatively characterize the error influence of oil film and probe’s parameters, respectively. We also investigated the influence pattern of different filtering methods with several comparison experiments. The verification procedures,
Bland-Altman plot of keratometric (K)-readings with the difference between the K-readings of the two methods regressed on the average of K-readings with its 95%
To obtain a database, containing at least two valid corneal Scheimpflug measurements recorded at least 5 months apart, of 1500 keratoconus patients ...
... is a condition where the cornea becomes thin and stretched near its center, causing it to bulge forward into a conical shape. The Lions Eye Institute specializes in the treatment for Keratoconus.
A lens having a semipermeable transparent sheath with opposite anterior and posterior portions joined at their edges and forming a closed interior space between themselves. A body of liquid is provided within the sheath and fills the interior space and constitutes an optical lens whose anterior and posterior surfaces are bounded by the anterior and posterior portions of the sheath, respectively, thus defining the anterior and posterior surfaces of the lens. A substance is provided in the body of liquid for producing within the interior space a concentration which is greater than the concentration of a liquid medium in association with which the lens is to be used, in consequence of which when the lens is in contact with such medium, the interior space will be kept filled with liquid under the influence of osmosis which causes the flow of liquid from the exterior of the sheath to the interior thereof whenever the interior space is less than full thereby maintaining the shape of the lens.
Keratoconus Treatment Centers offer a new hope to patients living with keratoconus eye disorder. Newer treatments, insurance coverage & low monthly payments
If ever the eye visualize a more conical shape, one might be suffering keratoconus, a condition where some alterations are happening in the cornea. abnormalities...
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Simultaneous intratunnel cross-linking with intrastromal corneal ring segment implantation versus simultaneous epithelium-off cross-linking with intrastromal corneal ring segment implantation for keratoconus management Mohamed Hosny, Moustafa Nour, Sarah Azzam, Mohsen Salem, Esraa El-Mayah Department of Ophthalmology, Cairo University, Giza, Egypt Purpose: The purpose of this study is to compare the efficacy of intratunnel cross-linking combined with intrastromal corneal ring segment (ICRS) implantation versus combined epithelium-off (epi-off) cross-linking and ICRS implantation for the management of keratoconus.Methods: Our study included 20 eyes of 12 patients with moderate-to-severe keratoconus. Group A included 10 eyes that underwent simultaneous ICRS implantation with intratunnel cross-linking. Group B included 10 eyes that underwent simultaneous ICRS implantation with epi-off cross-linking. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest sphere and
DISCUSSION. Over the last few years, the impact of higher order aberrations on visual development and emmetropization has been the source of much debate. Brunette et al. described significant levels of higher order aberrations in children, but these higher order aberrations tended to decrease with growth, possibly as part of emmetropization(8). Studies have shown that lower order aberrations are responsible for about 90% of the quality of retinal images and that the remaining 10% is a combination of the effects of various higher order aberrations(9). However, higher order aberrations do not interact with each other in a linear algebraic manner(10,11); in fact, the effects of the different aberrations tend to compensate for each other(4,12). According to the work of Kelly et al., corneal optical aberrations are often compensated by internal ocular aberrations; therefore, the measurement of corneal wavefront aberrometry alone may produce inaccurate information about the retinal image quality(12). ...
Purpose: To assess reproducibility of central corneal thickness (CCT) measurement by means of ultrasonic pachymetry.. Methods: Fifty one volunteers underwent three sessions of CCT measurements, each consisting of three CCT measurements, performed by each of three different observers. Intra- and interobserver reproducibility was calculated by means of intraclass correlation coefficient (ICC). The expected range of variability between two independent evaluations was calculated using scatter plots of each test-retest difference against their mean. The standard deviation of the mean differences in the test-retest scores was used to describe the differences in the score spread.. Results: The ICC ranges of the intra- and interobserver evaluations were 0.95-0.97 and 0.89-0.95 respectively; the expected variability was ⩽±1% and ⩽± 2% respectively (95% confidence interval).. Conclusions: The measurement of CCT by means of ultrasonic pachymetry is highly reproducible.. ...
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Astigmatism is a common condition in which the cornea of the eye has a shape similar to that of a football, rather than a normal corneal shape resembling a baseball. Because the cornea is oddly shaped, light bends unequally as it enters the eye, causing vision distortion or blurriness.. Many who suffer from astigmatism do not know that it can often be corrected with LASIK eye surgery. Laser-assisted in situ keratomileusis (LASIK) is a popular form of laser eye surgery that reshapes the inner layer of the cornea to correct myopia, hyperopia and astigmatism. LASIK eye surgery has proven to be an effective treatment for many patients with mild or moderate astigmatism. LASIK is also a convenient option for many other people, even if they dont have astigmatism.. LASIK for astigmatism is accomplished by smoothing out the irregularities of the cornea at the precise points of the astigmatism, therefore allowing light to focus correctly on the retina. During the LASIK procedure in Buffalo, pulses of ...
Patients with myopia, hyperopia and astigmatism can now reduce or eliminate their dependence on contact lenses and eyeglasses through refractive surgery that includes radial keratotomy (RK), photorefractive keratectomy (PRK), laser-assisted in situ keratomileusis (LASIK), laser thermal keratoplasty (LTK) and intrastromal corneal rings (ICR). Since the approval of the excimer laser in 1995, the popularity of RK has declined because of the superior outcomes from PRK and LASIK. In patients with low-to-moderate myopia, PRK produces stable and predictable results with an excellent safety profile. LASIK is also efficacious, predictable and safe, with the additional advantages of rapid vision recovery and minimal pain. LASIK has rapidly become the most widely performed refractive surgery, with high patient and surgeon satisfaction. Noncontact Holium: YAG LTK provides satisfactory correction in patients with low hyperopia. ICR offers patients with low myopia the potential advantage of removal if the vision
Get information, facts, and pictures about Photorefractive keratectomy at Encyclopedia.com. Make research projects and school reports about Photorefractive keratectomy easy with credible articles from our FREE, online encyclopedia and dictionary.
The Weill Cornell Medicine Corneal, Cataract & Refractive Surgery Ophthalmology Fellowship offers two one-year positions which commence on July 7 of each academic year. Our dynamic, seven-member corneal faculty team provides fellows with comprehensive, hands-on, advanced training in corneal, cataract and laser refractive surgery. Fellows are expected to participate in the
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 ...
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- ...
... 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 ...
The gold standard diagnostic test for PMD is corneal topography.[2] However, it may not as specific as corneal pachymetry, ... Corneal collagen cross-linking[edit]. Main article: Corneal collagen cross-linking. There is evidence suggesting corneal ... if corneal topography is used for diagnosis, it should be in conjunction with clinical findings of peripheral, inferior corneal ... PMD lacks apical corneal scarring, Rizutti's phenomenon, Munson's sign, and the central corneal thickness is usually normal.[2] ...
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 ...
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 ...
Corneal and Retinal Topography: computerized tests that maps the surface of the retina, or the curvature of the cornea. ...
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 ...
... 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. ...
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 ...
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. As it is associated with excessive sun or ... "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 ...
Combined corneal topography and corneal wavefront data in the treatment of corneal irregularity and refractive error in LASIK ... Is topography-guided ablation profile centered on the corneal vertex better than wavefront-guided ablation profile centered on ... Stromal surface topography-guided custom ablation as a repair tool for corneal irregular astigmatism. Journal of Refractive ... Corneal pachymetric topography. Ophthalmology. 1994 Mar;101(3):432-438. Dan Z. Reinstein, Ronald H. Silverman, Stephen L. ...
Rabinowitz, YS; McDonnell, PJ (1989). "Computer-assisted corneal topography in keratoconus". Refractive & corneal surgery. 5 (6 ... Treatment options include contact lenses, intrastromal corneal ring segments, corneal collagen cross-linking, or corneal ... 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 ...
... corneal structure due to its characteristics and in particular its transparency allows differentiation by corneal topography of ...
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 ...
... 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- ...
In ophthalmology, corneal topography is used as a technique for mapping the surface curvature of the cornea. In tissue ... In human anatomy, topography is superficial human anatomy. In mathematics the concept of topography is used to indicate the ... The older sense of topography as the study of place still has currency in Europe. Topography in a narrow sense involves the ... Geomorphology Global Relief Model Hypsography Marine topography Topographic map What is topography? - Center for Geographic ...
Corneal topography. *Eye disease. *List of keratins expressed in the human integumentary system ...
Corneal topography. *Optical coherence tomography. *Electrodiagnosis: Electrooculography. *Electroretinography. * ...
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. *Electrodiagnosis: Electrooculography. *Electroretinography. * ...
NIDEK OPD Scan ARK10000 Corneal Topography Wavefront Autorefraction Keratometry. $3,300.00 or Best Offer 24d 18h ... Zeiss Humphrey Atlas 995 Corneal Topography System. $4,000.00 or Best Offer 7d 20h ... Zeiss ATLAS 992 Corneal Topographer (w/ printer, keyboard). $3,995.00 Buy It Now 22d 17h ... TOMEY TMS-4 CORNEAL TOPOGRAPHER Topographic modeling system.. $6,300.00 or Best Offer 1d 14h ...
... this presentation helps identify and interpret corneal topographies in patients scheduled for cataract surgery and demonstr ... Led by a team of topography experts, this presentation helps identify and interpret corneal topographies in patients scheduled ... Led by a team of topography experts, ... Evaluating Corneal Topography in Patients Slated for Cataract ...
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: ...
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 ...
... 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 ...
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 ...
... 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 becomes a crucial step in determining the correct lens parameters for our patients. Corneal mapping allows ... You are at:Home»Product News»Closeup»FITTING ORTHO-K WITH CORNEAL TOPOGRAPHY ... Using corneal mapping to look at the distribution of power becomes important when fitting patients for myopia control. The ... In our practice, we use the E300 Corneal Topographer from Medmont (and distributed in the United States by Nidek, Inc). The ...
Conductive Keratoplasty for Changing Corneal Curvature 11. Corneal Topography in Cataract Surgery. Amar Agarwal is the pioneer ... 17 Responses to Jaypee Gold Standard Mini Atlas Series Corneal Topography * raisogli. says: ... Jaypee Gold Standard Mini Atlas Series Corneal Topography. Posted on November 3, 2012. by dramroo ... can i ask u afavour, i need that book…corneal topography in clinical practice ...
The topography of your cornea is commonly taken by a computer assisted diagnostic tool. This tool takes a three dimensional ... Corneal Topography. Submitted by Karen Saland on Sun 12/30/2018 - 04:19. Corneal topography is a computer assisted diagnostic ... Corneal topography can be beneficial in the evaluation of certain diseases and injuries of the cornea including:. *Corneal ... the corneal topography map is used in conjunction with other tests to determine exactly how much corneal tissue will be removed ...
... to restore vision impaired by corneal disease, scarring, trauma, or infection. ... Duke corneal surgeons perform corneal transplant surgery (keratoplasty) ... Corneal Topography and Tomography. A computer-guided device creates a 3-D image map of your cornea to measure corneal power, ... Choosing a Corneal Transplant Surgeon. Advanced Training in Corneal Disease Management Our corneal surgeons are ...
Corneal Topography of Keratoconus. Wilson, Steven E.; Lin, David T.C.; Klyce, Stephen D. ... Corneal Graft Survival in HLA-A- and HLA-B-Matched Transplantations in High-Risk Cases with Retrospective Review of HLA-DR ... Human Corneal Storage in Modified McCarey-Kaufman and K-Sol Media: Effect on Endothelial Na+/K+ATPase Pump Site Density and ... Corneal Perforation in a Patient with Cockaynes Syndrome. Yamaguchi, Katsuhiro; Okabe, Hitoshi; Tamai, Makoto ...
By incorporating full corneal topography and wavefront analysis of the cornea the ALADDIN addresses the limitations of ...
Trusted Corneal Topography Specialist serving Nye County Pahrump, NV. Contact us at 775-234-5556 or visit us at 2120 East ... Corneal Topography Q & A. G. DENNIS LEAKS, OD LTD What is corneal topography?. Your cornea is the clear covering thats located ... Corneal Topography Corneal topography provides a detailed "map" of your cornea thats important for contact lens fitting, laser ... What happens during corneal topography?. Corneal topography is completely painless and noninvasive, and it takes about five ...
  • Aetna considers repeat ultrasound corneal pachymetry for corneal diseases and injuries (indications D through I) not medically necessary if performed more frequently than once every 6 months. (aetna.com)
  • Aetna considers corneal pachymetry to be of no proven value in the work-up of persons prior to cataract surgery unless corneal disease is documented. (aetna.com)
  • Aetna considers corneal pachymetry experimental and investigational for the following indications (not an all-inclusive list) because its effectiveness for these indications has not been established. (aetna.com)
  • For purposes of this policy, only the ultrasound method of corneal pachymetry is considered. (aetna.com)
  • However, the conclusions of OHTS are limited to persons with ocular hypertension (greater than 24 mm Hg), and do not establish the value of corneal pachymetry for screening persons without ocular hypertension. (aetna.com)
  • In addition, there are no prospective clinical outcome studies demonstrating the clinical utility of corneal pachymetry in selecting patients for therapy, for guiding therapy and improving clinical outcomes. (aetna.com)
  • Corneal pachymetry may be useful in assessing candidates for penetrating keratoplasty (corneal transplant), and assessing graft failure and the need for regrafting in corneal transplant recipients by aiding in the early diagnosis and treatment of graft rejection. (aetna.com)
  • 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)
  • Review 8+ years of Clinical experience of surgical management of Keratoconus and other ectatic diseases using Topography Guided PRK + Corneal Crosslinking. (wcea.education)
  • on the other hand, improving the corneal shape could help the IOL estimation [ 14 ]. (hindawi.com)
  • During my annual contact lens exam, my doctor charges an extra fee for corneal topography. (verywellhealth.com)
  • 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. (shattky.co.nz)
  • Corneal mapping allows us to evaluate important corneal characteristics necessary for an optimal contact lens fit. (optometricoffice.com)
  • Fungal keratitis is of growing concern amongst contact lens wearers, and is a serious and painful corneal disease caused by a fungal organism. (newsightlasikcenter.com)
  • Microbiological findings and predisposing risk factors in corneal ulcers. (nih.gov)
  • 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)
  • They introduced a two-step procedure with CXL performed first and topography-guided PRK after a 1-year interval [ 2 ]. (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)
  • 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)
  • Immediately before the procedure, the ophthalmologist may request corneal topography (a corneal map) to compare with previous maps to ensure the treatment plan is still correct. (encyclopedia.com)
  • A combined procedure, instrastromal corneal ring segments (ICRS) implantation followed by cataract surgery with IOL implantation, has also been proposed [ 14 , 15 ]. (hindawi.com)
  • Since then, Daniel Durrie, MD, and Stephen Slade, MD, have developed sub-Bowman's keratomileusis (SBK), a procedure that uses the Intralase FS femtosecond laser (Advanced Medical Optics, Inc., Santa Ana, CA) to customize the parameters of the corneal flap for individual patients. (crstoday.com)
  • 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)
  • 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)
  • 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)
  • Characteristics of ocular higher-order aberrations in patients with pellucid marginal corneal degeneration. (medscape.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)
  • 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)
  • Thirty-seven patients (50 eyes) with progressive keratoconus planned for corneal crosslinking were included. (bmj.com)
  • Corneal topography becomes a crucial step in determining the correct lens parameters for our patients. (optometricoffice.com)
  • To investigate two new stiffness parameters and their relationships with the dynamic corneal response (DCR) parameters and compare normal and keratoconic eyes. (nih.gov)
  • Stiffness parameters are defined as Resultant Pressure at inward applanation (A1) divided by corneal displacement. (nih.gov)
  • Comparison of Corneal Deformation Parameters in Keratoconic and Normal Eyes Using a Non-contact Tonometer With a Dynamic Ultra-High-Speed Scheimpflug Camera. (nih.gov)
  • The first article to compare Dr. Stulting's original cases with control eyes that did not become ectatic after LASIK also confirmed that patients whose topographies showed signs of forme fruste keratoconus had an increased risk of developing ectasia after LASIK. (crstoday.com)
  • Led by a team of topography experts, this presentation helps identify and interpret corneal topographies in patients scheduled for cataract surgery and demonstrates how the information helps optimize treatment plans. (aao.org)
  • Forty-three eyes of 22 patients who underwent topography-guided FS-LASIK for myopic correction were included. (healio.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)
  • 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)
  • Using corneal mapping to look at the distribution of power becomes important when fitting patients for myopia control. (optometricoffice.com)
  • 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)
  • 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)
  • 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)
  • The first fully automated corneal topographer was called Corneal Modeling System (CMS-1), developed by Computed Anatomy Inc. (New York, USA). (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)
  • Qualitative analysis selected 10 EyeSys and 15 Pentacam topographies used in the quantitative evaluation. (scielo.br)
  • 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 main problem for these IOLs is that the corneal irregularities are still present after IOL implantation, and it could restrict the visual rehabilitation. (hindawi.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)
  • 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)
  • The usual measurements are corneal, white to white,and axial length. (rockymountaineye.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)