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)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)Lasers: An optical source that emits photons in a coherent beam. Light Amplification by Stimulated Emission of Radiation (LASER) is brought about using devices that transform light of varying frequencies into a single intense, nearly nondivergent beam of monochromatic radiation. Lasers operate in the infrared, visible, ultraviolet, or X-ray regions of the spectrum.Hyperopia: A refractive error in which rays of light entering the eye parallel to the optic axis are brought to a focus behind the retina, as a result of the eyeball being too short from front to back. It is also called farsightedness because the near point is more distant than it is in emmetropia with an equal amplitude of accommodation. (Dorland, 27th ed)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.Refraction, Ocular: Refraction of LIGHT effected by the media of the EYE.Eye: The organ of sight constituting a pair of globular organs made up of a three-layered roughly spherical structure specialized for receiving and responding to light.Keratectomy, Subepithelial, Laser-Assisted: A surgical technique to correct REFRACTIVE ERRORS of the EYE, such as MYOPIA and ASTIGMATISM. In this method, a flap of CORNEAL EPITHELIUM is created by exposure of the area to dilute alcohol. The flap is lifted and then replaced after laser ablation of the subepithelial CORNEA.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.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)Refractive Errors: Deviations from the average or standard indices of refraction of the eye through its dioptric or refractive apparatus.Morning Sickness: Symptoms of NAUSEA and VOMITING in pregnant women that usually occur in the morning during the first 2 to 3 months of PREGNANCY. Severe persistent vomiting during pregnancy is called HYPEREMESIS GRAVIDARUM.Physician Assistants: Health professionals who practice medicine as members of a team with their supervising physicians. They deliver a broad range of medical and surgical services to diverse populations in rural and urban settings. Duties may include physical exams, diagnosis and treatment of disease, interpretation of tests, assist in surgery, and prescribe medications. (from http://www.aapa.orglabout-pas accessed 2114/2011)Nurse Practitioners: Nurses who are specially trained to assume an expanded role in providing medical care under the supervision of a physician.Family Practice: A medical specialty concerned with the provision of continuing, comprehensive primary health care for the entire family.France: A country in western Europe bordered by the Atlantic Ocean, the English Channel, the Mediterranean Sea, and the countries of Belgium, Germany, Italy, Spain, Switzerland, the principalities of Andorra and Monaco, and by the duchy of Luxembourg. Its capital is Paris.Orthokeratologic Procedures: An alternative to REFRACTIVE SURGICAL PROCEDURES. A therapeutic procedure for correcting REFRACTIVE ERRORS. It involves wearing CONTACT LENSES designed to force corrective changes to the curvature of the CORNEA that remain after the lenses are removed. The effect is temporary but is maintained by wearing the therapeutic lenses daily, usually during sleep.Eyeglasses: A pair of ophthalmic lenses in a frame or mounting which is supported by the nose and ears. The purpose is to aid or improve vision. It does not include goggles or nonprescription sun glasses for which EYE PROTECTIVE DEVICES is available.Williams Syndrome: A disorder caused by hemizygous microdeletion of about 28 genes on chromosome 7q11.23, including the ELASTIN gene. Clinical manifestations include SUPRAVALVULAR AORTIC STENOSIS; MENTAL RETARDATION; elfin facies; impaired visuospatial constructive abilities; and transient HYPERCALCEMIA in infancy. The condition affects both sexes, with onset at birth or in early infancy.Air Pollution: The presence of contaminants or pollutant substances in the air (AIR POLLUTANTS) that interfere with human health or welfare, or produce other harmful environmental effects. The substances may include GASES; PARTICULATE MATTER; or volatile ORGANIC CHEMICALS.Molteno Implants: Devices implanted to control intraocular pressure by allowing aqueous fluid to drain from the anterior chamber. (Hoffman, Pocket Glossary of Ophthalmologic Terminology, 1989)Hydrophthalmos: Congenital open-angle glaucoma that results from dysgenesis of the angle structures accompanied by increased intraocular pressure and enlargement of the eye. Treatment is both medical and surgical.Glaucoma: An ocular disease, occurring in many forms, having as its primary characteristics an unstable or a sustained increase in the intraocular pressure which the eye cannot withstand without damage to its structure or impairment of its function. The consequences of the increased pressure may be manifested in a variety of symptoms, depending upon type and severity, such as excavation of the optic disk, hardness of the eyeball, corneal anesthesia, reduced visual acuity, seeing of colored halos around lights, disturbed dark adaptation, visual field defects, and headaches. (Dictionary of Visual Science, 4th ed)Lenses, Intraocular: Artificial implanted lenses.Biometry: The use of statistical and mathematical methods to analyze biological observations and phenomena.Immersion: The placing of a body or a part thereof into a liquid.Axial Length, Eye: The distance between the anterior and posterior poles of the eye, measured either by ULTRASONOGRAPHY or by partial coherence interferometry.Tupaiidae: The only family of the order SCANDENTIA, variously included in the order Insectivora or in the order Primates, and often in the order Microscelidea, consisting of five genera. They are TUPAIA, Ananthana (Indian tree shrew), Dendrogale (small smooth-tailed tree shrew), Urogale (Mindanao tree shrew), and Ptilocercus (pen-tailed tree shrew). The tree shrews inhabit the forest areas of eastern Asia from India and southwestern China to Borneo and the Philippines.ShrewsSclera: The white, opaque, fibrous, outer tunic of the eyeball, covering it entirely excepting the segment covered anteriorly by the cornea. It is essentially avascular but contains apertures for vessels, lymphatics, and nerves. It receives the tendons of insertion of the extraocular muscles and at the corneoscleral junction contains the canal of Schlemm. (From Cline et al., Dictionary of Visual Science, 4th ed)Tupaia: A genus of tree shrews of the family TUPAIIDAE which consists of about 12 species. One of the most frequently encountered species is T. glis. Members of this genus inhabit rain forests and secondary growth areas in southeast Asia.Anterior Chamber: The space in the eye, filled with aqueous humor, bounded anteriorly by the cornea and a small portion of the sclera and posteriorly by a small portion of the ciliary body, the iris, and that part of the crystalline lens which presents through the pupil. (Cline et al., Dictionary of Visual Science, 4th ed, p109)Pigment Epithelium of Eye: The layer of pigment-containing epithelial cells in the RETINA; the CILIARY BODY; and the IRIS in the eye.Choroid: The thin, highly vascular membrane covering most of the posterior of the eye between the RETINA and SCLERA.Chickens: Common name for the species Gallus gallus, the domestic fowl, in the family Phasianidae, order GALLIFORMES. It is descended from the red jungle fowl of SOUTHEAST ASIA.Retinal Pigment Epithelium: The single layer of pigment-containing epithelial cells in the RETINA, situated closely to the tips (outer segments) of the RETINAL PHOTORECEPTOR CELLS. These epithelial cells are macroglia that perform essential functions for the photoreceptor cells, such as in nutrient transport, phagocytosis of the shed photoreceptor membranes, and ensuring retinal attachment.Proprotein Convertases: Proteolytic enzymes that are involved in the conversion of protein precursors such as peptide prohormones into PEPTIDE HORMONES. Some are ENDOPEPTIDASES, some are EXOPEPTIDASES.Glycosylation: The chemical or biochemical addition of carbohydrate or glycosyl groups to other chemicals, especially peptides or proteins. Glycosyl transferases are used in this biochemical reaction.Chick Embryo: The developmental entity of a fertilized chicken egg (ZYGOTE). The developmental process begins about 24 h before the egg is laid at the BLASTODISC, a small whitish spot on the surface of the EGG YOLK. After 21 days of incubation, the embryo is fully developed before hatching.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.Ophthalmologic Surgical Procedures: Surgery performed on the eye or any of its parts.Cataract Extraction: The removal of a cataractous CRYSTALLINE LENS from the eye.Color: The visually perceived property of objects created by absorption or reflection of specific wavelengths of light.Cataract: Partial or complete opacity on or in the lens or capsule of one or both eyes, impairing vision or causing blindness. The many kinds of cataract are classified by their morphology (size, shape, location) or etiology (cause and time of occurrence). (Dorland, 27th ed)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.Aniseikonia: A condition in which the ocular image of an object as seen by one eye differs in size and shape from that seen by the other.Accommodation, Ocular: The dioptric adjustment of the EYE (to attain maximal sharpness of retinal imagery for an object of regard) referring to the ability, to the mechanism, or to the process. Ocular accommodation is the effecting of refractive changes by changes in the shape of the CRYSTALLINE LENS. Loosely, it refers to ocular adjustments for VISION, OCULAR at various distances. (Cline et al., Dictionary of Visual Science, 4th ed)Lens Implantation, Intraocular: Insertion of an artificial lens to replace the natural CRYSTALLINE LENS after CATARACT EXTRACTION or to supplement the natural lens which is left in place.Lens Capsule, Crystalline: The thin noncellular outer covering of the CRYSTALLINE LENS composed mainly of COLLAGEN TYPE IV and GLYCOSAMINOGLYCANS. It is secreted by the embryonic anterior and posterior epithelium. The embryonic posterior epithelium later disappears.Lens, Crystalline: A transparent, biconvex structure of the EYE, enclosed in a capsule and situated behind the IRIS and in front of the vitreous humor (VITREOUS BODY). It is slightly overlapped at its margin by the ciliary processes. Adaptation by the CILIARY BODY is crucial for OCULAR ACCOMMODATION.

*Near-sightedness

... whereby the eye alters its growth to effectively eliminate the lens induced blur. Anatomically, the changes in axial length of ... Strongly near-sighted wearers of contact lenses do not experience these distortions because the lens moves with the cornea, ... There is evidence that lack of normal visual stimuli causes improper development of the eyeball. In this case, "normal" refers ... Hyperopia, the biological opposite of myopia, may also be used metaphorically for a value system or motivation that exhibits " ...

*Emmetropia

This condition of the normal eye is achieved when the refractive power of the cornea and the axial length of the eye balance ... visual acuity roughly half normal). A person with exceptionally acute vision (excellent cornea and lens and better than ... 2000). "Normal emmetropization in infants with spectacle correction for hyperopia". Invest Ophthalmol Vis Sci. 41 (12): 3726- ... By shaping the cornea, emmetropic vision can be achieved without corrective lenses. The correction for only emmetropic vision ...
Abstract: : Purpose:Astigmatism is a major problem after penetrating keratoplasty. The aims of this investigation were to determine whether there is a relation between preoperative diagnosis and postoperative astigmatism, and to investigate the benefit of relaxing incisions. Methods:Approximately 90% of the corneal transplants performed in Sweden since 1996 have been reported to the Swedish Cornea Transplant Register. Preoperative and 2-year postoperative data were collected. Astigmatism was measured in 844 patients after suture removal. In 81 of the patients relaxing incisions were used to decrease the postoperative astigmatism. The data were analysed by multiple regression methods. Results:The overall mean astigmatism was 4.6 D (95% CI 4.4 to 4.8) with 33% of the grafts having ,3 D of astigmatism. Multiple regression analysis after square root transformation of astigmatism showed no differences between different diagnostic groups although there was a slight increase in ...
Abstract: : Purpose: To investigate whether the human amniotic membrane can decrease the induced astigmatism of laser corneal refractive surgery. Methods: PARK (-3D of astigmatism 1800) was performed on both eyes of 10 albino rabbits, which were divided into 2 groups, each 10 eyes. Immediate after PARK, group A received amniotic membrane graft and group B received polyethylen film graft on cornea. The degree of astigmatism was measured with topography and cycloplegic refraction at preoperative and 4, 8, 12 weeks postoperatively and evaluated by vector analysis. Results: Topography data showed that mean preoperative average keratometry and corneal astigmatism had no significant difference in both groups. After 3 months, mean change of the corneal astigmatism was 1.440.86D in the group A, compared with 2.590.30D in the group B. This change of astigmatism showed significant difference, as well as the axis of astigmatism (p,0.05). The surgically ...
Astigmatism is usually detected through a routine eye exam. In the same manner that myopia and hyperopia are diagnosed, astigmatism is discovered with the same techniques and instruments. An estimation of the amount of astigmatism is performed via a retinoscopy, where light is directed into the eye while using a series of lenses.. Once astigmatism is diagnosed as the cause of vision problems, one of the following options can be pursued to provide treatment:. Corrective Lenses are the most common method to address astigmatism. Like far and nearsightedness, your optometrist can prescribe a lens shape that corrects for astigmatism.. Contact Lenses correct for visual irregularities in a similar manner that glasses do. A hard lens is used unlike soft contact lenses that some people are accustomed to. Lenses that correct for astigmatism require a long adaptation period so the ...
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, ...
Looking for online definition of simple astigmatism in the Medical Dictionary? simple astigmatism explanation free. What is simple astigmatism? Meaning of simple astigmatism medical term. What does simple astigmatism mean?
Laser correction for myopia and astigmatism using an excimer laser has been performed with success for several years.. During the last 2 years, a new method for correction of refractive errors has emerged. In the method (ReLex) a femtosecond laser is used to cut a lenticule in the corneal stroma that is subsequently removed. For simple myopia this method has proved effective and on par with excimer baser LASIK. However, it remains to be determined if ReLEx is as effective in the treatment of astigmatism.. In the study, patients with high astigmatism are treated with conventional LASIK for astigmatism in one eye and with ReLEx for astigmatism in the other. ...
Astigmatism Astigmatism app is your best choice if you want to know all about Astigmatism. Working all day in front of the computer? Are your eyes getting tired? Do you have myopia, hyperopia or astigmatism? Wor...
There are no real exercises that can help astigmatism, and it should be treated with glasses, contacts or LASIK. Discover why exercises cant help astigmatism with tips from an optometrist in this free video on human eye problems and disorders. Expert: Dr. James W. Kirkconnell Contact: www.bec2020.com Bio: Dr. James W. Kirkconnell graduated from the University of Houston College of Optometry in 1984. Filmmaker: Dimitri LaBarge. Tags: Astigmatism, College Of Optometry, Dimitri, Discover, Dr James, Exercises, Exercises For Astigmatism, Eye Problems, Filmmaker, Glasses, Houston College Of Optometry, Human Eye, Kirkconnell, Labarge, LASIK, Optometrist, University Of Houston, University Of Houston College Of Optometry ...
Eye practices are valuable in rectifying an assortment of vision issues. These eye practice methods can redress vision conditions, for example, partial blindness and farsightedness. Eye activities can likewise remedy another vision condition called Astigmatism. Astigmatism is characterized as an eye condition whereby your vision is foggy at any separation. A portion of the reasons for astigmatism incorporates sporadically formed ebb and flow has the cornea or eye focal point. You can read at cloud chasers for other Astigmatism causes incorporate eye damage, and complications related with eye surgery.. High glucose levels and issues related with diabetes are likewise contributing components to this vision condition as to diabetes. Such an issue can prompt the development of an abnormally formed eye focal point. This is related with a condition called Lenticular Astigmatism. The most ideal approach to rectify this issue is to bring glucose levels once more into the ordinary ...
This page provides relevant content and local businesses that can help with your search for information on Astigmatism Treatment. You will find informative articles about Astigmatism Treatment, including Astigmatism Symptoms And Treatment. Below you will also find local businesses that may provide the products or services you are looking for. Please scroll down to find the local resources in Cheyenne, WY that can help answer your questions about Astigmatism Treatment.
This page provides relevant content and local businesses that can help with your search for information on Astigmatism Treatment. You will find informative articles about Astigmatism Treatment, including Astigmatism Symptoms And Treatment. Below you will also find local businesses that may provide the products or services you are looking for. Please scroll down to find the local resources in Lebanon, OR that can help answer your questions about Astigmatism Treatment.
Purpose: : To investigate human cornea proteome. The human cornea is composed of several layers interacting in a complex manner and possessing specific functions, like eye protection and optical clearness. Only few proteomic studies of mammalian cornea have been performed leading to the identification of less than 200 proteins in human corneas. Methods: : The present study explores the proteome of the intact normal human cornea using a shot-gun nanoLC-MS/MS strategy and an LTQ Orbitrap mass spectrometer. Results: : A total of 2070 distinct corneal proteins were identified from five human cornea samples, which represents a 14-fold improvement in the number of proteins identified so far for human cornea. Network and gene ontology analyses were used to determine biological pathways specific of the human cornea. They allowed the identification ...
Purpose : The cornea efficiently restricts permeability of topically administered drugs into the eye. Currently, permeability of drug candidates is tested across excised animal corneas ex vivo or using in vitro cell culture models. The purpose of this study was to develop an artificial cornea for drug permeability screening in early drug development that more adequately resembles the human cornea. Methods : Several modifications of artificial corneas were prepared using different hydrogel cross-linking and coating techniques. The apparent permeability coefficient (Papp) values of standard reference molecules across artificial corneas were tested using Navicyte vertical diffusion chambers. Permeability characteristics (tightness, dynamic range) of the artificial cornea was assessed, and the Papp values across artificial cornea were correlated with those of ex vivo rabbit ...
Astigmatic subjects are adapted to their astigmatism and perceptually recalibrate on its correction. However, whether perceptual changes parallel changes in visual acuity is unknown. Visual acuity was measured during a 6-month period in nonastigmats, corrected astigmats, and uncorrected astigmats (who were given spectacles after the first session) under induction of astigmatism at different axis while controlling aberrations. Induction of astigmatism decreases visual performance and is axis dependent. It was better for astigmatism induced at 90 degrees in nonastigmats and at their natural axis in astigmats. This suggests that astigmats may store adaptation states/cues related to their natural astigmatism. (p. 1430). ...
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PURPOSE OF REVIEW:. Artificial corneas are being developed to meet a shortage of donor corneas and to address cases in which allografting is contraindicated. A range of artificial corneas has been developed. Here we review several newer designs and especially those inspired by naturally occurring biomaterials found with the human body and elsewhere.. RECENT FINDINGS:. Recent trends in the development of artificial corneas indicate a move towards the use of materials derived from native sources including decellularized corneal tissue and tissue substitutes synthesized by corneal cells in vitro when grown either on their own or in conjunction with novel protein-based scaffolds. Biologically inspired materials are also being considered for implantation on their own with the view to promoting endogenous corneal tissue.. SUMMARY:. More recent attempts at making artificial corneas ...
Spherical Contact Lenses: A regular soft contact lens will correct, or mask, up to .50 diopters of cylinder corneal astigmatism. Above .50 dioptersthe soft lens will be distorted and vision will be blurred. A gas-permeable contact lens, however, can correct up to 3.00 diopters of corneal astigmatism ...
Full thickness corneal transplant. Your entire cornea may need to be replaced if both the front and inner corneal layers are damaged. This is called penetrating keratoplasty (PK), or full thickness corneal transplant. Your diseased or damaged cornea is removed. Then the clear donor cornea is sewn into place.. PK has a longer recovery period than other types of corneal transplants. Getting complete vision back after PK may take up to 1 year or longer.. With a PK, there is a slightly higher risk than with other types of corneal transplants that the cornea will be rejected. This is when the bodys immune system attacks the new cornea tissue.. Partial thickness corneal transplant. Sometimes the front and middle layers of the cornea are damaged. In this case, only those layers are removed. The endothelial layer, ...
This article described the new Trulign toric intraocular lens implant for patients with astigmatism undergoing cataract surgery in our state-of-the-art surgical center (ASC) in Millville New Jersey.
The corneas of people with glaucoma seem to exhibit different qualities than those who do not suffer from this condition.. A French study determines that corneas of patients with glaucoma are more likely to be less elastic and lose their proper shape than healthy corneas. The researchers assessed the condition of almost 500 eyes with and without glaucoma and found that the eyes of patients with glaucoma tended to have a higher corneal resistance factor (CRF) and lower corneal hysteresis (CH) - both signs of poor corneal biomechanics.. Corneal resistance refers to the flexibility or none flexibility of the cornea - a higher factor means that the cornea is less flexible. I higher factor means that the cornea is less flexible.. Corneal hysteresis refers to the ability of the cells comprising the cornea to to ...
The refractive surgery team uses precision laser eye surgery techniques and specialised lens implants to correct focusing problems such as short sight (myopia), long sight (hypermetropia), irregular focus (astigmatism) and loss of reading vision (presbyopia). A refractive error, for example, partial blindness (near sightedness), farsightedness (hyperopia), astigmatism or presbyopia, refractive surgery is a strategy for revising or enhancing vision. There are different surgical methods for modifying eyes centering capacity by reshaping the cornea, or clear, round vault at the front of your eye. Different techniques include embedding a focal point inside the eye. The most generally performed kind of refractive surgery is LASIK (laser-aided situ keratomileusis), where a laser is utilized to reshape the cornea. For individuals who are myopic, certain refractive surgery systems will diminish the bend of a cornea that is ...
Cataracts and irregular corneal astigmatism are conditions that are often encountered simultaneously by eye care providers. Conditions such as Salzmann nodular degeneration, pterygium, epithelial basement membrane dystrophy (EBMD), keratoconus... Full Story →. ...
Welcome to the Lens Mart Local Pages. Here you will find local resources about Acuvue For Astigmatism in Chapel Hill, NC and some related products that may be of interest to you. For your convenience, we have also compiled a list of businesses and services around Chapel Hill, including Eyeglass Stores, Optometrists, and Ophthalmologists that should help with your search. Before you take a look at the local resources, please browse through our competitively priced products that you could order from the comfort of your own home.
Welcome to the Lens Mart Local Pages. Here you will find local resources about Acuvue For Astigmatism in Sylvania, OH and some related products that may be of interest to you. For your convenience, we have also compiled a list of businesses and services around Sylvania, including Eyeglass Stores, Optometrists, and Ophthalmologists that should help with your search. Before you take a look at the local resources, please browse through our competitively priced products that you could order from the comfort of your own home.
Looking for online definition of Slit-Lamp Biomicroscopy in the Medical Dictionary? Slit-Lamp Biomicroscopy explanation free. What is Slit-Lamp Biomicroscopy? Meaning of Slit-Lamp Biomicroscopy medical term. What does Slit-Lamp Biomicroscopy mean?
This is a more recently developed procedure that involves only replacing the innermost layers of the cornea rather than the whole cornea as in penetrating keratoplasty. In conditions such as Fuchs endothelial dystrophy, the innermost layer called the endothelium is diseased. This results in swelling of the cornea causing decreased vision. Previously to replace the valuable endothelial layer the whole central cornea was replaced by performing a Penetrating Keratoplasty. With innovative techniques, we are now able to replace just the innermost layer.. The procedure involves peeling off the inner two layers of the diseased cornea. A donor cornea is then split or dissected to create a flap of the inner two layers and a small portion of stroma (to provide substance for manipulation). This 3 layer donor is then folded and inserted into the eye. It is then unfolded and lifted up against the patients ...
TY - JOUR. T1 - Monitoring of rabbit cornea response to dehydration stress by optical coherence tomography. AU - Hosseini, Kamran. AU - Kholodnykh, Alexander I.. AU - Petrova, Irina Y.. AU - Esenaliev, Rinat O.. AU - Hendrikse, Fred. AU - Motamedi, Massoud. PY - 2004/8/1. Y1 - 2004/8/1. N2 - PURPOSE. To evaluate the application of optical coherence tomography (OCT) for continuous noninvasive monitoring and quantification of the dynamics of corneal response after exposure of the cornea to dehydrating stress. METHODS. The changes in central corneal thickness (CCT) and scattering properties of the cornea were monitored with OCT in rabbit cornea in vivo after topical application of a glycerin-based hypertonic agent (HA) or prolonged surface evaporation of the cornea. The observed changes in backscatter were correlated with the changes in corneal hydration. RESULTS. An inverse ...
Lattice corneal dystrophy type I is an eye disorder that affects the clear, outer covering of the eye called the cornea. The cornea must remain clear for an individual to see properly; however, in lattice corneal dystrophy type I, protein clumps known as amyloid deposits cloud the cornea, which leads to vision impairment. The cornea is made up of several layers of tissue, and in lattice corneal dystrophy type I, the deposits form in the stromal layer. The amyloid deposits form as delicate, branching fibers that create a lattice pattern.. Affected individuals often have recurrent corneal erosions, which are caused by separation of particular layers of the cornea from one another. Corneal erosions are very painful and can cause sensitivity to bright light (photophobia). Lattice corneal dystrophy type I is usually bilateral, ...
The results from this research may open the door to future therapeutics for a myriad of corneal disorders. "It is essential to know the biochemical composition of normal healthy corneas in the effort to understand the molecular mechanisms behind corneal disorders," emphasizes Dr. Enghild. "By comparative proteomic studies of diseased and normal corneas we can identify differences in the expression profiles that may suggest avenues for therapeutic interventions. Because the cornea is so accessible, the potential for developing effective drugs for the treatment of corneal diseases is good. Furthermore, the work is likely to improve the clinical classifications of corneal diseases. Identification of the protein profile of the normal human cornea may also be very useful in the effort toward generating artificial ...
Journal of Refractive Surgery | ABSTRACTBACKGROUND: Excimer laser photorefractive keratectomy tor the correction of myopia is presently under investigation in the United States by the Food and Drug Administration (FDA). The Phase 1 1 -B FDA study is being conducted on 75 normally sighted myopic eyes utilizing three currently available excimer lasers. This report presents the 1 -year results on 12 myopic eyes treated with the
TY - JOUR. T1 - Athermal division and selective suture ligation of the dorsal vein complex during robot-assisted laparoscopic radical prostatectomy. T2 - Description of technique and outcomes. AU - Lei, Yin. AU - Alemozaffar, Mehrdad. AU - Williams, Stephen. AU - Hevelone, Nathanael. AU - Lipsitz, Stuart R.. AU - Plaster, Blakely A.. AU - Amarasekera, Channa A.. AU - Ulmer, William D.. AU - Huang, Andy C.. AU - Kowalczyk, Keith J.. AU - Hu, Jim C.. PY - 2011/2. Y1 - 2011/2. N2 - Background: Apical dissection and control of the dorsal vein complex (DVC) affects blood loss, apical positive margins, and urinary control during robot-assisted laparoscopic radical prostatectomy (RALP). Objective: To describe technique and outcomes for athermal DVC division followed by selective suture ligation (DVC-SSL) compared with DVC suture ligation followed by athermal division (SL-DVC). Design, settings, and participants: Retrospective study of prospectively collected data from February 2008 to July 2010 for 303 ...
PURPOSE: To investigate the association between corneal biomechanical properties measured with the Ocular Response Analyzer (ORA) and also CorvisST (CST) tonometry, and glaucomatous visual field (VF) severity. METHODS: One hundred forty-six eyes of 91 patients with primary open-angle glaucoma who performed Humphrey Field Analyzer 30-2 or 24-2 SITA-Standard, ORA, and CST within 180 days were included in this multicentral, observational cross-sectional study. The association between ORA parameters (corneal hysteresis [CH] and corneal resistant factor [CRF]), CST parameters (A1 and A2 time, A1 and A2 length, A1 and A2 velocity, A1 and A2 deformation amplitude, highest deformation amplitude, highest concavity time, peak distance, and radius), and other basic parameters (age, intraocular pressure with Goldmann applanation tonometry, central corneal thickness, and axial length) ...
3D printed spectacles for corrective vision. A keratoconus-affected cornea loses its natural roundness and bulges out to form a cone-like shape. The light entering the eye to the retina is deflected which is the cause of distorted vision. According to the Royal National Institute of Blind People (RNIB), keratoconus affects 1 in 2,000 people in Britain and is more common in South Asian people. Dr. Hongxin explained that a blueprint of a patients cornea can be used to fully customize the 3D printed spectacles to fit corneas of different shapes. This will correct the distortion of the eye-sight. "Normal corneas have a smooth and convex surface, while their [keratoconus patients] corneas are bumpy with many irregular concaves," Dr Hongxin told Beijing News. Inspired by NASA Dr. Hongxin says the 3D printed spectacles for cornea patients were inspired by NASAs adaptive optics technology (AO). NASA ...
TY - JOUR. T1 - Correlative transmission electron microscopy and scanning electron microscopy of rabbit cornea. AU - Fauziah, O.. AU - Siti-Saleha, M.. AU - Abd. Ghafar, Norzana. AU - Asmah, R.. AU - Aminuddin, S.. AU - Idrus, Ruszymah. PY - 2010. Y1 - 2010. N2 - The present work was carried out to study the organization of rabbit cornea. The transparent nature of the normal cornea was very important to give the understanding of the cornea in health and disease state. The ultrastructural features of the cornea were obtained by transmission electron microscopy and scanning electron microscopy. The epithelial surface of the cornea composed of microvilli and microplicae. In the Bowmans membrane, the individual collagen fibrils were interwoven densely to form a felt-like sheet, while in the stroma, the collagen fibrils ran abreast in lamellae. In the innermost stromal region adjacent to ...
C H A P T E R 1 4 Excimer Laser Photorefractive Keratectomy for Keratoconus Arun C. Gulani, MD; Lee T. Nordan, MD; Noel Alpins, FRANZCO, FRCOphth, FACS; and George Stamatelatos, BSCOptom P atients with
We evaluated the corneal biomechanical properties in a population of healthy children in China. As far as we know, this is the first report of quantitative assessment of the corneal biomechanics in children population using CST. We used the newly updated CST software, which provided two more parameters (A1DA and A2DA) than previous versions. This helped to measure corneal deformation more comprehensively. We also assessed the symmetry of corneal biomechanics between the both eyes and found obviously interocular symmetry in SE, CCT, IOP, and corneal biomechanics in healthy children eyes. We also found that several CST biomechanical parameters in children are modified by CCT and IOP, while age, SE, and sex exert little influence on the CST measurements in this population.. Our observations of interocular symmetric biometry were consistent with previous studies [19-21]. Using ORA, Zheng et al. [22] demonstrated an obvious ...
PURPOSE: To report the impact of posture-related ocular cyclotorsion on one surgeons surgically induced astigmatism (SIA) results and the variance in SIA. SETTING: Institute of Eye Surgery, Whitfield Clinic, Waterford, Ireland. METHODS: This prospective randomized controlled study included eyes that had phacoemulsification with intraocular lens implantation. Eyes were randomly assigned to have (intervention group) or not have (control group) correction for posture-related ocular cyclotorsion. In the intervention group, the clear corneal incision was placed precisely at the 120-degree meridian with instruments designed to correct posture-related ocular cyclotorsion. In the control group, the surgeon endeavored to place the incision at the 120-degree meridian, but without markings. RESULTS: The intervention group comprised 41 eyes and the control group, 61 eyes. The mean absolute SIA was 0.74 diopters (D) in the intervention group and 0.78 D in the control group; the ...
The traditional corneal transplant surgery involves removing the diseased or damaged tissue from you reye and replacing it with the healthy donor tissue. The entire operation is done under a surgical microscope. You will be asleep during the procedure and therefore will not feel any pain.. Most of the diseased cornea is removed surgically after using a circular blade (trephine) to cut into the cornea. This is then removed by using corneal micro-scissors. A similar procedure is performed on the donor cornea and the donor disc which is similar in size to the cornea that was removed is used to replace the patients cornea with healthy donor tissue. The donor cornea is held in place with very fine stitches using suture material that is usually thinner than the human hair.. The newer corneal transplant procedures only replace the diseased part of the ...
The cornea is the translucent part of the eye that covers the anterior portion of the eye. It covers the pupil, iris, and anterior chamber (fluid-filled inside of the eye). Its function is to refract, or bend, light. It is composed of proteins and cells. It does not contain blood vessels. Some of the blood vessels may cloud the cornea and prevent it from refracting light properly and adversely affect vision. The cornea inclines to repair itself quickly from minor abrasions but deeper abrasions may cause scars to form on the cornea that causes the cornea to lose its transparency, leading to visual impairment.. Cornea displaces depending on the disease that is causing vision problems. For example, Fuchs dystrophy only have a problem with the back layer of the cornea and require single cell layer from donor cornea in a procedure known as DMEK. Others conditions such as ...
Clinical applications of corneal confocal microscopy Mitra Tavakoli1, Parwez Hossain2, Rayaz A Malik11Division of Cardiovascular Medicine, University of Manchester and Manchester Royal Infirmary, Manchester, UK; 2University of Southampton, Southampton Eye Unit, Southampton General Hospital, Southampton, UKAbstract: Corneal confocal microscopy is a novel clinical technique for the study of corneal cellular structure. It provides images which are comparable to in-vitro histochemical techniques delineating corneal epithelium, Bowman’s layer, stroma, Descemet’s membrane and the corneal endothelium. Because, corneal confocal microscopy is a non invasive technique for in vivo imaging of the living cornea it has huge clinical potential to investigate numerous corneal diseases. Thus far it has been used in the detection and management of pathologic and infectious ...
Corneal Transplant Surgery. The cornea is the clear covering of the front of the eye which bends, or refracts, light rays as they enter the eye. For clear vision to occur, the cornea must have the correct shape and clarity to focus incoming light rays precisely on the retina at the back of the eye. When the cornea becomes cloudy or misshapen from injury, infection or disease, transplantation may be recommended to replace it.. Corneal transplants are usually performed with local anesthesia so there is no pain. During the procedure, the cornea is replaced with one from a human donor. The new cornea carries little risk of rejection and can last for many years.. DSEK Surgery. DSEK is the latest technique in corneal transplantation. Short for Descemet-stripping automated endothelial keratoplasty, DSEK offers clear post-operative vision and short recovery time to patients in need ...
PURPOSE. The authors investigated the phenotypic characteristics of basally located transitional cells in peripheral superior cornea, characterized previously by their coexpression of cytokeratin 19 and vimentin and their negativity for AE5. METHODS. Twenty adult human corneas were studied, using in situ immunohistochemical techniques and a panel of specific monoclonal antibodies against various surface and cytoplasmic molecules. RESULTS. The transitional cells shared staining characteristics with limbal basal cells in their expression of alpha 6 beta 4-integrin, metallothionein, AE1, and transferrin receptor. CONCLUSIONS. These transitional epithelial cells exhibit a unique phenotype differing from that of the surrounding basal epithelial cells in the peripheral cornea but analogous to that of limbal basal cells. These findings further corroborate the hypothesis that, at least from an immunohistochemical point of view, transitional cells in the superior ...
TY - JOUR. T1 - Quantitative assessment of anteroposterior keratocyte density in the normal rabbit cornea. AU - Petroll, W. M.. AU - Boettcher, K.. AU - Barry, P.. AU - Cavanagh, D.. AU - Jester, J. V.. PY - 1995. Y1 - 1995. N2 - The anteroposterior keratocyte density distribution in the rabbit cornea was measured. Unsectioned tissue blocks from the central cornea of five rabbits were stained with propidium iodide and imaged using a Leica laser scanning confocal microscope. A z-series of images was acquired in each sample, from anterior to posterior stroma in either 3- or 8-μm steps. Software was developed to allow interactive marking of the keratocyte nuclei within each section of the z-series and for calculating cell density. For convenience, cell density was expressed as the number of cells per corneal volume element (CVE), where CVE is a newly defined volume unit with x, y, and z dimensions of 250, 250, and 10 μm, ...
A clinical evaluation of a new electron ProTon tonometer was performed comparing the values of intraocular pressure (IOP) measured using this instrument with those determined by a similar instrument, Tono-Pen XL, and by Goldmann applanation tonometry. The mean IOP measured in 106 eyes with the ProTon tonometer was not significantly different from that determined with Goldmann applanation, while the IOP values measured with Tono-Pen XL were significantly lower. The 95% limits of agreement between applanation tonometry and ProTon tonometry were between -4 mm Hg and 5 mm Hg and between applanation tonometry and Tono-Pen XL tonometry between -3 mm Hg and 8 mm Hg. The ProTon tonometer appears to have a higher level of accuracy than the Tono-Pen XL tonometer in clinical practice. ...
The Ocular Response Analyzer (ORA) is the only instrument in the world capable of measuring Corneal Hysteresis (CH); an indication of the biomechanical properties of the cornea.
We present a multimodal imaging system which combines multiphoton microscopy and optical coherence tomography to visualize the morphological structures, and to quantify the refractive index (RI) and thickness of cornea. The morphological similarities and differences at different corneal layers across various species are identified. In the piscine and human corneas, the stromata exhibit thin fibers that indicate an overall collagen direction. Human corneas display collagen micro-folds which cause increased light attenuation. In the murine, porcine and bovine corneas, the stromata show interwoven collagen patterns. The Bowmans layer and the Descemets membrane are also distinguished in some species. The RI and thicknesses are quantified for the epithelium and the stromal layers respectively, where the epithelium is found to have slightly higher RI than the stroma. The average epithelial and stromal RI are, respectively, 1.371 ± ...
What is a corneal transplant?. A corneal transplant is where the abnormal cloudy or scarred patients cornea is removed and a donor cornea (the clear window on the front of the eye, which has been obtained from someone who has donated their cornea) replaces the abnormal patients cornea.. When is a corneal transplant needed?. A corneal transplant may be needed when the cornea is permanently scarred, or the corneal shape is very abnormal (as in keratoconus) or when the endothelial pumping cells at the back of the cornea are not functioning well (as in Fuchs dystrophy). A corneal transplant (also known as a corneal graft) is only worth doing when the inside of the eye (retina and optic nerve) is still functioning well. The camera analogy is that ...
To investigate the effect of aging on ocular parameters, including intraocular pressure (IOP), measured with different tonometry methods in healthy young (HY) and healthy elderly (HE) subjects and to study the effect of corneal parameters on tonometry methods. In this prospective, cross-sectional study, fifty eyes of 50 HY subjects (28 females, 22-31 years of age) and 43 eyes of 43 HE subjects (22 females, 64-79) were included. IOP was measured with four tonometry methods in a standardized order: ocular response analyser (ORA), dynamic contour tonometry (DCT), applanation resonance tonometry (ART) and Goldmann applanation tonometry (GAT). Other measurements included axial length (AL), central corneal thickness (CCT), corneal curvature (CC), anterior chamber volume (ACV), corneal hysteresis (CH) and corneal resistance factor (CRF). The mean IOP (HY/HE; mmHg +/- standard ...
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.. ...
https://www.millioninsights.com/industry-reports/single-vision-lenses-market. With ordinary plastic lenses, a strong prescription can result in thicker, heavier glasses. In contrast, high0-index lens material will reduce thickness for greater comfort and a better appearance. Single Vision Lenses Market is classified, by applications into Myopia, Hyperpia, Astigmatism, presbyopia and combination of these conditions.. Single Vision Lenses Market is segmented, geographically into North America, Europe (Eastern Europe, Western Europe), Asia Pacific, Latin America, Middle East and Africa. North America accounted for the largest market share of the Single Vision Lenses Market and is expected to remain dominant over the forecast period. In North America, the U.S. is leading sub-segment and it is expected to remain dominant in forecast period due to increasing prevalence of ophthalmic cases. In the U.S. ...
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steadily growing citation index and is recognized as the leading peer-reviewed journal for cornea specialists.. Cornea offers the latest clinical and basic research on the cornea and anterior segment of the eye. The journal presents the most up-to-date advances in the understanding of the structure, function, and pathology of the cornea, as well as medical and surgical approaches to managing diseases and disorders of the cornea. Corneal specialists who are members of the Cornea Society and other subscribing ophthalmologists with an interest in this subspecialty read the journal. Cornea Journal is the official peer-reviewed journal of the Cornea Society.. Circulation: ...
This prospective observational study enrolled a total of 60 eyes with corneal astigmatism greater than 1 diopter, which underwent uncomplicated phacoemulsification with Toric IOL implantation. The surgical procedures were performed by the same experienced surgeon, using an identical surgical technique. 20 eyes were implanted with an Alcon AcrySof® Toric IOL, 20 eyes with an Abbott Tecnis® Toric IOL and 20 eyes received a Bausch + Lomb enVista® Toric IOL. Rotational stability and uncorrected visual acuity (UCVA) were measured at the first postoperative day, at the end of the first month, at the third month and finally at the sixth month after surgery ...
The cornea is the primary refractive element of the eye and is also fundamental to the protection of the visual system. Collagen is the major constituent of the cornea, where it is organised in a lattice that enables corneal transparency. Proteoglycan macromolecules are thought to regulate the diameter and spatial order of collagen fibrils in the cornea, which are both pre-requisites for corneal transparency, although the mechanisms by which they organise fibrils are not fully elucidated. This investigation examined the morphology, morphometry and organisation of proteoglycans three-dimensionally, in both normal and genetically altered mouse corneas, to gain a greater understanding of proteoglycan structure-function relationships. In summary, we found that proteoglycans are primarily responsible for the remarkable collagen organisation in the mouse cornea, which allows for ...
VIRAL KERATOCONJUNCTIVITIS Description: Audio discussion (with clinical photos) of the various types of viral infections that effect the cornea with an emphasis on epidemic keratoconjunctivitis (EKC) and epithelial Herpes simplex keratitis. Course Outline: CORNEA, CORNEA, CORNEA Part 3: Viral Keratoconjunctivitis I. Adenovirus A. Aggravating factors include: 1. Sunlight (ultraviolet) 2. Trauma 3. Extreme heat or cold 4. Fever 5. Steroids 6. Systemic (or ocular) disease 7. Surgery B. Subjective presentation 1. Discomfort ranges from mild to severe symptoms 2. Mild visual fluctuations (increasing with EKC) 3. Usually mild to moderate
Refractive error, also known as refraction error, is a problem with focusing light accurately onto the retina due to the shape of the eye. The most common types of refractive error are near-sightedness, far-sightedness, astigmatism, and presbyopia. Near-sightedness results in far away objects being blurry, far-sightedness and presbyopia result in close objects being blurry, astigmatism causes objects to appear stretched out or blurry. Other symptoms may include double vision, headaches, and eye strain. Near-sightedness is due to the length of the eyeball being too long, far-sightedness the eyeball too short, astigmatism the cornea being the wrong shape, and presbyopia aging of the lens of the eye such that it cannot change shape sufficiently. Some refractive errors occur more often among those whose parents are affected. Diagnosis is by eye examination. Refractive errors are corrected with eyeglasses, contact lenses, or surgery. Eyeglasses ...
In corneal transplant, also known as keratoplasty, a patients damaged corneais replaced by the cornea from the eye of a human cadaver. This is the single most common type of human transplant surgery and has the highest success rate. Eye banks acquire and store eyes from donor individuals largely to supplythe need for transplant corneas.. Corneal transplant is used when vision is lost in an eye because the cornea has been damaged by disease or traumatic injury. Some of the disease conditions that might require corneal transplant include the bulging outward of the cornea (keratoconus), a malfunction of the inner layer of the cornea (Fuchs dystrophy), and painful swelling of the cornea (pseudophakic bullous keratopathy). Some of these conditions cause cloudiness of the cornea; others alter itsnatural curvature, which can also ...
Pre Descemets endothelial keratoplasty (PDEK) is a kind of endothelial keratoplasty, where the pre descemets layer (PDL) along with descemets membrane (DM) and endothelium is transplanted. Conventionally in a corneal transplantation, doctors use a whole cornea or parts of the five layers of the cornea to perform correction surgeries. In May 2013, Dr Harminder Dua discovered a sixth layer between the stroma and the descemet membrane which was named after him as the Duas layer. In the PDEK technique, doctors take the innermost two layers of the cornea, along with the Duas layer and graft it in the patients eye. The normal cornea (Fig 1) has from the front to the back the following layers: 1. Epithelium 2. Bowmans membrane 3. Stroma 4. Pre Descemets layer 5. Descemets membrane 6. Endothelium For the human eye to see, the cornea or the front window of the eye should be clear or transparent. For ...
Looking for online definition of anterior surface of petrous part of temporal bone in the Medical Dictionary? anterior surface of petrous part of temporal bone explanation free. What is anterior surface of petrous part of temporal bone? Meaning of anterior surface of petrous part of temporal bone medical term. What does anterior surface of petrous part of temporal bone mean?
Corneal disease is the second most common cause of blindness in the word. It is estimated that 45 million people worldwide are bilaterally blind and 10 million are affected by corneal blindness. Corneal blindness mostly affects the population in the equatorial zone, due to the high exposure to UV light. Corneal grafting presents complications such as rejections and the lack of donor material and resources. Conventional cornea grafting (keratoplasty) is not advised for patients with bilateral corneal blindness or for those who suffer from a range of clinical problems including tear deficiency, chemical burns and uncontrollable intraocular pressure. At present, an artificial cornea, i.e. a keratoprosthesis (KRPO), is the only alternative to keratoplasty (corneal donor transplantation). Cornea implants consist of a clear optic part and a surrounding ring known ...
AIM: To evaluate the clinical utility of automated refraction (AR) and keratometry (KR) compared with subjective or manifest refraction (MR) after cataract or refractive lens exchange surgery with implantation of Lentis Mplus X (Oculentis GmbH) refractive multifocal intraocular lens (IOL). METHODS: Eighty-six eyes implanted with the Lentis Mplus X multifocal IOL were included. MR was performed in all patients followed by three consecutive AR measurements using the Topcon KR-8000 autorefractor. Assessment of repeatability of consecutive AR before and after dilation with phenylephrine 10%, and comparison of the AR and KR with MR using vector analysis were performed at 3mo follow-up. RESULTS: Analysis showed excellent repeatability of the AR measurements. Linear regression of AR versus MR showed good correlation for sphere and spherical equivalent, whereas the correlation for astigmatism was low. The mean difference AR-MR was -1.28 0.29 diopters (D) for sphere. Astigmatism ...
TY - JOUR. T1 - Lysophosphatidic acid activates TGFBIp expression in human corneal fibroblasts through a TGF-β1-dependent pathway. AU - Jeon, Eun Su. AU - Kim, Jae Ho. AU - Ryu, Hyunmi. AU - Kim, Eung Kweon. PY - 2012/6/1. Y1 - 2012/6/1. N2 - Granular corneal dystrophy type 2 (GCD2) is an autosomal dominant disease caused by a R124H point mutation in the transforming growth factor-β-induced gene (TGFBI). However, the cellular role of TGFBI and the regulatory mechanisms underlying corneal dystrophy pathogenesis are still poorly understood. Lysophosphatidic acid (LPA) refers to a small bioactive phospholipid mediator produced in various cell types, and binds G protein-coupled receptors to enhance numerous biological responses, including cell growth, inflammation, and differentiation. LPA levels are elevated in injured cornea and LPA is involved in proliferation and wound healing of cornea epithelial cells. Accumulating ...
Aim: To evaluate the agreement between intra-ocular pressure (IOP) measurements with the Diaton and the Goldmann applanation tonometers (GAT). Methods: In this cross-sectional observational study, a total of 196 eyes of 196 participants (66 patients
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.. ...
PURPOSE: The present study was conducted to investigate healing of alkali-burned corneas in MRL/MpJ (MRL) mice. METHODS: Gross, clinical, and histologic criteria were used to compare healing of alkali-burned corneas in MRL and control C57BL/6J (B6) mice. Effects of neutrophil depletion of B6 mice and allogeneic reconstitution of B6 mice with MRL bone marrow on wound healing were evaluated. Gene expression patterns in normal and wounded corneas were surveyed with array-based quantitative real-time RT-PCR (AQPCR). RESULTS: MRL mice showed accelerated reepithelialization and decreased corneal opacity compared with B6 mice after alkali wounding. Marked inflammatory cell infiltration and fibrosis were evident in the corneas and anterior chambers of B6 mice. MRL mice showed less severe lesions, except for stromal edema. Rapid reepithelialization and reduced keratitis/iritis were also observed in ...
Cataracts - including surgery with premium lenses, refractive lens exchange to correct myopia, hyperopia and astigmatism, laser corrective eye surgery to correct myopia, hyperopia and astigmatism, phakic lenses to correct myopia, hyperopia and astigmatism, dry eyes, blepharitis and meibomian gland disease, keratoconus, cornea ...
1.0 Diopters of regular corneal astigmatism in both eyes. NOTE: look for consistency between manual keratometry, auto-keratometry and simulated keratometry measures to ensure regular astigmatism prior to enrollment. Subjects who wear contact lenses must discontinue its use for at least 2 weeks (soft contact lens) and at least 3 weeks (gas permeable contact lens) and until corneal topography shows stability prior to preoperative study measurements ...
Results Sphere changed from −1.77±6.57D (−11.00 to 7.00) preoperatively to 0.08±0.79D (−1.25 to 1.75) postoperatively (p=0.211), and cylinder changed from −2.95±1.71D (−7.00 to −0.75) to −1.40±1.13D (−3.25 to 0.00) (p=0.016). UDVA (logMAR) changed from 1.33±0.95 (0.40 to 2.77) to 0.32±0.38 (0.00 to 1.30) (p=0.008) and CDVA (logMAR) changed from 0.32±0.45 (0.01 to 1.77) to 0.20±0.36 (−0.03 to 1.30) (p=0.013). Efficacy and safety indexes were 1.38±0.58 and 1.17±0.66, respectively. Refraction and corneal topography were stable during the follow-up (9.10±5.54 months, 3-15). ...
Macular corneal dystrophy (MCDC; sometimes also Fehr corneal dystrophy) is a rare pathological condition affecting the stroma of cornea. The first signs are usually noticed in the first decade of life, and progress afterwards, with opacities developing in the cornea. There is also a predisposition to developing painful recurrent corneal erosions. MCDC is inherited in autosomal recessive fashion and is thought to be caused by the lack or abnormal confuguration of keratan sulfate. Most cases of MCD are caused by mutations in CHST6 gene. The condition was first described by Arthur Groenouw in 1890.. Alan N. Carlson, M.D., Professor of Ophthalmology and Chief of the Corneal and Refractive Surgery Service at the Duke Eye Center demonstrates the basic techniques behind successful corneal transplantation (penetrating keratoplasty) in a patient with visually significant ...
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 ...
Congenital stromal corneal dystrophy is caused by mutations in the DCN gene. This gene provides instructions for making a protein called decorin, which is involved in the organization of collagens. Collagens are proteins that strengthen and support connective tissues such as skin, bone, tendons, and ligaments. In the cornea, well-organized bundles of collagen make the cornea transparent. Decorin ensures that collagen fibrils in the cornea are uniformly sized and regularly spaced.. Mutations in the DCN gene lead to the production of a defective version of decorin. This abnormal protein interferes with the organization of collagen fibrils in the cornea. As poorly arranged collagen fibrils accumulate, the cornea becomes cloudy. These corneal changes lead to reduced visual acuity and related eye abnormalities. ...
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TY - JOUR. T1 - Actin filament organization during endothelial wound healing in the rabbit cornea. T2 - Comparison between transcorneal freeze and mechanical scrape injuries. AU - Ichijima, H.. AU - Petroll, Walter M. AU - Barry, P. A.. AU - Andrews, P. M.. AU - Dai, M.. AU - Cavanagh, Harrison D. AU - Jester, J. V.. PY - 1993/1/1. Y1 - 1993/1/1. N2 - Purpose. To compare and contrast the in vivo mechanism of wound healing after mechanical scrape and transcorneal freeze (TCF) injury in a rabbit eye model by examining changes in the cytoskeletal organization of contractile, filamentous actin (f-actin) microfilaments as relates to differences in cell migration or translocation during endothelial repair. Methods. Endothelial wound healing after mechanical scrape and transcorneal freeze injury was studied in rabbit eyes using laser scanning confocal microscopy (LSCM). Central corneal mechanical scrape injury was made using an ...
RESULTS: Ten years after surgery, 45.5% of eyes in the LASIK group achieved uncorrected visual acuity (UCVA) of 20/40 or better compared to 31.3% in the PRK group. Mean efficacy indices after 10 years in both groups were similar (0.87 in the LASIK group and 0.82 in the PRK group, P=.51). Twenty-one (41%) eyes in the PRK group were within +/-1.00 D whereas 60 (42.5%) eyes from the LASIK group were within +/-1.00 D 10 years after surgery. Six (14%) eyes from the PRK group lost 2 or more lines of BSCVA compared to 7 (6%) eyes from the LASIK group ...
PURPOSE To investigate whether corneal epithelial cells of individuals with lattice corneal dystrophy (LCD) possess an intrinsic defect. DESIGN Retrospective case-control study. METHODS The medical charts of nine individuals with LCD and those of 14 patients with keratoconus and 11 patients with corneal leukoma (controls), all of whom underwent penetrating keratoplasty (PKP) in one eye at Yamaguchi University Hospital between February 1998 and November 2001, were examined for the time for epithelial resurfacing after surgery. RESULTS The time required for resurfacing of the corneal epithelium after PKP was significantly greater in LCD patients (8.56 +/- 4.95 days, mean +/- SD) than in patients with either keratoconus (1.71 +/- 0.91 days, P = .006) or corneal leukoma (3.00 +/- 1.95 days, P = .03). CONCLUSIONS Corneal epithelial wound healing was delayed in LCD patients after PKP, suggesting that the ...
Purpose : To compare central corneal thickness (CCT), corneal endothelial cell density, and lens capsule thickness in normotensive patients with and without pseudoexfoliation syndrome (PXS) Methods : This was a prospective, comparative, descriptive study. Normotensive candidates for cataract surgery with (study group) and without (control group) PXS were enrolled in the study. CCT ...
Objective:To assess the efficacy of prophylactic topical antiviral therapy after penetrating keratoplasty for herpes simplex keratitis in the postoperative peri
APPROVAL FOR THE TRULIGN TORIC POSTERIOR CHAMBER INTRAOCULAR LENS (MODELS: AT50T, BL1AT AND BL1UT) AND TRULIGN TORIC CALCULATOR. THIS DEVICE IS INDICATED FOR PRIMARY IMPLANTATION IN THE CAPSULAR BAG OF THE EYE FOR THE VISUAL CORRECTION OF APHAKIA AND POSTOPERATIVE REFRACTIVE ASTIGMATISM SECONDARY TO REMOVAL OF A CATARACTOUS LENS IN ADULT PATIENTS WITH OR WITHOUT PRESBYOPIA WHO DESIRE REDUCTION OF RESIDUAL REFRACTIVE CYLINDER WITH INCREASED SPECTACLE INDEPENDENCE ANDIMPROVED UNCORRECTED NEAR, INTERMEDIATE AND DISTANCE VISION ...
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 ...
PURPOSE. To demonstrate the feasibility of indirectly measuring the precorneal tear film thickness and pre- and postlens tear film (PLTF) thickness using optical coherence tomography (OCT). METHODS. Central corneal thickness (C1) which includes the tear film (T) of both eyes of 40 non-contact lens wearers was measured using OCT after calibration. The mean age of the 40 subjects was 31.2 ± 9.3 years with a mean horizontal K-reading of 7.87 mm. Rigid contact lenses with base curves 0.3- to 0.5-mm steeper than the flattest K of the eye were fitted to measure real corneal thickness (C2), independently of the postlens tear film. T was calculated by T = C1 - C2. To measure pre- and postlens tear film thickness, Focus Night & Day and Acuvue lenses (Vistakon, Johnson & Johnson Vision Care, Jacksonville, FL) were fitted on both eyes. Central soft ...
Herpetic simplex keratitis, also known as herpetic keratoconjunctivitis and herpesviral keratitis, is a form of keratitis caused by recurrent herpes simplex virus (HSV) infection in the cornea. It begins with infection of epithelial cells on the surface of the eye and retrograde infection of nerves serving the cornea. Primary infection typically presents as swelling of the conjunctiva and eyelids (blepharoconjunctivitis), accompanied by small white itchy lesions on the corneal surface. The effect of the lesions varies, from minor damage to the epithelium (superficial punctate keratitis), to more serious consequences such as the formation of dendritic ulcers. Infection is unilateral, affecting one eye at a time. Additional symptoms include dull pain deep inside the eye, mild to acute dryness, and sinusitis. Most primary infections resolve spontaneously in a few weeks. Healing can be aided by the use of oral and topical antivirals. Subsequent recurrences may ...
Case Report DOI:10.14744/bej.2019.79553 Beyoglu Eye J 2019; 4(2): 126-129 Manual Intracorneal Silicone Oil Insertion for Symptomatic Treatment of Bullous Keratopathy in a Patient with Corneal Scarring Selim Genc, Semih Cakmak, Yusuf Yildirim Department of Ophthalmology, University of Health Sciences, Beyoglu Eye Training and Research Hospital, Istanbul, Turkey Abstract Bullous keratopathy is a result of endothelial loss and the failure of the remaining corneal epithelium to pump leaking water molecules away from the corneal tissue, causing overhydration. In eyes with good visual potential, keratoplasty is the primary treatment. There are also several other approaches to provide temporary improvement until a permanent solution with keratoplasty can be achieved. These alternatives include hypertonic topical sodium chloride (5%) drops, bandage contact lenses, anterior stromal puncture, phototherapeutic keratectomy, amniotic ...
Therapeutic contact lenses are useful in a variety of ocular surface diseases. Their main indications are: to relieve the pain; protect ocular surface; promote corneal healing and epithelial regeneration; seal a leaking corneal wound and deliver ophthalmic drugs on the ocular surface. There are several kinds of lens designs and materials, and their choice is dependent on the specific disease to be treated, the duration of treatment and the physiologic needs of the diseased cornea. Bullous keratopathy, recurrent epithelial erosion syndrome, dry eye and postoperative epithelial defects are amongst their indications. Therapeutic contact lenses should not be indicated in the presence of active infectious keratitis or when the patient is not compliant. Corneal neovascularization, giant papillary conjunctivitis and infectious keratitis are serious complications, which can be prevented by correctly ...
When your eyes are closed with contacts on, the oxygen exchange to your eye is inhibited even more than normal. This results in increased swelling of the cornea (edema) and can cause the contact lens to fit improperly, which can lead to acute red eye irritation. If the cornea is repeatedly deprived of oxygen (hypoxia), the eye may form new blood vessels (corneal neovascularization) or improperly formed cells that may rupture (corneal microcysts). Complications can change the surface and shape of the cornea, ultimately making it unsafe to wear contact lenses. To counter this, contact lens manufacturers have created extended wear contact lenses which increase the oxygen permeability of contact lenses. These contacts are approved for up to 30 days continuous wear, but these claims must be taken with caution. In the ...
15 eyes of 15 patients with permanent anterior corneal opacities where treated using OCT-guided Transepithelial Phototherapeutic Keratectomy . The etiology of the opacities was of various nature: intractable haze following surface corneal refractive surgery, ocular pemphigoid, ocular trauma, scarring of the cornea following herpetic stromal keratitis. The mean depth of the opacities was 107µm (range from 55 to 199 µm ). The depth of treatment was preoperatively calculated using OCT of the anterior segment. The transepithelial phototherapeutic keratectomies were performed using the Scwhind Amaris 500e excimer laser ...
Thicker corneas and steeper posterior corneal curvature were seen in eyes that underwent Descemets stripping automated endothelial keratoplasty compared with eyes that underwent Descemets membrane endothelial keratoplasty, according to a study. The retrospective study included 20 eyes of 10 patients with Fuchs endothelial dystrophy who underwent DSAEK in one eye and DMEK in the contralateral eye. Four DMEK eyes and three DSAEK eyes had cataracts that were removed concurrently with corneal transplantation. Four DMEK eyes and four DSAEK eyes were pseudophakic and had posterior chamber IOLs. Two DMEK eyes and (Read more...) Full Story →. ...
To present a method, alternative to penetrating keratoplasty, for the restoration of impaired corneal clarity with anterior stromal scarring following long-standing corneal graft failure. A 48-year old female who had previously underwent Descemet stripping automated endothelial keratoplasty (DSAEK) for the treatment of pseudophakic bullous keratopathy, presented with long-standing corneal oedema and anterior corneal scarring. A significant improvement in corrected distance visual acuity was demonstrated, as corneal clarity was restored following graft exchange and phototherapeutic keratectomy (PTK). The combination of corneal graft exchange and phototherapeutic keratectomy may represent an effective therapeutic option for long-standing corneal oedema with concomitant anterior corneal scarring after failure of a DSAEK graft.
Corneal confocal microscopy detects small fibre neuropathy in patients with upper gastrointestinal cancer and nerve regeneration in chemotherapy induced peripheral neuropathy Academic Article ...
Abstract Objective: A population of stem cells (SCs) is responsible for maintenance and repair of the ocular surface. These stem cells can become deficient as a result of various diseases affecting the ocular surface. Depending on the extent of damage, the clinical features can vary from mild discomfort to substantial pain and/or blindness. The growing field of tissue engineering and advances in stem cell research offer promising new alternatives for these disorders. This student thesis will provide an overview of the human ocular surface (cornea, limbus, and conjunctiva), ocular surface stem cell deficiency, and treatment possibilities. Methods: This student thesis is based on a number of review articles and original articles on PubMed using the search words limbal, limbal stem cell deficiency, conjunctival and/or ocular surface reconstruction. Only papers written in English were considered. Findings: There are different possible methods for treating ocular surface stem cell deficiency by ...
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,
Fuchs Dystrophy is a type of corneal disease that affects the inner most layer of the cornea-the endothelium. Fuchs Dystrophy is slowly progressive, is found in both eyes and is slightly more common in women than men. While we can see Fuchs Dystrophy in people in their 30s and 40s, it usually does not compromise vision until people are in their 50s or 60s.. About Fuchs Dystrophy. The endothelial cells are responsible for pumping water out of the cornea and helping to maintain the corneal transparency. While the reason is poorly understood, in Fuchs Dystrophy, the endothelial cells die, which make the endothelium less efficient in its pumping activity. This results in the cornea swelling and distorting vision. Fuchs Dystrophy Risks & Severity. Researchers reporting in the journal Investigative Ophthalmology and Visual Science studied the effects of smoking, and other risk factors, on the development of advanced Fuchs ...
For people with Keratoconus contact lenses are often the best way to achieve vision correction. There are many different types of lenses and this article looks at the limitations of Hydrogel lenses for Keratoconus.. Keratoconus is a disease of the eye. The cornea, which is the front part of the eye, thins and becomes misshapen leading to the front of the eye developing an irregular cone shape.. This bulging effect results in distortion of the light entering the eye causing blurring and ghosting of images.. While spectacles may produce some correction for early, or very mild, cases of Keratoconus, once the condition progresses beyond a certain point it becomes impossible to get reasonable correction with spectacles.. Contact lenses are often the next form of correction used, however there are many different types of contact lenses and some of them are more effective than others.. Hydrogel ...
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, ...
About the Book. This Ocular Surface Disease: Cornea, Conjunctiva and Tear Film is edited by Edward J. Holland, Mark J. Mannis and W. Barry Lee. This First Edition textbook incorporates current research and the latest management strategies as well as classification systems and treatment paradigms for all forms of ocular surface disease.. This is the first comprehensive resource that helps you to meet ocular surface disease challenges effectively using todays best medical and surgical approaches.. Features. - Get the complete, evidence-based guidance you need to provide optimal care for your patients with ocular surface disease ...
LASIK is perhaps the most common type of laser eye surgery for correcting vision-related problems. Hundreds of thousands of people in the United States have undergone this procedure mainly because of the immediate results of LASIK eye surgery.. Short for Laser in Situ Keratomileusis, LASIK involves the use of a laser to reshape the cornea from underneath a corneal flap. A specialized laser called an excimer laser is used to perform LASIK, as it is designed to address refractive errors like myopia, hyperopia, presbyopia, and astigmatism. It is utilized to improve vision and remove the need for eyeglasses and contact lenses.. How LASIK Works. The first step that an eye surgeon takes during a LASIK surgery is making a thin and very precise incision on the patients corneal flap using a tool called microkeratome. Using an excimer laser, the exposed corneal tissue is then reshaped in prescribed pattern, after ...
Faster recovery times and better visual outcomes are among the early results of a corneal transplant pilot study underway at the University of Michigan Kellogg Eye Center. The focus of this two-year pilot program - called the Femtosecond Laser Assisted Keratoplasty study, or FLAK - is the use of the ultrafast or femtosecond laser in performing full thickness corneal transplants.. Researchers at Kellogg were first to discover in the early 1990s that the femtosecond laser, then used for industrial purposes, had great potential for eye surgeries that traditionally required a surgical blade or knife. Through joint efforts of faculty from Kellogg and the U-M College of Engineering, the femtosecond laser was further developed, and is widely used for refractive surgery. Now, experts hope for the same success in applying this exceptionally fast and precise laser to cornea transplant surgery.. "We hope that with the use of the femtosecond laser, patients will have ...
The Table summarizes the patients demographics, ocular comorbidity, concomitant treatment, and clinical manifestations including symptoms and signs at the presentation. Conjunctival inflammation was graded according to the conjunctival injection as none (0), mild (1), moderate (2), and severe (3). The corneal surface integrity was scored as clear (0), scattered superficial punctuate keratitis (SPK; 1+), moderate SPK (2+), and diffuse SPK with or without corneal epithelial defects (3+). The tear function was assessed by the fluorescein clearance test as reported28 using the Schirmer paper strip following topical application of 5 μL of Fluroress (Akorn Inc., Abita Springs, LA). The diagnosis of dry eye disease (DED) was based on the wetting length of less than 3 mm at the 10th and 20th minute. For Case #2 who presented with epithelial basement membrane dystrophy (EBMD), the diagnosis was confirmed by observing corneal epithelial wrinkles or ...
A pair of multifocal contact lenses for a patient comprises a first corneal contact lens having a concave posterior surface and a convex anterior surface. The anterior surface is formed with a power curve including a circular intermediate vision correction zone and an annular distance vision correction zone contiguous with the intermediate vision correction zone. The distance vision correction zone is concentric or coaxial with the intermediate vision correction zone. A second corneal contact lens of the pair also a concave posterior surface and a convex anterior surface. The anterior surface of the second lens is formed with a power curve including a circular intermediate vision correction zone and an annular near vision correction zone contiguous with the respective intermediate vision correction zone. The near vision correction zone is concentric or ...

Laser-Assisted Subepithelial Keratectomy (LASEK): Background, History of the Procedure, ProblemLaser-Assisted Subepithelial Keratectomy (LASEK): Background, History of the Procedure, Problem

LASEK is specifically used to correct astigmatism, hyperopia (farsightedness), and myopia (nearsightedness). ... The cornea, the lens, and the axial length of the eye are the main contributors to the eyes refraction capability. The total ... or normal length) eye is approximately 58 diopters (D), of which 43 D come from the cornea and the remaining 15 D from the lens ... In hyperopia (farsightedness), the eye is too short or the refractive error is too weak because the cornea is too flat (see the ...
more infohttps://emedicine.medscape.com/article/1222702-overview

Patente US6197019 - Universal implant blank for modifying corneal curvature and methods of ... - Google PatentesPatente US6197019 - Universal implant blank for modifying corneal curvature and methods of ... - Google Patentes

A flap-like portion of the live cornea is removed to expose an inner surface of the cornea, and the blank is positioned on the ... hyperopia or astigmatism) of the eye needing correction, so that the laser beam ablates those portions and thus reshapes the ... The laser beam can also be directed onto certain portions of the laser surface of the cornea to ablate those surfaces of the ... The flap-like portion of the cornea is repositioned over the remaining portion of the blank, so that the remaining portion of ...
more infohttp://www.google.es/patents/US6197019?hl=es&dq=flatulence

US6436092B1 - Adjustable universal implant blank for modifying corneal curvature and methods of modifying corneal curvature...US6436092B1 - Adjustable universal implant blank for modifying corneal curvature and methods of modifying corneal curvature...

A flap-like portion of the live cornea is removed to expose an inner surface of the cornea, and the blank is positioned on the ... hyperopia or astigmatism) of the eye needing correction, so that the laser beam ablates those portions and thus reshapes the ... The laser beam can also be directed onto certain portions of the laser surface of the cornea to ablate those surfaces of the ... The flap-like portion of the cornea is repositioned over the remaining portion of the blank, so that the remaining portion of ...
more infohttps://patents.google.com/patent/US6436092B1/en

US5964776A - Internal keratome apparatus and method for using the same to form a pocket/flap between layers of a live cornea 
 ...US5964776A - Internal keratome apparatus and method for using the same to form a pocket/flap between layers of a live cornea ...

Suction is applied to the front surface of the cornea to stabilize the cornea during the pocket forming process. ... the pocket to form a flap-like layer at the front of the live cornea which is pivotally attached to the remainder of the cornea ... tool of the apparatus preferably has a circular or substantially circular cutting portion which is inserted into the cornea and ... An apparatus and method for forming a circularly or substantially circularly shaped pocket between layers of a live cornea, and ...
more infohttps://patents.google.com/patent/US5964776A/en

Ears, Eyes, Teeth, Throat | Health and AboveEars, Eyes, Teeth, Throat | Health and Above

If the range of axial length of the eyeball and the arching of the cornea are within normal range a normal lens will be able to ... Reduced axial length of the eyeball and reduced arching of the cornea are known to contribute to hyperopia.. 3. Astigmatism. ... The increased axial length of the eyeball, the increased arching of the cornea and the difficulty faced by the lens in normal ... The initial focusing parameters of the eye are set by the axial length of the eyeball, the arching of the cornea and the extent ...
more infohttp://www.healthandabove.com/teeth-eyes-ears-throat/

Frontiers | Bidirectional Expression of Metabolic, Structural, and Immune Pathways in Early Myopia and Hyperopia | NeuroscienceFrontiers | Bidirectional Expression of Metabolic, Structural, and Immune Pathways in Early Myopia and Hyperopia | Neuroscience

... was used to identify gene sets correlated with ocular axial length and refraction across lens groups. Like previous studies, we ... was used to identify gene sets correlated with ocular axial length and refraction across lens groups. Like previous studies, we ... and immune pathway expression are correlated with the eye size and refractive changes induced by lens defocus. Our findings ... and immune pathway expression are correlated with the eye size and refractive changes induced by lens defocus. Our findings ...
more infohttps://www.frontiersin.org/articles/10.3389/fnins.2016.00390/full

Refractive errors - The Clinical AdvisorRefractive errors - The Clinical Advisor

Hyperopia- Images focused behind the retina due to a short eye or insufficient convergence of light through the cornea or lens ... Refractive errors are commonly caused by the failure of normal emmetropization of the eye. Subsequently, the axial length of ... Myopia- Images focused in front of the retina due to a longer eye or excessive convergence of light through the cornea or lens ... The prevalence of myopia is 9%, hyperopia 13%, and astigmatism 28% in children between the ages of 5 to 17. ...
more infohttp://www.clinicaladvisor.com/pediatrics/refractive-errors/article/622320/

The Science Behind Myopia by Brittany J. Carr and William K. StellThe Science Behind Myopia by Brittany J. Carr and William K. Stell

... occurs when the axial length of the eye is too long, and light is focussed in front of the photoreceptors (b). Hyperopia (far- ... The lenses reshape the cornea while the user is sleeping, are removed in the morning, and refractive correction is maintained ... The retina looks normal. Recently, is has been projected that 2.5 billion people (1/3 of the worlds population) will have some ... Progressive addition lenses (b) have multiple lens powers distributed across specific areas of the lens. This allows the wearer ...
more infohttp://webvision.med.utah.edu/book/part-xvii-refractive-errors/the-science-behind-myopia-by-brittany-j-carr-and-william-k-stell/

Molecular Vision: Mutations in a novel serine protease PRSS56
in families with nanophthalmosMolecular Vision: Mutations in a novel serine protease PRSS56 in families with nanophthalmos

... and correspondingly severe hyperopia. Axial lengths ranged from 15.32 to 16.12 mm with a mean of 15.71 mm. (adult normal mean ... The crystalline lenses were large, displacing the iris anteriorly. Thus far there have been no instances of angle-closure ... Like subject 172 from the first family, his central corneas were rather thin (measuring 457 and 459 microns, respectively) His ... Patients suffer from severe hyperopia as a result of their markedly reduced axial lengths, but otherwise are capable of seeing ...
more infohttp://www.molvis.org/molvis/v17/a202/

A-scan Biometry | East Valley OphthalmologyA-scan Biometry | East Valley Ophthalmology

... the lens and cornea. Measuring the axial length in this way avoids a number of common problems and has become our preferred ... of myopia in the beginning may result in unexpected post-operative hyperopia of approximately +0.50 diopters in eyes of normal ... is no corneal compression and the displayed axial length is closer to the true axial length. The difference between applanation ... Using this Advanced A-scan Biometry technique, an extra +0.32 mm is added to the displayed axial length to correct for the ...
more infohttp://doctor-hill.com/iol-main/a-scan.html

Emmetropisation after Molteno implant insertion for buphthalmos | British Journal of OphthalmologyEmmetropisation after Molteno implant insertion for buphthalmos | British Journal of Ophthalmology

The myopia due to increased axial length is only partially compensated by flattening of the cornea and lens and posterior lens ... Other ocular parameters such as corneal power, lens power, and axial length show a Gaussian distribution.1-3 Normal ocular ... While nanophthalmos with a steep cornea and small eye results in high hyperopia. ... flattening and posterior displacement of the lens, and an increase in axial length (especially vitreous length), often ...
more infohttp://bjo.bmj.com/content/85/9/1139.2

Molecular Vision: Patterns of mRNA and protein expression during minus-lens compensation and recovery in tree shrew scleraMolecular Vision: Patterns of mRNA and protein expression during minus-lens compensation and recovery in tree shrew sclera

... by the cornea, lens and anterior chamber depth. When the axial length matches the optical power, without accommodation, the ... the bottom panel shows the control eye versus normal eye difference. The dominant early response to hyperopia (-5D lens) was ... 5D lens (PMMA contact lens, 12 mm diameter; Conforma Contact Lens, Norfolk, VA) was clipped to the pedestal, holding the lens ... After 11 days of lens treatment, when most eyes had fully compensated for the lens and (as shown in prior studies [11]) axial ...
more infohttp://www.molvis.org/molvis/v17/a101/

Refractive errorsRefractive errors

Hyperopia- Images focused behind the retina due to a short eye or insufficient convergence of light through the cornea or lens ... Refractive errors are commonly caused by the failure of normal emmetropization of the eye. Subsequently, the axial length of ... Myopia- Images focused in front of the retina due to a longer eye or excessive convergence of light through the cornea or lens ... The prevalence of myopia is 9%, hyperopia 13%, and astigmatism 28% in children between the ages of 5 to 17. ...
more infohttps://www.clinicalpainadvisor.com/pediatrics/refractive-errors/article/622327/

Near-sightedness - WikipediaNear-sightedness - Wikipedia

... whereby the eye alters its growth to effectively eliminate the lens induced blur. Anatomically, the changes in axial length of ... Strongly near-sighted wearers of contact lenses do not experience these distortions because the lens moves with the cornea, ... There is evidence that lack of normal visual stimuli causes improper development of the eyeball. In this case, "normal" refers ... Hyperopia, the biological opposite of myopia, may also be used metaphorically for a value system or motivation that exhibits " ...
more infohttps://en.wikipedia.org/wiki/Near-sightedness

Bidirectional, Optical Sign-Dependent Regulation of BMP2 Gene Expression in Chick Retinal Pigment Epithelium | IOVS | ARVO...Bidirectional, Optical Sign-Dependent Regulation of BMP2 Gene Expression in Chick Retinal Pigment Epithelium | IOVS | ARVO...

... to which the cornea and crystalline lens contribute, and its axial length, which defines the position of the retina relative to ... BMP2 was up-regulated in the RPE from eyes wearing +10 D lenses, which exhibited shorter than normal vitreous chambers (VCDs) ... while positive defocusing lenses slow eye elongation. The net results in refractive terms are induced myopia and hyperopia, ... Effects of +10 D (A) and −10 D (B) lens treatments on axial length (AL), vitreous chamber depth (VCD), and choroidal thickness ...
more infohttps://iovs.arvojournals.org/article.aspx?articleid=2127137

Lasik Eye Surgery • View topic - Hyperopic wavefront correction was overcorrectedLasik Eye Surgery • View topic - Hyperopic wavefront correction was overcorrected

The most common cause of myopia and hyperopia is that the length of the eye is too long or too short. The eye focuses around ... then there is no reason for the eye to focus around an axial length refractive error. It may take a little while for your eyes ... I would love to be able to see that way I could with that lens. Have to find out what the full script actually is for my own ... If it interferes with normal vision, an application of Mitomycin C may be suggested.. croanster wrote:. Overall I think my ...
more infohttp://www.usaeyes.org/ask-lasik-expert/viewtopic.php?p=5757

Lasik Eye Surgery • View topic - Hyperopic wavefront correction was overcorrectedLasik Eye Surgery • View topic - Hyperopic wavefront correction was overcorrected

The most common cause of myopia and hyperopia is that the length of the eye is too long or too short. The eye focuses around ... then there is no reason for the eye to focus around an axial length refractive error. It may take a little while for your eyes ... I would love to be able to see that way I could with that lens. Have to find out what the full script actually is for my own ... If it interferes with normal vision, an application of Mitomycin C may be suggested.. croanster wrote:. Overall I think my ...
more infohttp://www.usaeyes.org/ask-lasik-expert/viewtopic.php?p=6260

Spotlight Cases - The American Society of Retina Specialists
 - The American Society of Retina SpecialistsSpotlight Cases - The American Society of Retina Specialists - The American Society of Retina Specialists

His axial lengths measured 18.14mm OD and 17.83mm OS on A scan. ... examination was unremarkable with clear cornea and clear lens ... Auto-refractor testing revealed only minimal hyperopia. Intraocular pressures (IOP) were within normal limits, but asymmetric ... An Amsler grid test was normal. Pupillary response and extraocular motility were normal, and color vision testing with Hardy- ... are within normal limits. Examination of external exam, lids, lashes, conjunctiva, and sclera are unremarkable. Corneas are ...
more infohttps://www.asrs.org/clinical/spotlight-case

Near-sightedness - WikipediaNear-sightedness - Wikipedia

The power of any lens system can be expressed in diopters, the reciprocal of its focal length in meters. Corrective lenses for ... Axial myopia is attributed to an increase in the eyes axial length.[50] ... Strongly near-sighted wearers of contact lenses do not experience these distortions because the lens moves with the cornea, ... There is evidence that lack of normal visual stimuli causes improper development of the eyeball. In this case, "normal" refers ...
more infohttps://en.wikipedia.org/wiki/Myopia

Emmetropia - WikipediaEmmetropia - Wikipedia

This condition of the normal eye is achieved when the refractive power of the cornea and the axial length of the eye balance ... visual acuity roughly half normal). A person with exceptionally acute vision (excellent cornea and lens and better than ... 2000). "Normal emmetropization in infants with spectacle correction for hyperopia". Invest Ophthalmol Vis Sci. 41 (12): 3726- ... By shaping the cornea, emmetropic vision can be achieved without corrective lenses. The correction for only emmetropic vision ...
more infohttps://en.wikipedia.org/wiki/Emmetropia

Ophthalmology Clinical Pearls - Nadas Notes & SummariesOphthalmology Clinical Pearls - Nada's Notes & Summaries

Myopia -, long axial length -, deep AC. *Hyperopia -, short axial length -, shallow AC (high risk of AACG) ... Dislocation of the lens -, deep AC. *Subluxation of the lens (trauma, Marfan, homocystinuria, Weill-Marchesani syndrome) -, ... Normal IOP? 10-21 mmHg. *How to measure intraocular pressure? Via two principles: *Indentation: "a force or a weight will ... Microbial: severe pain, decreased vision, edema and congestion, colored mucopurulent discharge, hazy cornea w\ infiltrates * ...
more infohttps://nadanotes.com/2018/08/18/ophthalmology-clinical-pearls/

Lisa Jordan | OSU College of OptometryLisa Jordan | OSU College of Optometry

Fink, B. A., Hill, R. M., & Jones, L. A. (1998). Effects of rigid contact lens prism ballasting on oxygen access to the cornea ... Title of Publication: Optom Vis SciTitle of Entry: Axial length and ocular shape before and after the onset of myopia. Paper ... Zadnik, K., Mutti, D. O., Mitchell, G. L., Jones, L. A., Burr, D., & Moeschberger, M. L. (2004). Normal eye growth in ... Jordan, L. A., Kleinstein, R. N., Mutti, D. O., & Zadnik, K. (2005). Hyperopia: How Do We Define Abnormal?. Archives of ...
more infohttps://optometry.osu.edu/directory/faculty/lisa-jordan

Patent US6488708 - Open chamber, elliptical, accommodative intraocular lens system - Google PatentsPatent US6488708 - Open chamber, elliptical, accommodative intraocular lens system - Google Patents

... of a human eye following extracapsular extraction of a natural crystalline lens is provided having an anterior refractive lens ... along the the line of sight of the lens and at least a second haptic segment having a first end and being connected at said ... a first haptic segment having a first end and being connected at said first end to a peripheral portion of said anterior lens ... elliptical shaped haptic accommodating support for the anterior lens within an evacuated capsular bag of a human eye. ...
more infohttp://www.google.com/patents/US6488708?dq=5787449

بیمارستان و مراکز فوق تخصصی چشم پزشکی نور-دکتر سید حسن هاشمیبیمارستان و مراکز فوق تخصصی چشم پزشکی نور-دکتر سید حسن هاشمی

Effect of anterior chamber depth on the choice of intraocular lens calculation formula in patients with normal axial length. ... Hashemi, H., et al., Descemet stripping automated endothelial keratoplasty performed by cornea fellows. Cornea, 2012. 31(9): p ... year outcomes of photorefractive keratectomy with the application of mitomycin-C in the treatment of mild to moderate hyperopia ... Hashemi, H., et al., The distribution of axial length, anterior chamber depth, lens thickness, and vitreous chamber depth in an ...
more infohttps://www.noorvision.com/fa/doctors/30/%D8%AF%DA%A9%D8%AA%D8%B1-%D8%B3%DB%8C%D8%AF-%D8%AD%D8%B3%D9%86-%D9%87%D8%A7%D8%B4%D9%85%DB%8C

The effect of positive lens defocus on ocular growth and emmetropization in the tree shrew | JOV | ARVO JournalsThe effect of positive lens defocus on ocular growth and emmetropization in the tree shrew | JOV | ARVO Journals

... normal developmental increases occurred in lens thickness and, to a lesser degree, the ocular axial length as occurs in normal ... 4 D lenses prevents the normal reduction of hyperopia seen in normal animals or animals wearing plano lenses. (B) The ... Axial length (anterior cornea to front of retina) is significantly shorter in the animals wearing positive lenses compared to ... 4 D lenses prevents the normal reduction of hyperopia seen in normal animals or animals wearing plano lenses. (B) The ...
more infohttps://jov.arvojournals.org/article.aspx?articleid=2121999
  • The LASEK technique attempts to decrease the occurrence of flap-related complications associated with LASIK and, as in PRK, is specifically helpful in patients with corneas that are otherwise too thin for LASIK. (medscape.com)
  • They followed principles formulated by Krumeich using a microkeratome to remove a portion of the cornea followed by a second plano cut, the thickness and diameter of which established refractive change. (medscape.com)
  • Failure to target a higher degree of myopia in the beginning may result in unexpected post-operative hyperopia of approximately +0.50 diopters in eyes of normal axial length. (doctor-hill.com)
  • Summit Laser then introduced its holmium:YAG laser, first successfully used by Theo Seiler, MD, in 1990 for contact laser thermal keratoplasty (LTK) for the correction of hyperopia of up to 5 diopters (D), which also eventually failed. (medscape.com)
  • The underlying mechanism involves the length of the eyeball growing too long or less commonly the lens being too strong. (wikipedia.org)
  • If OK can, in fact, control and decrease the progression of axial length growth and stop the eyes from becoming more nearsighted, then children fitted in early childhood will have their eyes return to the way they were before treatment - when their myopia levels were low - not to where their eyeball lengths would otherwise have been years later when they stop lens wear. (envisionmagazine.ca)
  • A relatively thin lens and relatively dilated pupil are also associated. (wikipedia.org)
  • To increase our understanding of the mechanisms that remodel the sclera during the development of lens-induced myopia, when the sclera responds to putative "go" signals of retinal origin, and during recovery from lens-induced myopia, when the sclera responds to retinally-derived "stop" signals. (molvis.org)
  • In contrast to the cornea, the sclera, the white part of the eye, appears white because light is scattered from its unorganized cross-linked collagen fibers. (pointsdevue.com)
  • Quantitative PCR (qPCR) was used to assess the effects of short-term exposure (2 or 48 hours) to monocular +10 and −10 diopter (D) lenses, on RPE gene expression of BMP2 and its receptors. (arvojournals.org)
  • Seven groups of tree shrews were used to examine mRNA levels during minus lens compensation and recovery. (molvis.org)
  • Starting 24 days after eye opening (days of visual experience [VE]) lens compensation animals wore a monocular -5D lens for 1, 4, or 11 days. (molvis.org)
  • The different patterns of differential mRNA expression during minus lens compensation (hyperopia) and recovery (myopia) show that scleral fibroblasts distinguish between "go" and "stop" conditions. (molvis.org)
  • Less complete compensation was observed for lens powers beyond this range, indicating that the limits of compensation had been reached (Irving et al. (arvojournals.org)
  • There was also a considerable increase in the variability of responses for lens powers outside this range of compensation (Irving et al. (arvojournals.org)
  • Associations with Meibomian Gland Atrophy in Daily Contact Lens Wearers. (osu.edu)
  • A comparison of spectacle and contact lens wearing times in the ACHIEVE study. (osu.edu)
  • Randomized Trial of the Effect of Contact Lens Wear on Self-Perception in Children. (osu.edu)
  • Patients suffer from severe hyperopia as a result of their markedly reduced axial lengths, but otherwise are capable of seeing well unlike other more general forms of microphthalmia. (molvis.org)
  • This experimental design makes it challenging to separate the genes involved in growth processes from those responding to the secondary effects of lens-wear (i.e., blur and physiological stress). (frontiersin.org)
  • Identification of additional genes for nanophthalmos will improve our understanding of normal developmental regulation of eye growth. (molvis.org)
  • There is evidence of binocular global downregulation of genes at the start of both lens wear and recovery. (molvis.org)
  • One treatment group wore positive lenses binocularly, which were increased in power sequentially from +2 to +4, +6, +8, and +9.5 D over 8 weeks. (arvojournals.org)
  • [ 10 ] CK uses high radiofrequency energy that is delivered with a thin metal tip in concentric rings of multiple spots around the corneal periphery, shrinking collagen and steepening the central cornea. (medscape.com)
  • The middle layer consists of collagen fibers that are uniformly arranged making the cornea transparent. (pointsdevue.com)
  • These customized reverse-geometry rigid gas permeable (RGP) contact lenses, also known as non-surgical corneal reshaping (CR), are worn during sleep and removed on wakening and can provide patients with clear vision and all-day freedom from glasses and contact lenses, usually within one to two weeks. (envisionmagazine.ca)
  • The aim of this study is to determine and compare biometric and refractive characteristics of thalassemia major patients and normal individuals. (nih.gov)
  • Mean spherical equivalent was -0.0093 ± 0.86 D in thalassemia patients and -0.22 ± 1.33 D in the normal group. (nih.gov)
  • Mean axial length in thalassemia patients was 22.89 ± 0.70 which was significantly lower than that in normal group (23.37 ± 0.91, p = 0.000). (nih.gov)
  • The flattest meridian of the cornea (R1) was significantly steeper in thalassemia patients (7.77 ± 0.24) in comparison to normal individuals (7.85 ± 0.28). (nih.gov)
  • EUA at 11 months of age (2 months postoperatively) revealed −6.5D (myopia) in both eyes and normal IOP. (bmj.com)
  • Subsequent EUA at 13 months (8 months postoperatively) revealed normal IOP (14 mm Hg in both eyes) with horizontal corneal diameters of 13 mm Hg right and 13.5 mm Hg left and normal discs. (bmj.com)
  • Optic nerves appeared pink and sharp, and the vessels appeared normal. (asrs.org)
  • said first, second and third, longitudinally arcuate, haptics when viewed in a direction normal to an anterior face of said first lens optic, extend outwardly from a periphery of the first lens optic at an angle of approximately 30 to 40 degrees and said haptics are equally spaced about the periphery of the optic. (google.com)
  • After 11 days of lens wear, there was no differential expression. (molvis.org)