Corneal Opacity: Disorder occurring in the central or peripheral area of the cornea. The usual degree of transparency becomes relatively opaque.Eyelashes: The hairs which project from the edges of the EYELIDS.Trichiasis: A disease of the eye in which the eyelashes abnormally turn inwards toward the eyeball producing constant irritation caused by motion of the lids.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)Hair Removal: Methods used to remove unwanted facial and body hair.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)Lecithin Acyltransferase Deficiency: An autosomal recessively inherited disorder caused by mutation of LECITHIN CHOLESTEROL ACYLTRANSFERASE that facilitates the esterification of lipoprotein cholesterol and subsequent removal from peripheral tissues to the liver. This defect results in low HDL-cholesterol level in blood and accumulation of free cholesterol in tissue leading to a triad of CORNEAL OPACITY, hemolytic anemia (ANEMIA, HEMOLYTIC), and PROTEINURIA.Corneal Diseases: Diseases of the cornea.Entropion: The turning inward (inversion) of the edge of the eyelid, with the tarsal cartilage turned inward toward the eyeball. (Dorland, 27th ed)Corneal Dystrophies, Hereditary: Bilateral hereditary disorders of the cornea, usually autosomal dominant, which may be present at birth but more frequently develop during adolescence and progress slowly throughout life. Central macular dystrophy is transmitted as an autosomal recessive defect.Blindness: The inability to see or the loss or absence of perception of visual stimuli. This condition may be the result of EYE DISEASES; OPTIC NERVE DISEASES; OPTIC CHIASM diseases; or BRAIN DISEASES affecting the VISUAL PATHWAYS or OCCIPITAL LOBE.Surgery, Plastic: The branch of surgery concerned with restoration, reconstruction, or improvement of defective, damaged, or missing structures.Trachoma: A chronic infection of the CONJUNCTIVA and CORNEA caused by CHLAMYDIA TRACHOMATIS.Eyelid DiseasesTattooing: The indelible marking of TISSUES, primarily SKIN, by pricking it with NEEDLES to imbed various COLORING AGENTS. Tattooing of the CORNEA is done to colorize LEUKOMA spots.Eye Diseases: Diseases affecting the eye.Corneal Stroma: The lamellated connective tissue constituting the thickest layer of the cornea between the Bowman and Descemet membranes.Keratoplasty, Penetrating: Partial or total replacement of all layers of a central portion of the cornea.Keratoconjunctivitis: Simultaneous inflammation of the cornea and conjunctiva.Visual Acuity: Clarity or sharpness of OCULAR VISION or the ability of the eye to see fine details. Visual acuity depends on the functions of RETINA, neuronal transmission, and the interpretative ability of the brain. Normal visual acuity is expressed as 20/20 indicating that one can see at 20 feet what should normally be seen at that distance. Visual acuity can also be influenced by brightness, color, and contrast.Corneal Keratocytes: Fibroblasts which occur in the CORNEAL STROMA.Pupil Disorders: Conditions which affect the structure or function of the pupil of the eye, including disorders of innervation to the pupillary constrictor or dilator muscles, and disorders of pupillary reflexes.Eye Burns: Injury to any part of the eye by extreme heat, chemical agents, or ultraviolet radiation.Burns, ChemicalPhotorefractive 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.Esthetics: The branch of philosophy dealing with the nature of the beautiful. It includes beauty, esthetic experience, esthetic judgment, esthetic aspects of medicine, etc.Microscopy, Acoustic: A scientific tool based on ULTRASONOGRAPHY and used not only for the observation of microstructure in metalwork but also in living tissue. In biomedical application, the acoustic propagation speed in normal and abnormal tissues can be quantified to distinguish their tissue elasticity and other properties.Corneal Neovascularization: New blood vessels originating from the corneal veins and extending from the limbus into the adjacent CORNEAL STROMA. Neovascularization in the superficial and/or deep corneal stroma is a sequel to numerous inflammatory diseases of the ocular anterior segment, such as TRACHOMA, viral interstitial KERATITIS, microbial KERATOCONJUNCTIVITIS, and the immune response elicited by CORNEAL TRANSPLANTATION.Keratitis: Inflammation of the cornea.Eye Abnormalities: Congenital absence of or defects in structures of the eye; may also be hereditary.Vision, Low: Vision considered to be inferior to normal vision as represented by accepted standards of acuity, field of vision, or motility. Low vision generally refers to visual disorders that are caused by diseases that cannot be corrected by refraction (e.g., MACULAR DEGENERATION; RETINITIS PIGMENTOSA; DIABETIC RETINOPATHY, etc.).Keratan Sulfate: A sulfated mucopolysaccharide initially isolated from bovine cornea. At least two types are known. Type I, found mostly in the cornea, contains D-galactose and D-glucosamine-6-O-sulfate as the repeating unit; type II, found in skeletal tissues, contains D-galactose and D-galactosamine-6-O-sulfate as the repeating unit.Anterior Eye Segment: The front third of the eyeball that includes the structures between the front surface of the cornea and the front of the VITREOUS BODY.Lens Nucleus, Crystalline: The core of the crystalline lens, surrounded by the cortex.Keratitis, Herpetic: A superficial, epithelial Herpesvirus hominis infection of the cornea, characterized by the presence of small vesicles which may break down and coalesce to form dendritic ulcers (KERATITIS, DENDRITIC). (Dictionary of Visual Science, 3d ed)Lasers, Excimer: Gas lasers with excited dimers (i.e., excimers) as the active medium. The most commonly used are rare gas monohalides (e.g., argon fluoride, xenon chloride). Their principal emission wavelengths are in the ultraviolet range and depend on the monohalide used (e.g., 193 nm for ArF, 308 nm for Xe Cl). These lasers are operated in pulsed and Q-switched modes and used in photoablative decomposition involving actual removal of tissue. (UMDNS, 2005)Lens Cortex, Crystalline: The portion of the crystalline lens surrounding the nucleus and bound anteriorly by the epithelium and posteriorly by the capsule. It contains lens fibers and amorphous, intercellular substance.Corneal Transplantation: Partial or total replacement of the CORNEA from one human or animal to another.Vision Disorders: Visual impairments limiting one or more of the basic functions of the eye: visual acuity, dark adaptation, color vision, or peripheral vision. These may result from EYE DISEASES; OPTIC NERVE DISEASES; VISUAL PATHWAY diseases; OCCIPITAL LOBE diseases; OCULAR MOTILITY DISORDERS; and other conditions (From Newell, Ophthalmology: Principles and Concepts, 7th ed, p132).Contact Lenses: Lenses designed to be worn on the front surface of the eyeball. (UMDNS, 1999)Epithelium, Corneal: Stratified squamous epithelium that covers the outer surface of the CORNEA. It is smooth and contains many free nerve endings.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.Phosphatidylcholine-Sterol O-Acyltransferase: An enzyme secreted from the liver into the plasma of many mammalian species. It catalyzes the esterification of the hydroxyl group of lipoprotein cholesterol by the transfer of a fatty acid from the C-2 position of lecithin. In familial lecithin:cholesterol acyltransferase deficiency disease, the absence of the enzyme results in an excess of unesterified cholesterol in plasma. EC 18.104.22.168.
Kramers' opacity law: Kramers' opacity law describes the opacity of a medium in terms of the ambient density and temperature, assuming that the opacity is dominated by bound-free absorption (the absorption of light during ionization of a bound electron) or free-free absorption (the absorption of light when scattering a free ion, also called bremsstrahlung).Phillips (1999), p.Eyelash: An eyelash or simply lash is one of the hairs that grows at the edge of the eyelid. Eyelashes protect the eye from debris and perform some of the same function as whiskers do on a cat or a mouse in the sense that they are sensitive to being touched, thus providing a warning that an object (such as an insect or dust mite) is near the eye (which then closes reflexively).Trichiasis: (ILDS H02.010) |Congenital cataractHair removal: Hair removal, also known as epilation or depilation, is the deliberate removal of body hair.Lecithin cholesterol acyltransferase deficiencyBullous keratopathyEntropionLattice corneal dystrophyBlind People's Association: The Blind People’s Association (BPA) is an organisation in India which promotes comprehensive rehabilitation of persons with all categories of disabilities through education, training, employment, community based rehabilitation, integrated education, research, publications, human resource development and other innovative means.Aesthetic Surgery Journal: Aesthetic Surgery Journal is a peer-reviewed medical journal that covers the field of plastic surgery. The journal's editor-in-chief is Foad Nahai (Emory University School of Medicine).International Coalition for Trachoma ControlBlepharochalasisList of tattoo artists: This is a list of notable tattoo artists.Neuro-ophthalmology: Neuro-ophthalmology is an academically-oriented subspecialty that merges the fields of neurology and ophthalmology, often dealing with complex systemic diseases that have manifestations in the visual system. Neuro-ophthalmologists initially complete a residency in either neurology or ophthalmology, then do a fellowship in the complementary field.Automated lamellar keratoplasty: Automated Lamellar Keratoplasty, commonly abbreviated to ALK uses a device called a microkeratome to separate a thin layer of the cornea and create a flap. The flap is then folded back, and the microkeratome removes a thin disc of corneal stroma below.KeratoconjunctivitisLogMAR chart: A LogMAR chart comprises rows of letters and is used by ophthalmologists and vision scientists to estimate visual acuity. This chart was developed at the National Vision Research Institute of Australia in 1976, and is designed to enable a more accurate estimate of acuity as compared to other charts (e.Corneal keratocyte: Corneal keratocytes (corneal fibroblasts) are specialized fibroblasts residing in the stroma. This corneal layer, representing about 85-90% of corneal thickness, is built up from highly regular collagenous lamellae and extracellular matrix components.Flashlight: A flashlight or torch in British English, is a portable hand-held electric light. Usually, the source of the light is a small incandescent light bulb or light-emitting diode (LED).Chemical eye injury: Chemical eye injury or chemical burns to the eye are due to either an acidic or alkali substance getting in the eye. Alkalis are typically worse than acidic burns.Corrosive substancePhotorefractive keratectomyAtomic force acoustic microscopy: Atomic Force Acoustic Microscopy (AFAM) is a type of scanning probe microscopy (SPM). It is a combination of acoustics and atomic force microscopy.Corneal neovascularizationChronic superficial keratitisLow vision assessment: Low vision is both a subspeciality and a condition. Optometrists and Ophthalmologists after their training may undergo further training in Low vision assessment and management.Anterior segment mesenchymal dysgenesis: Anterior segment dysgenesis (ASD) is a failure of the normal development of the tissues of the anterior segment of the eye. It leads to anomalies in the structure of the mature anterior segment, associated with an increased risk of glaucoma and corneal opacity.Photoablation: Photoablation is the use of light or lasers to destroy tissues. The excimer laser of deep ultra-violet light is mainly used in Photoablation.Corneal transplantationOperation Eyesight Universal: Operation Eyesight Universal is a Canada-based international development organisation, founded in 1963. It works to prevent avoidable blindness and to cure blindness that is treatable.Fairness to Contact Lens Consumers Act: The Fairness to Contact Lens Consumers Act (, 117 Stat. 2025, 2026, 2027, 2028 and 2029, codified at et seq.Guiding Eyes for the Blind: Yorktown Heights, New YorkAcyltransferase
(1/277) Phenotype of autosomal recessive congenital microphthalmia mapping to chromosome 14q32.
BACKGROUND: Congenital microphthalmia (OMIM: 309700) may occur in isolation or in association with a variety of systemic malformations. Isolated microphthalmia may be inherited as an autosomal dominant, an autosomal recessive, or an X linked trait. METHODS: Based on a whole genome linkage analysis, in a six generation consanguineous family with autosomal recessive inheritance, the first locus for isolated microphthalmia was mapped to chromosome 14q32. Eight members of this family underwent clinical examination to determine the nature of the microphthalmia phenotype associated with this locus. RESULTS: All affected individuals in this family suffered from bilateral microphthalmia in association with anterior segment abnormalities, and the best visual acuity achieved was "perception of light". Corneal changes included partial or complete congenital sclerocornea, and the later development of corneal vascularisation and anterior staphyloma. Intraocular pressure, as measured by Schiotz tonometry, was greatly elevated in many cases. CONCLUSIONS: This combination of ocular defects suggests an embryological disorder involving tissues derived from both the neuroectoderm and neural crest. Other families with defects in the microphthalmia gene located on 14q32 may have a similar ocular phenotype aiding their identification. (+info)
(2/277) A first British case of fish-eye disease presenting at age 75 years: a double heterozygote for defined and new mutations affecting LCAT structure and expression.
Fish-eye disease is a familial syndrome with corneal opacification, major high density lipoprotein (HDL) deficiency in plasma, significant cholesterol esterification in plasma on non-HDL lipoproteins, generally without premature coronary disease. This first British male case from unrelated British parents had infarcts when aged 49 and 73 years but was asymptomatic at age 81 years, with plasma cholesterol 4.3-7.1 mmol/litre, triglycerides 1.8-2.2 mmol/litre, HDL cholesterol < 0.1 mmol/litre, apolipoprotein A-I < 0.16 g/litre, lipoprotein(a) 0.61 g/litre. Cholesterol esterification was impaired using HDL-3 and A-I proteoliposomes but not using VLDL/IDL/LDL. The findings are those of LCAT deficiency with the classic fish-eye disease defect. Most of the 22 reported cases were homozygous or heterozygous for a Thr-Ile mutation at codon 123 of the lecithin:cholesterol acyltransferase (LCAT) gene. This patient was a double heterozygote for this mutation and a second new incompletely defined mutation affecting LCAT expression as defined by reduced mass and activity in plasma. (+info)
(3/277) Functional human corneal equivalents constructed from cell lines.
Human corneal equivalents comprising the three main layers of the cornea (epithelium, stroma, and endothelium) were constructed. Each cellular layer was fabricated from immortalized human corneal cells that were screened for use on the basis of morphological, biochemical, and electrophysiological similarity to their natural counterparts. The resulting corneal equivalents mimicked human corneas in key physical and physiological functions, including morphology, biochemical marker expression, transparency, ion and fluid transport, and gene expression. Morphological and functional equivalents to human corneas that can be produced in vitro have immediate applications in toxicity and drug efficacy testing, and form the basis for future development of implantable tissues. (+info)
(4/277) Persistent corneal haze after excimer laser photokeratectomy in plasminogen-deficient mice.
PURPOSE: Excimer laser photorefractive keratectomy creates a nonvascular wound of the cornea. Fibrin deposition and resolution after excimer laser photokeratectomy were investigated in relation to corneal repair and restoration of clarity in mice with a genetic deficiency of plasminogen. METHODS: A Summit Apex Laser (Summit, Waltham, MA) was used to perform 2-mm, 175-pulse, transepithelial photoablations that resulted in deep stromal keratectomies. Photokeratectomy was performed on the corneas of plasminogen-deficient (Plg-/-) mice and littermate control animals. Eyes were examined for re-epithelialization and clarity throughout the 21-day observational period. Histologic sections were taken during the observational period and fibrin(ogen) was detected immunohistochemically. RESULTS: Re-epithelialization was rapid and complete within 3 days in both control and Plg-/- animals. Exuberant corneal fibrin(ogen) deposition was noted in Plg-/- mice and sparse fibrin(ogen) deposition in control mice on days 1 and 3 after injury. Fibrin(ogen) deposits resolved in control mice but persisted in Plg-/- mice (74% of eyes at 21 days; P < 0.004). Corneal opacification, scarring, and the presence of anterior chamber fibrin(ogen) occurred in plasminogen-deficient mice but not in control mice. CONCLUSIONS: Fibrin(ogen) deposition occurs during corneal wound repair after photokeratectomy. Impaired fibrinolysis in Plg-/- mice caused persistent stromal fibrin deposits that correlated with the development of corneal opacity. (+info)
(5/277) Relationship between structure and biochemical phenotype of lecithin:cholesterol acyltransferase (LCAT) mutants causing fish-eye disease.
In order to test the hypothesis that fish-eye disease (FED) is due to a deficient activation of lecithin:cholesterol acyltransferase (LCAT) by its co-factor apolipoprotein (apo) A-I, we overexpressed the natural mutants T123I, N131D, N391S, and other engineered mutants in Cos-1 cells. Esterase activity was measured on a monomeric phospholipid enelogue, phospholipase A(2) activity was measured on reconstituted high density lipoprotein (HDL), and acyltransferase activity was measured both on rHDL and on low density lipoprotein (LDL). The natural FED mutants have decreased phospholipase A(2) activity on rHDL, which accounts for the decreased acyltransferase activity previously reported. All mutants engineered at positions 131 and 391 had decreased esterase activity on a monomeric substrate and decreased acyltransferase activity on LDL. In contrast, mutations at position 123 preserved these activities and specifically decreased phospholipase A(2) and acyltransferase activites on rHDL. Mutations of hydrophilic residues in amphipathic helices alpha 3;-4 and alpha His to an alanine did not affect the mutants' activity on rHDL. Based upon the 3D model built for human LCAT, we designed a new mutant F382A, which had a biochemical phenotype similar to the natural T123I FED mutant. These data suggest that residues T123 and F382, located N-terminal of helices alpha 3-4 and alpha His, contribute specifically to the interaction of LCAT with HDL and possibly with its co-factor apoA-I. Residues N131 and N391 seem critical for the optimal orientation of the two amphipathic helices necessary for the recognition of a lipoprotein substrate by the enzyme. (+info)
(6/277) Ocular changes in beagle dogs following oral administration of CGS 24565, a potential hypolipidemic agent.
(11R)-N,15-dideoxo-1-deoxy-1,15-epoxy-11-hydroxy-4-0methy l-8-0-(2, 2-dimethyl-1-oxopropyl)-3-[4- inverted question mark(2,4, 6-trimethylphenyl)methyl inverted question mark-1-piperazinyl]rifamycin has been evaluated as a potential hypolipidemic agent. As part of a safety evaluation program, a 3-month oral toxicity study was performed in which CGS 24565 was administered to beagle dogs via gelatin capsules at 10, 50, or 300 mg/kg/day. Ophthalmoscopic examinations (using focal illumination and indirect opthalmoscopy) on day 83 (week 12) revealed bilateral adnexal and corneal changes affecting 5 dogs (3 males, 2 females, 300 mg/kg/day). Ophthalmoscopically, dogs from the 300 mg/kg dose level exhibited the adnexal changes characterized as ptosis, conjunctivitis, episcleritis, and relaxed membrane nictitans, while the corneal changes were characterized as posterior stromal edema (cloudy, diffuse opacity usually accompanied by deep neovascularization; the diffuse edema masked the complete evaluation of other ocular structures) and stromal infiltrates in the area of Decement's membrane (appeared to be multifocal, polymorphic changes/alterations in Decement's membrane, or endothelial swelling). No changes from normal were seen clinically in the eyes of other dogs on this experiment. In those dogs affected by the ocular changes caused by CGS 24565, a visual deficit in acuity was suspected. The corneal changes, as manifested, were suggestive of permanent, irreversible corneal damage. Subsequent ophthalmoscopic examinations performed at established intervals during weeks 15 through 26, revealed abatement of the adnexal changes, while the corneal changes, as described above, remained generally unchanged, confirming irreversibility of the corneal changes within the recovery period of 13 weeks. Light microscopy confirmed irreversible corneal neovascularization, vacuolar degeneration of the keratocytes at 300 mg/kg, and polymorphic infiltrates in the region of Decement's membrane. The results demonstrate that the cornea was the target tissue of toxicity for CGS 24565, and indicated that the findings represent a significant toxic effect. The correlation of histopathological findings support the hypothesis of the diagnosis of interstitial stromal degeneration/atrophy. The potential for a similar result to the cornea of humans does exist. Due to these changes and other toxic effects associated with this class of compound, further development was terminated. (+info)
(7/277) A simple method to evaluate the massive dose vitamin A prophylaxis program in preschool children.
A massive dose vitamin A prophylaxis program is currently in operation in several States of India. Evaluation of this program on a large scale has so far been difficult due to lack of baseline data on the prevalence of vitamin A deficiency in children. In this study, a simple evaluation method which makes use of the linear relationship that exists between age on one hand and prevalence of ocular signs of vitamin A deficiency (Bitot's spots) on the other is described. Regression coefficients between age and prevalence of vitamin A deficiency of areas not covered by the program (control areas) were found to be significantly different both from zero and from regression coefficients of regularly covered areas (experimental areas). Also, all regression lines of control areas were found to be above the regression zone of experimental areas. These differences between the experimental and control areas which were significant, indicate the impact of the program in areas where the program is in operation. The regression coefficient calculated for one area where the program was discontinued after some time was found to be significantly different from zero, also it was different from the regression zone of the experimental areas. However, the regression coefficient of the discontinued area was found to be significantly different from the experimental areas only at 10% level, indicating a lesser degree of efficiency of the program in this area as compared to regularly fed areas. It is, therefore, suggested that evaluation of the massive dose prophylaxis program be done against the null hypothesis beta = 0.0065--the regression coefficient achievable under field conditions. (+info)
(8/277) Excimer laser phototherapeutic keratectomy: indications, results and its role in the Indian scenario.
PURPOSE: To report indications, technique, and results of excimer phototherapeutic keratectomy (PTK), and describe possible reasons for the small numbers of such procedures performed in a referral institute in India. METHODS: Retrospective review of case records of 10 patients (11 eyes) who underwent excimer PTK at our institute between February 1994 and September 1997. RESULTS: Corneal scars were the most common indication for treatment. Best-corrected visual acuity (BCVA) improved in 6 eyes (mean: 2 lines of Snellen acuity). All eyes had BCVA > or = 6/12 after treatment. None of the patients experienced loss of BCVA after treatment. Unaided visual acuity improved in 3 eyes and decreased in 2 eyes. Change in spherical equivalent refraction > or = 1 diopter occurred in 77.8% of eyes after treatment. Treating central corneal scars resulted in a significant hyperopic shift in refraction. CONCLUSIONS: Excimer PTK is a safe and effective procedure for the treatment of superficial corneal opacities. Post-treatment ametropia may require further correction with optical aids. Inappropriate referrals, deep corneal scars, and cost of the procedure could have contributed to the small numbers of PTK performed at our institute. Improved understanding of procedural strengths and limitations could lead to increased use of this procedure, with satisfying results in selected patients. (+info)
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