Disorder occurring in the central or peripheral area of the cornea. The usual degree of transparency becomes relatively opaque.
The hairs which project from the edges of the EYELIDS.
A disease of the eye in which the eyelashes abnormally turn inwards toward the eyeball producing constant irritation caused by motion of the lids.
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)
Methods used to remove unwanted facial and body hair.
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)
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.
Diseases of the cornea.
The turning inward (inversion) of the edge of the eyelid, with the tarsal cartilage turned inward toward the eyeball. (Dorland, 27th ed)
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.
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.
The branch of surgery concerned with restoration, reconstruction, or improvement of defective, damaged, or missing structures.
A chronic infection of the CONJUNCTIVA and CORNEA caused by CHLAMYDIA TRACHOMATIS.
Eyelid diseases refer to various medical conditions that affect the function, structure, or appearance of the eyelids, including inflammatory, infectious, neoplastic, congenital, and traumatic disorders, which can impact vision, comfort, and overall ocular health.
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.
Diseases affecting the eye.
The lamellated connective tissue constituting the thickest layer of the cornea between the Bowman and Descemet membranes.
Partial or total replacement of all layers of a central portion of the cornea.
Simultaneous inflammation of the cornea and conjunctiva.
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.
Fibroblasts which occur in the CORNEAL STROMA.
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.
Injury to any part of the eye by extreme heat, chemical agents, or ultraviolet radiation.
'Chemical burns' is a medical term that refers to injuries resulting from skin or eye contact with harmful substances, such as acids, alkalis, or irritants, which can cause damage ranging from mild irritation to severe necrosis and scarring.
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.
The branch of philosophy dealing with the nature of the beautiful. It includes beauty, esthetic experience, esthetic judgment, esthetic aspects of medicine, etc.
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.
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.
Inflammation of the cornea.
Congenital absence of or defects in structures of the eye; may also be hereditary.
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.).
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.
The front third of the eyeball that includes the structures between the front surface of the cornea and the front of the VITREOUS BODY.
The core of the crystalline lens, surrounded by the cortex.
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)
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)
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.
Partial or total replacement of the CORNEA from one human or animal to another.
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).
Lenses designed to be worn on the front surface of the eyeball. (UMDNS, 1999)
Stratified squamous epithelium that covers the outer surface of the CORNEA. It is smooth and contains many free nerve endings.
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.
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 2.3.1.43.

Phenotype of autosomal recessive congenital microphthalmia mapping to chromosome 14q32. (1/277)

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)

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. (2/277)

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)

Functional human corneal equivalents constructed from cell lines. (3/277)

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)

Persistent corneal haze after excimer laser photokeratectomy in plasminogen-deficient mice. (4/277)

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)

Relationship between structure and biochemical phenotype of lecithin:cholesterol acyltransferase (LCAT) mutants causing fish-eye disease. (5/277)

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)

Ocular changes in beagle dogs following oral administration of CGS 24565, a potential hypolipidemic agent. (6/277)

(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)

A simple method to evaluate the massive dose vitamin A prophylaxis program in preschool children. (7/277)

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)

Excimer laser phototherapeutic keratectomy: indications, results and its role in the Indian scenario. (8/277)

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)

Corneal opacity refers to a condition in which the cornea, the clear front part of the eye, becomes cloudy or opaque. This can occur due to various reasons such as injury, infection, degenerative changes, or inherited disorders. As a result, light is not properly refracted and vision becomes blurred or distorted. In some cases, corneal opacity can lead to complete loss of vision in the affected eye. Treatment options depend on the underlying cause and may include medication, corneal transplantation, or other surgical procedures.

Eyelashes are defined in medical terms as the slender, hair-like growths that originate from the edges of the eyelids. They are made up of keratin and follicles, and their primary function is to protect the eyes from debris, sweat, and other irritants by acting as a physical barrier. Additionally, they play a role in enhancing the aesthetic appeal of the eyes and can also serve as a sensory organ, helping to detect potential threats near the eye area.

Trichiasis is a medical condition where the eyelashes are abnormally positioned and grow inward, so that they rub against the cornea or the inner surface of the eyelid. This can cause irritation, discomfort, and potentially lead to corneal abrasions, scarring, or infection if left untreated. It is often caused by inflammation, injury, or an aging process that affects the eyelids. Treatment options include epilation (removal of the lashes), electrolysis, or surgery to reposition or remove the misdirected lashes and prevent recurrence.

A cataract is a clouding of the natural lens in the eye that affects vision. This clouding can cause vision to become blurry, faded, or dim, making it difficult to see clearly. Cataracts are a common age-related condition, but they can also be caused by injury, disease, or medication use. In most cases, cataracts develop gradually over time and can be treated with surgery to remove the cloudy lens and replace it with an artificial one.

Hair removal is the deliberate elimination or reduction of body hair. This can be achieved through various methods, both temporary and permanent. Some common temporary methods include shaving, waxing, tweezing, and depilatory creams. Permanent methods may involve laser hair removal or electrolysis, which target the hair follicle to prevent future growth. It's important to note that some methods can have side effects or risks, so it's recommended to consult with a healthcare professional or dermatologist before starting any new hair removal regimen.

The cornea is the clear, dome-shaped surface at the front of the eye. It plays a crucial role in focusing vision. The cornea protects the eye from harmful particles and microorganisms, and it also serves as a barrier against UV light. Its transparency allows light to pass through and get focused onto the retina. The cornea does not contain blood vessels, so it relies on tears and the fluid inside the eye (aqueous humor) for nutrition and oxygen. Any damage or disease that affects its clarity and shape can significantly impact vision and potentially lead to blindness if left untreated.

Lecithin:cholesterol acyltransferase (LCAT) deficiency is a genetic disorder that affects the metabolism of cholesterol in the body. LCAT is an enzyme that helps to convert cholesterol into a form that can be easily transported in the bloodstream.

In LCAT deficiency, the activity of this enzyme is reduced or absent, leading to an accumulation of cholesterol in various tissues and organs of the body. This can result in a range of symptoms, including corneal opacities (clouding of the clear outer layer of the eye), hemolytic anemia (destruction of red blood cells), proteinuria (excess protein in the urine), and kidney failure.

There are two main types of LCAT deficiency: a complete form, known as fish-eye disease, which is characterized by corneal opacities but few other symptoms; and an incomplete form, known as LCAT deficiency with systemic involvement, which can affect multiple organs and systems of the body.

LCAT deficiency is caused by mutations in the LCAT gene, which provides instructions for making the LCAT enzyme. Inheritance is autosomal recessive, meaning that an individual must inherit two copies of the mutated gene (one from each parent) to develop the disorder.

Corneal diseases are a group of disorders that affect the cornea, which is the clear, dome-shaped surface at the front of the eye. The cornea plays an important role in focusing vision, and any damage or disease can cause significant visual impairment or loss. Some common types of corneal diseases include:

1. Keratoconus: A progressive disorder in which the cornea thins and bulges outward into a cone shape, causing distorted vision.
2. Fuchs' dystrophy: A genetic disorder that affects the inner layer of the cornea called the endothelium, leading to swelling, cloudiness, and decreased vision.
3. Dry eye syndrome: A condition in which the eyes do not produce enough tears or the tears evaporate too quickly, causing discomfort, redness, and blurred vision.
4. Corneal ulcers: Open sores on the cornea that can be caused by infection, trauma, or other factors.
5. Herpes simplex keratitis: A viral infection of the cornea that can cause recurrent episodes of inflammation, scarring, and vision loss.
6. Corneal dystrophies: Inherited disorders that affect the structure and clarity of the cornea, leading to visual impairment or blindness.
7. Bullous keratopathy: A condition in which the endothelium fails to pump fluid out of the cornea, causing it to swell and form blisters.
8. Corneal trauma: Injury to the cornea caused by foreign objects, chemicals, or other factors that can lead to scarring, infection, and vision loss.

Treatment for corneal diseases varies depending on the specific condition and severity of the disease. Options may include eyedrops, medications, laser surgery, corneal transplantation, or other treatments.

Entropion is a medical condition in which the eyelid, particularly the lower eyelid, turns inward or rolls in toward the eye. This can cause the eyelashes or skin to rub against the cornea, which can lead to discomfort, irritation, and potentially damage the front surface of the eye. Entropion can be caused by various factors such as aging, eye inflammation, injury, or congenital defects. Treatment typically involves surgical correction to tighten or reposition the eyelid. If left untreated, entropion may result in corneal abrasions, infections, and vision loss.

Corneal dystrophies, hereditary are a group of genetic disorders that affect the cornea, which is the clear, outermost layer at the front of the eye. These conditions are characterized by the buildup of abnormal material in the cornea, leading to decreased vision, pain, or cloudiness in the eye.

There are many different types of corneal dystrophies, each affecting a specific layer of the cornea and having its own pattern of inheritance. Some common types include:

1. Fuchs' endothelial dystrophy: This affects the inner lining of the cornea (endothelium) and causes swelling and cloudiness in the cornea. It is typically inherited in an autosomal dominant manner, meaning that a child has a 50% chance of inheriting the condition if one parent has it.
2. Granular dystrophy: This affects the stroma, which is the middle layer of the cornea. It causes the formation of opaque, grayish-white deposits in the cornea that can affect vision. It is typically inherited in an autosomal dominant or recessive manner.
3. Lattice dystrophy: This also affects the stroma and is characterized by the formation of a lattice-like pattern of fine, whitish lines in the cornea. It is typically inherited in an autosomal dominant manner.
4. Macular dystrophy: This affects the central part of the cornea (macula) and can cause cloudiness, leading to decreased vision. It is typically inherited in an autosomal recessive manner.

Treatment for corneal dystrophies may include eyedrops, medications, or surgery, depending on the severity of the condition and its impact on vision. In some cases, a corneal transplant may be necessary to restore vision.

Blindness is a condition of complete or near-complete vision loss. It can be caused by various factors such as eye diseases, injuries, or birth defects. Total blindness means that a person cannot see anything at all, while near-complete blindness refers to having only light perception or the ability to perceive the direction of light, but not able to discern shapes or forms. Legal blindness is a term used to define a certain level of visual impairment that qualifies an individual for government assistance and benefits; it usually means best corrected visual acuity of 20/200 or worse in the better eye, or a visual field no greater than 20 degrees in diameter.

Plastic surgery is a medical specialty that involves the restoration, reconstruction, or alteration of the human body. It can be divided into two main categories: reconstructive surgery and cosmetic surgery.

Reconstructive surgery is performed to correct functional impairments caused by burns, trauma, birth defects, or disease. The goal is to improve function, but may also involve improving appearance.

Cosmetic (or aesthetic) surgery is performed to reshape normal structures of the body in order to improve the patient's appearance and self-esteem. This includes procedures such as breast augmentation, rhinoplasty, facelifts, and tummy tucks.

Plastic surgeons use a variety of techniques, including skin grafts, tissue expansion, flap surgery, and fat grafting, to achieve their goals. They must have a thorough understanding of anatomy, as well as excellent surgical skills and aesthetic judgment.

Trachoma is a chronic infectious disease caused by the bacterium Chlamydia trachomatis. It primarily affects the eyes, causing repeated infections that lead to scarring of the inner eyelid and eyelashes turning inward (trichiasis), which can result in damage to the cornea and blindness if left untreated.

The disease is spread through direct contact with eye or nose discharge from infected individuals, often through contaminated fingers, shared towels, or flies that have come into contact with the discharge. Trachoma is prevalent in areas with poor sanitation and limited access to clean water, making it a significant public health issue in many developing countries.

Preventive measures include improving personal hygiene, such as washing hands regularly, promoting facial cleanliness, and providing safe water and sanitation facilities. Treatment typically involves antibiotics to eliminate the infection and surgery for advanced cases with trichiasis or corneal damage.

Eyelid diseases refer to a variety of medical conditions that affect the function and/or appearance of the eyelids. These can include structural abnormalities, such as entropion (inward turning of the eyelid) or ectropion (outward turning of the eyelid), as well as functional issues like ptosis (drooping of the upper eyelid). Other common eyelid diseases include blepharitis (inflammation of the eyelid margin), chalazion (a blocked oil gland in the eyelid), and cancerous or benign growths on the eyelid. Symptoms of eyelid diseases can vary widely, but often include redness, swelling, pain, itching, tearing, and sensitivity to light. Treatment for these conditions depends on the specific diagnosis and may range from self-care measures and medications to surgical intervention.

Tattooing is defined medically as the process of inserting pigment into the skin's dermis layer to change its color. This procedure creates a permanent design or image. The equipment used for tattooing includes an electrically powered tattoo machine, needles, and ink. Tattooing can carry potential risks such as infection, allergic reactions, and scarring. It is essential to ensure that all tattooing procedures are performed under sterile conditions and by a licensed professional to minimize these risks.

Eye diseases are a range of conditions that affect the eye or visual system, causing damage to vision and, in some cases, leading to blindness. These diseases can be categorized into various types, including:

1. Refractive errors: These include myopia (nearsightedness), hyperopia (farsightedness), astigmatism, and presbyopia, which affect the way light is focused on the retina and can usually be corrected with glasses or contact lenses.
2. Cataracts: A clouding of the lens inside the eye that leads to blurry vision, glare, and decreased contrast sensitivity. Cataract surgery is the most common treatment for this condition.
3. Glaucoma: A group of diseases characterized by increased pressure in the eye, leading to damage to the optic nerve and potential blindness if left untreated. Treatment includes medications, laser therapy, or surgery.
4. Age-related macular degeneration (AMD): A progressive condition that affects the central part of the retina called the macula, causing blurry vision and, in advanced stages, loss of central vision. Treatment may include anti-VEGF injections, laser therapy, or nutritional supplements.
5. Diabetic retinopathy: A complication of diabetes that affects the blood vessels in the retina, leading to bleeding, leakage, and potential blindness if left untreated. Treatment includes laser therapy, anti-VEGF injections, or surgery.
6. Retinal detachment: A separation of the retina from its underlying tissue, which can lead to vision loss if not treated promptly with surgery.
7. Amblyopia (lazy eye): A condition where one eye does not develop normal vision, often due to a misalignment or refractive error in childhood. Treatment includes correcting the underlying problem and encouraging the use of the weaker eye through patching or other methods.
8. Strabismus (crossed eyes): A misalignment of the eyes that can lead to amblyopia if not treated promptly with surgery, glasses, or other methods.
9. Corneal diseases: Conditions that affect the transparent outer layer of the eye, such as keratoconus, Fuchs' dystrophy, and infectious keratitis, which can lead to vision loss if not treated promptly.
10. Uveitis: Inflammation of the middle layer of the eye, which can cause vision loss if not treated promptly with anti-inflammatory medications or surgery.

The corneal stroma, also known as the substantia propria, is the thickest layer of the cornea, which is the clear, dome-shaped surface at the front of the eye. The cornea plays a crucial role in focusing vision.

The corneal stroma makes up about 90% of the cornea's thickness and is composed of parallel bundles of collagen fibers that are arranged in regular, repeating patterns. These fibers give the cornea its strength and transparency. The corneal stroma also contains a small number of cells called keratocytes, which produce and maintain the collagen fibers.

Disorders that affect the corneal stroma can cause vision loss or other eye problems. For example, conditions such as keratoconus, in which the cornea becomes thin and bulges outward, can distort vision and make it difficult to see clearly. Other conditions, such as corneal scarring or infection, can also affect the corneal stroma and lead to vision loss or other eye problems.

Penetrating keratoplasty (PK) is a type of corneal transplant surgery where the entire thickness of the host's damaged or diseased cornea is removed and replaced with a similar full-thickness portion of a healthy donor's cornea. The procedure aims to restore visual function, alleviate pain, and improve the structural integrity of the eye. It is typically performed for conditions such as severe keratoconus, corneal scarring, or corneal ulcers that cannot be treated with other, less invasive methods. Following the surgery, patients may require extended recovery time and rigorous postoperative care to minimize the risk of complications and ensure optimal visual outcomes.

Keratoconjunctivitis is a medical term that refers to the inflammation of both the cornea (the clear, outer layer at the front of the eye) and the conjunctiva (the mucous membrane that covers the inner surface of the eyelids and the white part of the eye).

The condition can cause symptoms such as redness, pain, sensitivity to light, watery eyes, and a gritty or burning sensation in the eyes. Keratoconjunctivitis can be caused by various factors, including viral or bacterial infections, allergies, or environmental irritants like dust, smoke, or chemical fumes.

Treatment for keratoconjunctivitis depends on the underlying cause of the condition and may include medications such as antibiotics, antivirals, or anti-inflammatory agents to reduce inflammation and relieve symptoms. In some cases, artificial tears or lubricants may also be recommended to help keep the eyes moist and comfortable.

Visual acuity is a measure of the sharpness or clarity of vision. It is usually tested by reading an eye chart from a specific distance, such as 20 feet (6 meters). The standard eye chart used for this purpose is called the Snellen chart, which contains rows of letters that decrease in size as you read down the chart.

Visual acuity is typically expressed as a fraction, with the numerator representing the testing distance and the denominator indicating the smallest line of type that can be read clearly. For example, if a person can read the line on the eye chart that corresponds to a visual acuity of 20/20, it means they have normal vision at 20 feet. If their visual acuity is 20/40, it means they must be as close as 20 feet to see what someone with normal vision can see at 40 feet.

It's important to note that visual acuity is just one aspect of overall vision and does not necessarily reflect other important factors such as peripheral vision, depth perception, color vision, or contrast sensitivity.

Corneal keratocytes are specialized cells located within the stroma, which is the thickest layer of the cornea, which is the clear front "window" of the eye. These cells play a crucial role in maintaining the transparency and structural integrity of the cornea. Keratocytes are star-shaped cells that produce and maintain the extracellular matrix (ECM) of the corneal stroma, which consists mainly of collagen fibrils and proteoglycans.

In a healthy cornea, keratocytes exist in a quiescent state, but they can become activated and undergo phenotypic changes in response to injury or disease. Activated keratocytes can differentiate into fibroblasts or myofibroblasts, which participate in the wound healing process by synthesizing ECM components and contracting to help close wounds. However, an overactive or dysregulated wound healing response can lead to corneal opacity, scarring, and visual impairment.

Therefore, understanding the behavior and regulation of corneal keratocytes is essential for developing effective therapies and treatments for various corneal disorders and diseases.

A pupil disorder refers to any abnormality or condition affecting the size, shape, or reactivity of the pupils, the circular black openings in the center of the eyes through which light enters. The pupil's primary function is to regulate the amount of light that reaches the retina, adjusting its size accordingly.

There are several types of pupil disorders, including:

1. Anisocoria: A condition characterized by unequal pupil sizes in either one or both eyes. This may be caused by various factors, such as nerve damage, trauma, inflammation, or medication side effects.

2. Horner's syndrome: A neurological disorder affecting the autonomic nervous system, resulting in a smaller pupil (miosis), partial eyelid droop (ptosis), and decreased sweating (anhidrosis) on the same side of the face. It is caused by damage to the sympathetic nerve pathway.

3. Adie's tonic pupil: A condition characterized by a dilated, poorly reactive pupil due to damage to the ciliary ganglion or short ciliary nerves. This disorder usually affects one eye and may be associated with decreased deep tendon reflexes in the affected limbs.

4. Argyll Robertson pupil: A condition where the pupils are small, irregularly shaped, and do not react to light but constrict when focusing on nearby objects (accommodation). This disorder is often associated with neurosyphilis or other brainstem disorders.

5. Pupillary dilation: Abnormally dilated pupils can be a sign of various conditions, such as drug use (e.g., atropine, cocaine), brainstem injury, Adie's tonic pupil, or oculomotor nerve palsy.

6. Pupillary constriction: Abnormally constricted pupils can be a sign of various conditions, such as Horner's syndrome, Argyll Robertson pupil, drug use (e.g., opioids, pilocarpine), or oculomotor nerve palsy.

7. Light-near dissociation: A condition where the pupils do not react to light but constrict when focusing on nearby objects. This can be seen in Argyll Robertson pupil and Adie's tonic pupil.

Prompt evaluation by an ophthalmologist or neurologist is necessary for accurate diagnosis and management of these conditions.

Eye burns typically refer to injuries or damage to the eyes caused by exposure to harmful substances, extreme temperatures, or radiation. This can result in a variety of symptoms, including redness, pain, tearing, swelling, and blurred vision.

Chemical eye burns can occur when the eyes come into contact with strong acids, alkalis, or other irritants. These substances can cause damage to the cornea, conjunctiva, and other structures of the eye. The severity of the burn will depend on the type and concentration of the chemical, as well as the length of time it was in contact with the eye.

Thermal eye burns can result from exposure to hot or cold temperatures, such as steam, flames, or extreme cold. These types of burns can cause damage to the surface of the eye and may require medical attention to prevent further complications.

Radiation eye burns can occur after exposure to high levels of ultraviolet (UV) light, such as from welding torches, sun lamps, or tanning beds. Prolonged exposure to these sources can cause damage to the cornea and other structures of the eye, leading to symptoms like pain, redness, and sensitivity to light.

If you experience symptoms of an eye burn, it is important to seek medical attention as soon as possible. Treatment may include flushing the eyes with water or saline solution, administering medication to relieve pain and inflammation, or in severe cases, surgery to repair damaged tissue.

Chemical burns are a type of tissue injury that results from exposure to strong acids, bases, or other corrosive chemicals. These substances can cause damage by reacting chemically with the skin or other tissues, leading to destruction of cells and potentially serious harm. The severity of a chemical burn depends on several factors, including the type and concentration of the chemical, the duration of exposure, and the amount of body surface area affected.

Chemical burns can occur through direct contact with the skin or eyes, inhalation of toxic fumes, or ingestion of harmful substances. Symptoms may include redness, pain, blistering, swelling, and irritation at the site of contact. In severe cases, chemical burns can lead to scarring, disability, or even death.

Immediate medical attention is required for chemical burns, as they can continue to cause damage until the source of the injury is removed, and appropriate first aid measures are taken. Treatment typically involves thorough cleaning and irrigation of the affected area, followed by administration of pain medication and other supportive care as needed. In some cases, skin grafting or other surgical interventions may be required to promote healing and minimize scarring.

Photorefractive Keratectomy (PRK) is a type of refractive surgery used to correct vision issues such as nearsightedness, farsightedness, and astigmatism. It works by reshaping the cornea using a laser, which alters how light enters the eye and focuses on the retina.

In PRK, the surgeon removes the thin outer layer of the cornea (epithelium) with an alcohol solution or a blunt surgical instrument before using the laser to reshape the underlying stromal layer. The epithelium then grows back during the healing process, which can take several days.

Compared to LASIK (another type of refractive surgery), PRK has a longer recovery time and may cause more discomfort in the first few days after surgery. However, it is an option for people who are not good candidates for LASIK due to thin corneas or other eye conditions.

It's important to note that while refractive surgeries like PRK can significantly improve vision and reduce dependence on glasses or contact lenses, they may not completely eliminate the need for corrective eyewear in all cases. Additionally, as with any surgical procedure, there are potential risks and complications associated with PRK, including infection, dry eye, and visual disturbances such as glare or halos around lights.

"Esthetics" is a term that refers to the branch of knowledge dealing with the principles of beauty and artistic taste, particularly as they relate to the appreciation of beauty in the visual arts. However, it is important to note that "esthetics" is not typically used as a medical term.

In the context of healthcare and medicine, the term that is more commonly used is "aesthetics," which refers to the study and theory of beauty and taste, but in relation to medical treatments or procedures that aim to improve or restore physical appearance. Aesthetic medicine includes procedures such as cosmetic surgery, dermatology, and other treatments aimed at enhancing or restoring physical appearance for reasons that are not related to medical necessity.

Therefore, the term "esthetics" is more appropriately used in the context of art, beauty, and culture rather than medicine.

Acoustic microscopy is a non-invasive imaging technique that uses sound waves to visualize and analyze the structure and properties of various materials, including biological samples. In the context of medical diagnostics and research, acoustic microscopy can be used to examine tissues, cells, and cellular components with high resolution, providing valuable information about their mechanical and physical properties.

In acoustic microscopy, high-frequency sound waves are focused onto a sample using a transducer. The interaction between the sound waves and the sample generates echoes, which contain information about the sample's internal structure and properties. These echoes are then recorded and processed to create an image of the sample.

Acoustic microscopy offers several advantages over other imaging techniques, such as optical microscopy or electron microscopy. For example, it does not require staining or labeling of samples, which can be time-consuming and potentially damaging. Additionally, acoustic microscopy can provide high-resolution images of samples in their native state, allowing researchers to study the effects of various treatments or interventions on living cells and tissues.

In summary, acoustic microscopy is a non-invasive imaging technique that uses sound waves to visualize and analyze the structure and properties of biological samples with high resolution, providing valuable information for medical diagnostics and research.

Corneal neovascularization is a medical condition that refers to the growth of new, abnormal blood vessels in the cornea, which is the clear, dome-shaped surface at the front of the eye. The cornea typically receives its nutrients from tears and oxygen in the air, so it does not have its own blood vessels. However, when the cornea is damaged or inflamed, it may trigger the growth of new blood vessels from the surrounding tissue into the cornea to promote healing.

Corneal neovascularization can occur due to various eye conditions such as infection, injury, inflammation, degenerative diseases, or contact lens wear. Excessive growth of blood vessels in the cornea can interfere with vision, cause scarring, and increase the risk of corneal transplant rejection. Treatment for corneal neovascularization depends on the underlying cause and may include topical medications, surgery, or other therapies to reduce inflammation, prevent further growth of blood vessels, and preserve vision.

Keratitis is a medical condition that refers to inflammation of the cornea, which is the clear, dome-shaped surface at the front of the eye. The cornea plays an essential role in focusing vision, and any damage or infection can cause significant visual impairment. Keratitis can result from various causes, including bacterial, viral, fungal, or parasitic infections, as well as trauma, allergies, or underlying medical conditions such as dry eye syndrome. Symptoms of keratitis may include redness, pain, tearing, sensitivity to light, blurred vision, and a feeling of something foreign in the eye. Treatment for keratitis depends on the underlying cause but typically includes antibiotics, antivirals, or anti-fungal medications, as well as measures to alleviate symptoms and promote healing.

Eye abnormalities refer to any structural or functional anomalies that affect the eye or its surrounding tissues. These abnormalities can be present at birth (congenital) or acquired later in life due to various factors such as injury, disease, or aging. Some examples of eye abnormalities include:

1. Strabismus: Also known as crossed eyes, strabismus is a condition where the eyes are misaligned and point in different directions.
2. Nystagmus: This is an involuntary movement of the eyes that can be horizontal, vertical, or rotatory.
3. Cataracts: A cataract is a clouding of the lens inside the eye that can cause vision loss.
4. Glaucoma: This is a group of eye conditions that damage the optic nerve and can lead to vision loss.
5. Retinal disorders: These include conditions such as retinal detachment, macular degeneration, and diabetic retinopathy.
6. Corneal abnormalities: These include conditions such as keratoconus, corneal ulcers, and Fuchs' dystrophy.
7. Orbital abnormalities: These include conditions such as orbital tumors, thyroid eye disease, and Graves' ophthalmopathy.
8. Ptosis: This is a condition where the upper eyelid droops over the eye.
9. Color blindness: A condition where a person has difficulty distinguishing between certain colors.
10. Microphthalmia: A condition where one or both eyes are abnormally small.

These are just a few examples of eye abnormalities, and there are many others that can affect the eye and its functioning. If you suspect that you have an eye abnormality, it is important to consult with an ophthalmologist for proper diagnosis and treatment.

Low vision is a term used to describe significant visual impairment that cannot be corrected with standard glasses, contact lenses, medication or surgery. It is typically defined as visual acuity of less than 20/70 in the better-seeing eye after best correction, or a visual field of less than 20 degrees in the better-seeing eye.

People with low vision may have difficulty performing everyday tasks such as reading, recognizing faces, watching television, driving, or simply navigating their environment. They may also experience symptoms such as sensitivity to light, glare, or contrast, and may benefit from the use of visual aids, assistive devices, and rehabilitation services to help them maximize their remaining vision and maintain their independence.

Low vision can result from a variety of causes, including eye diseases such as macular degeneration, diabetic retinopathy, glaucoma, or cataracts, as well as congenital or inherited conditions, brain injuries, or aging. It is important for individuals with low vision to receive regular eye examinations and consult with a low vision specialist to determine the best course of treatment and management.

Keratan sulfate is a type of glycosaminoglycan (GAG), which is a complex carbohydrate found in connective tissues, including the cornea and cartilage. It is composed of repeating disaccharide units of galactose and N-acetylglucosamine, with sulfate groups attached to some of the sugar molecules.

Keratan sulfate is unique among GAGs because it contains a high proportion of non-sulfated sugars and is often found covalently linked to proteins in structures called proteoglycans. In the cornea, keratan sulfate plays important roles in maintaining transparency and regulating hydration. In cartilage, it contributes to the elasticity and resilience of the tissue.

Abnormalities in keratan sulfate metabolism have been associated with several genetic disorders, including corneal dystrophies and skeletal dysplasias.

The anterior eye segment refers to the front portion of the eye, which includes the cornea, iris, ciliary body, and lens. The cornea is the clear, dome-shaped surface at the front of the eye that refracts light entering the eye and provides protection. The iris is the colored part of the eye that controls the amount of light reaching the retina by adjusting the size of the pupil. The ciliary body is a muscle that changes the shape of the lens to focus on objects at different distances. The lens is a transparent structure located behind the iris that further refracts light to provide a clear image. Together, these structures work to focus light onto the retina and enable vision.

The lens nucleus, also known as the crystalline lens nucleus, is the central part of the crystalline lens in the eye. The crystalline lens is a biconvex structure located behind the iris and pupil, which helps to refract (bend) light rays and focus them onto the retina.

The lens nucleus is composed of densely packed lens fibers that have lost their nuclei and cytoplasm during differentiation. It is surrounded by the lens cortex, which consists of younger lens fiber cells that are still metabolically active. The lens nucleus is relatively avascular and receives its nutrients through diffusion from the aqueous humor in the anterior chamber of the eye.

The lens nucleus plays an important role in the accommodation process, which allows the eye to focus on objects at different distances. During accommodation, the ciliary muscles contract and release tension on the lens zonules, allowing the lens to become thicker and increase its curvature. This results in a decrease in the focal length of the lens and enables the eye to focus on nearby objects. The lens nucleus is more rigid than the cortex and helps maintain the shape of the lens during accommodation.

Changes in the lens nucleus are associated with several age-related eye conditions, including cataracts and presbyopia. Cataracts occur when the lens becomes cloudy or opaque, leading to a decrease in vision clarity. Presbyopia is a condition that affects the ability to focus on near objects and is caused by a hardening of the lens nucleus and a loss of elasticity in the lens fibers.

Herpetic keratitis is a specific type of keratitis (inflammation of the cornea) that is caused by herpes simplex virus (HSV) infection. It is further divided into two types: dendritic and disciform keratitis. Dendritic keratitis is characterized by the development of branching ulcers on the surface of the cornea, while disciform keratitis involves inflammation and opacity in the stroma (middle layer) of the cornea. Both types of herpetic keratitis can cause symptoms such as eye pain, redness, sensitivity to light, tearing, and blurred vision. If left untreated, herpetic keratitis can lead to serious complications, including blindness.

An excimer laser is a type of laser that is used in various medical procedures, particularly in ophthalmology and dermatology. The term "excimer" is derived from "excited dimer," which refers to a short-lived molecule formed when two atoms combine in an excited state.

Excimer lasers emit light at a specific wavelength that is determined by the type of gas used in the laser. In medical applications, excimer lasers typically use noble gases such as argon, krypton, or xenon, combined with halogens such as fluorine or chlorine. The most commonly used excimer laser in medical procedures is the excimer laser that uses a mixture of argon and fluoride gas to produce light at a wavelength of 193 nanometers (nm).

In ophthalmology, excimer lasers are primarily used for refractive surgery, such as LASIK and PRK, to correct vision problems like myopia, hyperopia, and astigmatism. The laser works by vaporizing tiny amounts of tissue from the cornea, reshaping its curvature to improve the way light is focused onto the retina.

In dermatology, excimer lasers are used for various skin conditions, including psoriasis, vitiligo, and atopic dermatitis. The laser works by emitting high-energy ultraviolet (UV) light that selectively targets and destroys the abnormal cells responsible for these conditions while leaving surrounding healthy tissue intact.

Excimer lasers are known for their precision, accuracy, and minimal side effects, making them a popular choice in medical procedures where fine detail and tissue preservation are critical.

The crystalline lens in the eye is composed of three main parts: the capsule, the cortex, and the nucleus. The lens cortex is the outer layer of the lens, located between the capsule and the nucleus. It is made up of proteins and water, and its primary function is to help refract (bend) light rays as they pass through the eye, contributing to the focusing power of the eye.

The cortex is more flexible than the central nucleus, allowing it to change shape and adjust the focus of the eye for different distances. However, with age, the lens cortex can become less elastic, leading to presbyopia, a common age-related condition that affects the ability to focus on close objects. Additionally, changes in the lens cortex have been associated with cataracts, a clouding of the lens that can impair vision.

Corneal transplantation, also known as keratoplasty, is a surgical procedure in which all or part of a damaged or diseased cornea is replaced with healthy corneal tissue from a deceased donor. The cornea is the clear, dome-shaped surface at the front of the eye that plays an important role in focusing vision. When it becomes cloudy or misshapen due to injury, infection, or inherited conditions, vision can become significantly impaired.

During the procedure, the surgeon carefully removes a circular section of the damaged cornea and replaces it with a similarly sized piece of donor tissue. The new cornea is then stitched into place using very fine sutures that are typically removed several months after surgery.

Corneal transplantation has a high success rate, with more than 90% of procedures resulting in improved vision. However, as with any surgical procedure, there are risks involved, including infection, rejection of the donor tissue, and bleeding. Regular follow-up care is essential to monitor for any signs of complications and ensure proper healing.

Vision disorders refer to a wide range of conditions that affect the visual system and result in various symptoms, such as blurry vision, double vision, distorted vision, impaired depth perception, and difficulty with visual tracking or focusing. These disorders can be categorized into several types, including:

1. Refractive errors: These occur when the shape of the eye prevents light from focusing directly on the retina, resulting in blurry vision. Examples include myopia (nearsightedness), hyperopia (farsightedness), astigmatism, and presbyopia (age-related loss of near vision).
2. Strabismus: Also known as crossed eyes or walleye, strabismus is a misalignment of the eyes where they point in different directions, which can lead to double vision or loss of depth perception.
3. Amblyopia: Often called lazy eye, amblyopia is a condition where one eye has reduced vision due to lack of proper visual development during childhood. It may be caused by strabismus, refractive errors, or other factors that interfere with normal visual development.
4. Accommodative disorders: These involve problems with the focusing ability of the eyes, such as convergence insufficiency (difficulty focusing on close objects) and accommodative dysfunction (inability to maintain clear vision at different distances).
5. Binocular vision disorders: These affect how the eyes work together as a team, leading to issues like poor depth perception, eye strain, and headaches. Examples include convergence insufficiency, divergence excess, and suppression.
6. Ocular motility disorders: These involve problems with eye movement, such as nystagmus (involuntary eye movements), strabismus, or restricted extraocular muscle function.
7. Visual processing disorders: These affect the brain's ability to interpret and make sense of visual information, even when the eyes themselves are healthy. Symptoms may include difficulty with reading, recognizing shapes and objects, and understanding spatial relationships.
8. Low vision: This term refers to significant visual impairment that cannot be fully corrected with glasses, contact lenses, medication, or surgery. It includes conditions like macular degeneration, diabetic retinopathy, glaucoma, and cataracts.
9. Blindness: Complete loss of sight in both eyes, which can be caused by various factors such as injury, disease, or genetic conditions.

Contact lenses are thin, curved plastic or silicone hydrogel devices that are placed on the eye to correct vision, replace a missing or damaged cornea, or for cosmetic purposes. They rest on the surface of the eye, called the cornea, and conform to its shape. Contact lenses are designed to float on a thin layer of tears and move with each blink.

There are two main types of contact lenses: soft and rigid gas permeable (RGP). Soft contact lenses are made of flexible hydrophilic (water-absorbing) materials that allow oxygen to pass through the lens to the cornea. RGP lenses are made of harder, more oxygen-permeable materials.

Contact lenses can be used to correct various vision problems, including nearsightedness, farsightedness, astigmatism, and presbyopia. They come in different shapes, sizes, and powers to suit individual needs and preferences. Proper care, handling, and regular check-ups with an eye care professional are essential for maintaining good eye health and preventing complications associated with contact lens wear.

The corneal epithelium is the outermost layer of the cornea, which is the clear, dome-shaped surface at the front of the eye. It is a stratified squamous epithelium, consisting of several layers of flat, scale-like cells that are tightly packed together. The corneal epithelium serves as a barrier to protect the eye from microorganisms, dust, and other foreign particles. It also provides a smooth surface for the refraction of light, contributes to the maintenance of corneal transparency, and plays a role in the eye's sensitivity to touch and pain. The corneal epithelium is constantly being renewed through the process of cell division and shedding, with new cells produced by stem cells located at the limbus, the border between the cornea and the conjunctiva.

The eye is the organ of sight, primarily responsible for detecting and focusing on visual stimuli. It is a complex structure composed of various parts that work together to enable vision. Here are some of the main components of the eye:

1. Cornea: The clear front part of the eye that refracts light entering the eye and protects the eye from harmful particles and microorganisms.
2. Iris: The colored part of the eye that controls the amount of light reaching the retina by adjusting the size of the pupil.
3. Pupil: The opening in the center of the iris that allows light to enter the eye.
4. Lens: A biconvex structure located behind the iris that further refracts light and focuses it onto the retina.
5. Retina: A layer of light-sensitive cells (rods and cones) at the back of the eye that convert light into electrical signals, which are then transmitted to the brain via the optic nerve.
6. Optic Nerve: The nerve that carries visual information from the retina to the brain.
7. Vitreous: A clear, gel-like substance that fills the space between the lens and the retina, providing structural support to the eye.
8. Conjunctiva: A thin, transparent membrane that covers the front of the eye and the inner surface of the eyelids.
9. Extraocular Muscles: Six muscles that control the movement of the eye, allowing for proper alignment and focus.

The eye is a remarkable organ that allows us to perceive and interact with our surroundings. Various medical specialties, such as ophthalmology and optometry, are dedicated to the diagnosis, treatment, and management of various eye conditions and diseases.

Phosphatidylcholine-Sterol O-Acyltransferase (PCOAT, also known as Sterol O-Acyltransferase 1 or SOAT1) is an enzyme that plays a crucial role in the regulation of cholesterol metabolism. It is located in the endoplasmic reticulum and is responsible for the transfer of acyl groups from phosphatidylcholine to cholesterol, forming cholesteryl esters. This enzymatic reaction results in the storage of excess cholesterol in lipid droplets, preventing its accumulation in the cell membrane and potentially contributing to the development of atherosclerosis if not properly regulated.

Defects or mutations in PCOAT can lead to disruptions in cholesterol homeostasis, which may contribute to various diseases such as cardiovascular disorders, metabolic syndrome, and neurodegenerative conditions. Therefore, understanding the function and regulation of this enzyme is essential for developing therapeutic strategies aimed at managing cholesterol-related disorders.

... corneal opacity is graded as nebular, macular and leucomatous. Nebular corneal opacity is a faint opacity which results due to ... Dense corneal opacities may occur in trisomy 8 mosaicism. Farber's disease: Nodular corneal opacity may be seen in association ... Macular corneal opacity is a semidense opacity produced when scarring involves about half the corneal stroma. Leucomatous ... and macular corneal dystrophy is clinically manifested as corneal opacity. The term corneal blindness is commonly used to ...
LCAT deficiency can cause impaired vision due to cholesterol corneal opacities, anemia, and kidney damage. It belongs to the ... Cogan DG, Kruth HS, Datilis MB, Martin N (1993). "Corneal opacity in LCAT disease". Cornea. 11 (6): 595-9. doi:10.1097/00003226 ...
KeraRing and INTACS intrastromal corneal ring segments 17. Phototherapeutic keratectomy for correction of corneal opacities 18 ... He has also completed numerous post-graduate training courses in North America and Europe on the latest methods of corneal ... Posterior corneal grafting using the Melles, PLK, DSAEK, DMEK, and DWAK techniques 9. Automated lamellar therapeutic ...
Filatov treated corneal opacity by human cornea transplantation. At the first, transplantation material was taken from humans ... the method also cured a number of diseases not connected to corneal opacity. He suggested that a piece of tissue placed in ... First corneal transplantation was attempted by Filatov on 28 February 1912, but the graft grew opaque. After numerous attempts ... RamĂ³n Castroviejo - a Spanish contemporary of Filatov that was also a pioneer in corneal transplantation. David Bushmich - an ...
Usually, the need for this alteration stems from corneal opacity. Corneal opacities (scarring of the cornea that creates an ... Corneal opacities are the leading reason for undergoing cosmetic tattooing. The leading reason for corneal tattooing is to ... the process is extremely successful and reduces the cosmetic disruption of any corneal opacity. Corneal tattooing may also ... "Tattooing of Corneal Opacity with Gold and Platinum Chloride." British Journal of Ophthalmology. 419-425. Doggart, James H. " ...
Cataracts and cloudiness of the cornea (corneal opacity) are common. The loss of and damage to the nerves of the optic nerve, ...
Corneal opacity that results from hereditary dystrophies is usually symmetric. Corneal enlargement may result from megalocornea ... Buphthalmos and Haab's striae can often be seen in case of congenital glaucoma.[citation needed] Corneal cloudiness may have ... The typical infant who has congenital glaucoma usually is initially referred to an ophthalmologist because of apparent corneal ... The commonly described triad of epiphora (excessive tearing), blepharospasm and photophobia may be missed until the corneal ...
High-speed optical coherence tomography of corneal opacities. Ophthalmology. 2007 Jul;114(7):1278-85. Plesea et al. Direct ... corneal elevation measurements using multiple delay en face optical coherence tomography. J Biomed Opt. 2008 Sep-Oct;13(5): ... have demonstrated the ability of OCT systems to depict pathology within the cornea as well as disorders of corneal topography. ...
Corneal abnormalities including edema or opacities ("corneal haze") Corneal staining Pupil abormalities including abormal pupil ... usually from corneal edema, or they may be localized in the case of corneal ulcer or keratitis. Corneal epithelial disruptions ... In rare instances, this opacity is congenital. In some, there is a family history of corneal growth disorders which may be ... Rezende RA, Uchoa UB, Uchoa R, Rapuano CJ, Laibson PR, Cohen EJ (2004). "Congenital corneal opacities in a cornea referral ...
Corneal opacities may be present but do not affect vision. Cryptorchidism is reported in some individuals. Individuals with XLI ...
In the treatise Ueber die Hornhautflecken, he gave an early account of corneal opacity. With Karl Ferdinand von Gräfe (1787- ...
... corneal dystrophies should be suspected when corneal transparency is lost or corneal opacities occur spontaneously, ... of lattice corneal dystrophy Granular corneal dystrophy, type 1 Granular corneal dystrophy, type 2 Macular corneal dystrophy ... Lattice corneal dystrophy Granular corneal dystrophy Macular corneal dystrophy Schnyder crystalline corneal dystrophy ... Lisch epithelial corneal dystrophy is characterized by feather shaped opacities and microcysts in the corneal epithelium that ...
The common indications for PTK are corneal dystrophies, scars, opacities, and bullous keratopathy. [PTK in the developing world ... PTK allows the removal of superficial corneal opacities and surface irregularities. It is similar to photorefractive ... http://www.ophthalmologyweb.com/JournalUpdates.aspx?spid=23&jid=15009 "Facts About The Cornea and Corneal Disease" - National ...
Recurrent corneal erosions may precede the corneal opacities and even appear in individuals lacking recognizable stromal ... Lattice corneal dystrophy type is a rare form of corneal dystrophy. It has no systemic manifestations, unlike the other type of ... Lattice corneal dystrophy has three types: type I: with no systemic association. It is caused by mutations in TGFBI gene ... Lattice corneal dystrophy was first described by Swiss ophthalmologist Hugo Biber in 1890. Lattice dystrophy gets its name from ...
Inappetence Corneal opacity - conjunctivitis Nervous signs - fits and convulsions Dog sitting position Fever Increased returns ... It also causes reproductive failure in adult pigs, and rarely identifies with corneal opacity, an eye disorder characterized by ... Stephan, H.; Gay, G.; Ramirez, T. (2 January 1988). "Encephalomyelitis, reproductive failure and corneal opacity (blue eye) in ...
Corneal diseases Corneal dystrophy is a condition characterized by bilateral, noninflammatory opacity of the cornea. It appears ... Corneal dystrophy can also have a crystalline appearance. Corneal ulcer, or ulcerative keratitis, is an inflammatory condition ... Other eye conditions can cause corneal ulcers, such as entropion, distichia, corneal dystrophy, and keratoconjunctivitis sicca ... Lens diseases Cataracts* are an opacity in the lens of the eye. Most cataracts in dogs are caused by a genetic predisposition, ...
... skin fragility and corneal opacity in the absence of lumican". The Journal of Cell Biology. 141 (5): 1277-86. doi:10.1083/jcb. ... Rada JA, Cornuet PK, Hassell JR (Jun 1993). "Regulation of corneal collagen fibrillogenesis in vitro by corneal proteoglycan ( ... Corneal transparency is possible due to the exact alignment of collagen fibers by lumican (and keratocan) in the intrafibrillar ... Mice that have the lumican gene knocked out (Lum-/-) develop opacities of the cornea in both eyes and fragile skin. The lumican ...
It can lead to corneal ulceration and permanent loss of vision due to corneal opacity. Normally, corneal surface is kept moist ... This will lead to corneal epithelial damage. Both tear film and corneal epithelium play significant role in corneal protective ... If corneal ulcer is detected, it may be treated medically with antibiotics. If corneal perforation has occurred, immediate ... Punctate epithelial defects, epithelial break down and stromal melting may be seen in corneal examination. Corneal ulceration ...
Characterized by discrete grey opacities scattered over the surface of the cornea. "Groenouw Type II": Macular type of corneal ... Later on, his findings on corneal dystrophy were classified as two separate syndromes: "Groenouw Type I": Granular type of ... In 1890 Groenouw described two different types of corneal dystrophy, of which he wrote about in an article titled " ... "Immunohistochemistry and Electron Microscopy of Early-Onset Fuchs Corneal Dystrophy in Three Cases with the Same L450W Col8A2 ...
Corneal opacity (CO)-Corneal opacity blurring part of the pupil margin Although trachoma was eliminated from much of the ... This can lead to corneal opacities and scarring and then to blindness. Linear scars present in the sulcus subtarsalis are ... The most important complication to look out for is a corneal ulcer, which is caused by intense rubbing of the affected eye, or ... Retrieved 21 April 2023.[unreliable source?] Feibel, Robert M. (1 May 2014). "Herbert Herbert: His Corneal Pits and Scleral ...
This cloudiness, or opacity, causes the corneal epithelium to become elevated, which leads to corneal opacities. The corneal ... The opacity elevates the corneal epithelium, eventually leading to corneal erosions that prompt attacks of ocular hyperemia, ... With time, the corneal changes progress into opacities in Bowman's layer, which gradually becomes more irregular and more dense ... Reis-BĂ¼cklers corneal dystrophy is a disease of the eye, a rare corneal dystrophy of unknown cause, in which the Bowman's layer ...
Nonprogressive corneal dystrophy Fine punctate corneal opacities Episodic foreign body sensation Increased tear production Eye ... Under magnification, corneal changes consisting of punctate opacities in the epithelium are found. Occasionally, these are ... Meesmann corneal dystrophy (MECD) is a rare hereditary autosomal dominant disease that is characterized as a type of corneal ... Patients with Meesmann corneal dystrophy may remain asymptomatic or experience mild symptoms. Symptoms of Meesmann corneal ...
Pathology includes anorexia, dyspnea, corneal opacity, nasal discharge, frothy nasal discharge, diarrhea, pulmonary edema, ...
Animals of both sex also had corneal opacity and spinal abnormalities (including scoliosis and fusion of vertebral arches). ...
Macular cherry-red spots in 50% by 6-10 months; corneal opacities in some Facial dysmorphology: frontal bossing, wide nasal ... corneal clouding in some patients, and dystonia (sustained muscle contractions that cause twisting and repetitive movements or ...
... corneal opacity, and ulceration. This disease is highly contagious and occurs worldwide. Younger animals are more susceptible, ... UV light also directly damages the corneal epithelium, leading to a breakdown in host innate immunity. Dust, dried-up plants, ... Anti-inflammatory therapy can help shorten recovery times, but topical corticosteroids should be used with care if corneal ... and corneal ulceration. Cattle show signs of pain, increased lacrimation, excessive blinking, and conjunctivitis. More severe ...
Cells in the cornea accumulate cholesterol and phosopholipid deposits leading to the opacity, in severe cases requiring corneal ... Schnyder crystalline corneal dystrophy (SCD) is a rare form of corneal dystrophy. It is caused by heterozygous mutations in ...
The main features of this disease are bilateral or unilateral gray band-shaped and feathery opacities. They sometimes take on a ... Lisch epithelial corneal dystrophy (LECD), also known as band-shaped and whorled microcystic dystrophy of the corneal ... "Lisch corneal dystrophy is genetically distinct from Meesmann corneal dystrophy and maps to xp22.3". Am. J. Ophthalmol. 130 (4 ... Epithelial cells in the zones of opacity were shown to have diffuse cytoplasmic vacuoles with as yet unestablished content.[ ...
The opacities may be associated with decreased visual acuity, but they have not been severe enough to need corneal ... to central corneal stromal opacities. Approximately 50 known cases have been reported in the literature. The disease so far has ... dark patches in the corneal endothelium, thought to represent patchy corneal endothelial swelling. The endothelium appears ... Some patients have found more benefit from an oral NSAID.[citation needed] The repeated corneal inflammation over time can lead ...
April 2008). "Clinical variability of autosomal dominant cataract, microcornea and corneal opacity and novel mutation in the ... 786 A cataract is an opacity that develops in the crystalline lens of the eye. The word cataract literally means, "curtain of ... so the term may have been used metaphorically to describe the similar appearance between mature ocular opacities and water fall ...
... corneal opacity is graded as nebular, macular and leucomatous. Nebular corneal opacity is a faint opacity which results due to ... Dense corneal opacities may occur in trisomy 8 mosaicism. Farbers disease: Nodular corneal opacity may be seen in association ... Macular corneal opacity is a semidense opacity produced when scarring involves about half the corneal stroma. Leucomatous ... and macular corneal dystrophy is clinically manifested as corneal opacity. The term corneal blindness is commonly used to ...
Corneal Opacity: Disorder occurring in the central or peripheral area of the cornea. The usual degree of transparency becomes ... Corneal Opacity. Subscribe to New Research on Corneal Opacity Disorder occurring in the central or peripheral area of the ... related to Corneal Opacity: 1. CosmeticsIBA 06/01/2015 - "Cosmetic outcomes improved in view of corneal opacity and ... "Intravenous vitamin C reduced the corneal opacity size more than oral vitamin C (P = 0.043). ". 11/01/2014 - " corneal opacity ...
UMSCs prevent corneal opacity after wounding. Given the therapeutic efficacy of UMSCs in treating congenital corneal opacity, ... The UMSCs were unable to correct the corneal opacity, as the cells were unable to reach the corneal stroma, due to the corneal ... weeks of age for the congenital corneal opacity studies. Male and female mice were used. For the acquired corneal opacity ... we set out to determine the ability of these cells to treat acquired corneal opacity. To generate corneal opacity, a ...
Synonyms (terms occurring on more labels are shown first): corneal opacity, corneal opacities, corneal clouding More ... Corneal opacity. Definition: clouding that can occur in the transparent part of the coat of the eyeball or cornea, secondary to ...
Dense corneal opacities may occur in trisomy 8 mosaicism.[25]. *Farbers disease: Nodular corneal opacity may be seen in ... Macular corneal opacity. It is a semi-dense opacity produced when scarring involves about half the corneal stroma.[4] ... Pediatric corneal opacities may be congenital or acquired. Congenital corneal opacities. Congenital reasons for this condition ... and macular corneal dystrophy is clinically manifested as corneal opacity.[2] The term "corneal blindness" is commonly used to ...
Corneal opacity is a disorder of the cornea that occur due to scarring or clouding of the normally clear and transparent cornea ... Corneal Opacity. Definition. Corneal opacity is a disorder of the cornea that occur due to scarring or clouding of the normally ... Risk Factors of Corneal Opacity. Although there are so many reasons or eye disorders that can lead to corneal opacity but still ... Diagnosis of Corneal opacity. Diagnosis of corneal opacity requires complete medical history and a thorough eye examination by ...
Corneal opacity is scarring of the cornea. The cornea is the clear front layer of the eye. ... Corneal opacity is caused by infection, injury, or swelling of the eye. ... Dohlman TH, Yin J, Dana R. Methods for Assessing Corneal Opacity. Semin Ophthalmol. 2019;34(4):205-210. ... www.aao.org/topic-detail/congenital-corneal-opacities-europe. ... Symptoms of corneal opacity may include:. *Vision decrease or ...
Corneal Opacity. Corneal opacity is the medical condition occurring when corneal clarity is lost. It appears as loss of ... Factors that can cause corneal opacity include corneal infection, injury, and edema [138,139]. Depending on the etiology, ... Dohlman, T.H.; Yin, J.; Dana, R. Methods for Assessing Corneal Opacity. Semin. Ophthalmol. 2019, 34, 205-210. [Google Scholar ... I) Slit lamp image of a granular cornea dystrophy from a patient with corneal opacities. AMD: age-related macular degeneration ...
Corneal Opacities. Dogs receiving oral sumatriptan developed corneal opacities and defects in the corneal epithelium. Corneal ... Corneal Opacities. Sumatriptan causes corneal opacities and defects in the corneal epithelium in dogs; this raises the ... Defects in the corneal epithelium were noted in a 60-week study. Earlier examinations for these toxicities were not conducted ... There is evidence of alterations in corneal appearance on the first day of intranasal dosing to dogs. Changes were noted at the ...
A case of bilateral corneal opacity. George Emmanuel Comia, MD, Ruben Lim Bon Siong, MD ... Corneal diameters were 12 mm for both eyes with normal corneal thickness, intact epithelium, and diffuse mid to posterior ... Corneal topography showed symmetrical bow-tie astigmatism of -3.38D for the right eye and -3.00D for the left eye. Pachymetry ... They concluded that since the opacities were present at birth, the pathologic process may have occurred in utero and may have ...
corneal opacities (see WARNINGS: Corneal Opacities), decreased night vision which may persist (see WARNINGS: Decreased Night ... Corneal Opacities. Corneal opacities have occurred in patients receiving isotretinoin capsules for acne and more frequently ... The corneal opacities that have been observed in clinical trial patients treated with isotretinoin capsules have either ...
Inclusion Criteria: Includes concepts that represent a diagnosis of opacity of the cornea, adherent or corneal leukoma, ... The purpose of this value set is to represent concepts of a diagnosis of corneal opacity and other corneal disorders. Data ... Clinical Focus: The purpose of this value set is to represent concepts of a diagnosis of corneal opacity and other corneal ... Constrained to codes in the Diagnosis: Corneal Opacity and Other Disorders of Cornea value set (2.16.840.1.113883.3.526.3.1419) ...
... corneal opacities, coarsening of facial features, leathery skin, and hypertrichosis. It is one of the inherited osteolyses, or ... Corneal opacities; leathery skin; abnormal collagen in the dermis; and, possibly, contractures are likely manifestations of ... corneal opacities, coarsening of facial features, leathery skin, and hypertrichosis. It is one of the inherited osteolyses, or ... 12] performed corneal biopsy in the younger sibling, whose case is discussed in the report by Winchester et al [2] ; the ...
Ocular signs and symptoms including corneal ulcers, corneal opacities, keratitis, conjunctivitis, eye pain, and photophobia ...
A 53 year old male presents corneal opacity after a mycotic keratitis in left eye. We attempted DALK and a cataract surgery. ... Film 81964: Phacoemulsification, IOL Implantation and Penetrant Keratoplasty in a Patient with Corneal Opacity after Mycotic ... IOL Implantation and Penetrant Keratoplasty in a Patient with Corneal Opacity after Mycotic Keratitis ... Film 82880: Phakic Intraocular Lens in Keratoconus (KCN) Treated Previously with Excimer Corneal Reshaping Followed By Combined ...
corneal opacities). In severe cases affected individuals have a sac-like protrusion of the brain (encephalocele. ) at the front ...
... corneal leukoma, and an undiagnosed scar. Six (42.8%) patients required treatment for their underlying corneal opacity ... To report the birth prevalence and natural history of congenital corneal opacities among a population-based cohort of children ... Fourteen patients were diagnosed with a congenital corneal opacity during the 40-year study period for a birth prevalence of 1 ... congenital onset corneal opacity while residing in Olmsted County, Minnesota, from January 1, 1977, through December 31, 2016, ...
Corneal opacities, enlarged orange tonsils, hepatosplenomegaly, peripheral neuropathy. No to yes. Familial HA ...
CORNEAL OPACITY AND PERMEABILITY MEASUREMENT - Individual and mean corneal opacity measurements and individual and mean corneal ... CORNEAL EPITHELIUM CONDITION - The condition of the cornea immediately after rinsing and at the final opacity measurement is ... A reliable in vitro Bovine Corneal Opacity and Permeability Assay (BCOP), Klimisch score 1, was performed in accordance with ... The mean opacity value of each treatment group was then calculated by averaging the corrected opacity values of each cornea for ...
Development Guidelines for Medical Improvement Not Expected (MINE) or MINE-Equivalent Impairments
... corneal opacity in the right eye; and full blindness in the left eye (Appendix Figure 2). Case-patient 3 was a 45-year-old man ... and corneal opacity in both eyes. Case-patient 4 was a 22-year-old man from Rashakami with a 1-year history of TT, madarosis, ...
corneal opacity, or clouding of the cornea. *cataracts, or clouding of the lens ...
Corneal opacity: Opacitometer. - Corneal permeability: Passage of sodium fluorescein dye measured with the aid of ... OECD 437 (2018) -The Bovine Corneal Opacity and Permeability (BCOP) test was conducted using test item in accordance with OECD ... Following rinsing, the corneas were incubated (vertically) for 120 hours after which, corneal opacity was measured and then the ... OECD Guideline 437 (Bovine Corneal Opacity and Permeability Test Method for Identifying i) Chemicals Inducing Serious Eye ...
Corneal opacity (CO). Corneal opacity blurring part of pupil margin. Trichiasis, right upper lid. ... Trichiasis, pannus, and corneal scarring. This photo demonstrates the stigmata of established trachoma, i.e. trichiasis, pannus ... Severe corneal damage in trachoma patients is due primarily to the constant rubbing of the cornea by errant, bristle-like ... Established trachoma with conjunctivitis, florid pannus, corneal scarring, and trichiasis. Slit-lamp examination of the ...
2014). Vimentin knockdown decreases corneal opacity. Invest. Ophthalmol. Vis. Sci. 55, 4030-4040. doi: 10.1167/iovs.13-13494 ... Corneal fibrosis is the major type of eye fibrosis. Vimentin, a major structural type III intermediate filament, is a required ... component of keratocyte activation and differentiation corneal fibrosis, which often accelerates the process of fibrosis (Das ...
Corneal opacity and oedema. *Post-operative complications (keratoconic). *Glaucoma. *Immature cataract with high eyesight ... Whenever conjunctival or corneal irritation is suspected, the ophthalmologist prescribes the eye swab for microbial culturing. ...
No cases of trachomatous trichiasis or corneal opacity were detected in the sample studied (Table 2). ...
  • Corneal opacification is a term used when the human cornea loses its transparency. (wikipedia.org)
  • The word corneal opacification literally means loss of normal transparency of cornea. (mdwiki.org)
  • prised: demographic details (e.g. name, age, Corneal opacification (traumatic, infec- sex and country of origin), best corrected tious or other) constituted one-fifth of visual visual acuity (VA), basic eye examination, impairment. (who.int)
  • Reis-BĂ¼cklers, formerly known as Granular corneal dystrophy type III or Corneal Dystrophy of Bowman's type I, typically present with normal corneas at birth but develop painful recurrent erosions, opacification, and progressive vision loss within the first decade of life (1). (uiowa.edu)
  • Brown SI, Kuwabara T. Peripheral corneal opacification and skeletal deformities. (medscape.com)
  • Alterations in the spacing of collagen fibrils in a variety of conditions including corneal edema, scars, and macular corneal dystrophy is clinically manifested as corneal opacity. (wikipedia.org)
  • Posterior polymorphous corneal dystrophy (PPMD, PPCD): PPCD, also known as Schlichting dystrophy, is an autosomal dominant disorder of the corneal endothelium and Descemet's membrane. (wikipedia.org)
  • Congenital hereditary stromal dystrophy (CHSD): CHSD is also known as Congenital stromal corneal dystrophy or Congenital stromal dystrophy of the cornea. (wikipedia.org)
  • To report potentially pathogenic mutations in the keratin 3 ( KRT3 ) and keratin 12 ( KRT12 ) genes in two individuals with clinically diagnosed Meesmann corneal dystrophy (MECD). (molvis.org)
  • The hyaline-like material consists of rod-like bodies ultrastructurally, which helps distinguish it from Thiel-Behnke corneal dystrophy (1, 2). (uiowa.edu)
  • Lattice corneal dystrophy (LCD) is the most common of the corneal epithelial-stromal dystrophies. (uiowa.edu)
  • Lattice corneal dystrophy: a source of confusion. (bmj.com)
  • Corneal diameters were 12 mm for both eyes with normal corneal thickness, intact epithelium, and diffuse mid to posterior stromal haze. (paojournal.com)
  • TGFβI is located on chromosome 5q31 and codes for keratoepithelin, a protein secreted by corneal epithelium. (uiowa.edu)
  • The ocular irritation potential of formulations, products, ingredients, and chemicals can be evaluated using in vitro reconstructed human corneal epithelium (RhCE) models, such as the EpiOcularâ„¢ (MatTek Corp.) and SkinEthic HCE (EPISKIN) organotypic 3-D tissue constructs. (iivs.org)
  • Circulating antibodies against corneal epithelium and hookworm in patients with Mooren's ulcer from Sierra Leone. (bmj.com)
  • Following full-thickness corneal transplantation (Penatrating Keratoplasty, PK), rejection may involve any cellular layer of the cornea (epithelium, stroma or endothelium). (college-optometrists.org)
  • HSK is listed by the American Academy of Ophthalmology as a relative contraindication to corneal refractive surgery, although specifics have not been further elucidated. (dovepress.com)
  • Available at: https://www.aao.org/topic-detail/congenital-corneal-opacities-europe. (cvs.com)
  • Birth prevalence and characteristics of congenital corneal opacities. (bvsalud.org)
  • To report the birth prevalence and natural history of congenital corneal opacities among a population -based cohort of children . (bvsalud.org)
  • In this 40-year cohort, congenital corneal opacities were relatively rare and the result of a variety of disorders. (bvsalud.org)
  • The BCOP (Bovine Corneal Opacity and Permeability) assay is an in vitro eye irritation test method developed by Gautheron et al. (iivs.org)
  • Experimental mice, i.e., wild-type, Col5a1 f/f and Kera-Cre/Col5a1 f/f ( Col5a1 ∆st/∆st , collagen V null in the corneal stroma) mice in a C57BL/6J genetic background, were subjected to a lamellar keratectomy, and treated with or without UMSC (10 4 cells/cornea) transplantation via an intrastromal injection or a fibrin plug. (molvis.org)
  • UMSC transplantation was successful in recovering some corneal transparency in injured corneas of wild-type, Col5a1 f/f and Col5a1 ∆st/∆st mice. (molvis.org)
  • Corneal transplantation is one of the common treatment to correct several corneal opacity which involves tissue from human donor. (medgadget.com)
  • However, the treatment fails in some cases, leading to development of keratoprosthesis which is used when corneal transplantation is not an option. (medgadget.com)
  • Increasing incidences of corneal blindness along with patients who have failed human corneal transplantation may create potential growth prospects of the keratoprosthesis market. (medgadget.com)
  • The patient requires a corneal transplantation procedure, preferably DMEK. (crstoday.com)
  • Diseases surgical technique developed since the start of the involving the corneal endothelium can be controlled twentieth century for the realization of corneal with endothelial or penetrating keratoplasties, and transplantation (CT). (bvsalud.org)
  • CT is the most common type those diseases that involve both the endothelium and of tissue transplantation made around the world, the corneal stroma generally require PK when there is substitution of all corneal layers (the (REINHART, 2011). (bvsalud.org)
  • A 53 year old male presents corneal opacity after a mycotic keratitis in left eye. (ascrs.org)
  • Four patients had congenital glaucoma , 4 had limbal dermoids , 2 had sclerocornea, and 1 patient each had Descemet's tear from birth trauma , herpes simplex virus type 1 keratitis , corneal leukoma , and an undiagnosed scar . (bvsalud.org)
  • The incidence of herpes simplex keratitis (HSK) in patients following corneal refractive surgery is higher than in the general population, and several case reports of ocular morbidity in HSK infection following corneal refractive surgery have been published. (dovepress.com)
  • The incidence of graft rejection depends on the presence of risk characteristics, e.g. corneal neovascularization. (college-optometrists.org)
  • Rarely, corneal neovascularization regresses completely without treatment, and corneal transparency is restored. (msdmanuals.com)
  • PPMD patients with bilateral, corneal opacities that can affect vision, descemet's membrane endothelial keratoplasty or penetrating keratoplasty are the treatments of choice to improve vision and to avoid amblyopia. (wikipedia.org)
  • With the development of new surgical techniques, instrumentation and pharmacological advances, corneal transplant procedures can undergo changes directly in the clinical profile of patients with the indication for penetrating keratoplasty technique. (bvsalud.org)
  • The 2015 International Committee for Classification of Corneal Dystrophies (IC3D) classification system has divided corneal dystrophies into 4 categories: epithelial and subepithelial dystrophies, epithelial-stromal dystrophies, stromal dystrophies, and endothelial dystrophies. (uiowa.edu)
  • This case presents a few challenges, including repositioning or replacing the IOL and addressing corneal endothelial decompensation and iris damage. (crstoday.com)
  • One of the major complication of adherent leucoma is Secondary glaucoma Corneoiridic scar: if iris tissue is incarcerated and incorporated within the scar tissue, as occurs in healing of a large sloughed corneal ulcer, it is called a corneoiridic scar. (wikipedia.org)
  • The appearance of the cornea is similar to that in congenital glaucoma but without increased corneal diameter and elevated intraocular pressure. (wikipedia.org)
  • Six (42.8%) patients required treatment for their underlying corneal opacity including the four patients with congenital glaucoma . (bvsalud.org)
  • The commonest causes of bilat- nessisthoughttobeduetochildhood Eyeexaminationincludesslit-lamp, eralblindnesswerecataract(20.0%), blindness[ 2 ].Indevelopingcountries, fundoscopy,retinoscopyandtonom- glaucoma(17.8%),retinaldisorders thecausesofchildhoodblindnesshave etrywhenneeded.Afterestablishing (13.3%) and corneal nontraumatic notbeenwidelystudied.Toplaneffec- thediagnosis,medicinesorglassesare opacities(13.3%)(Table2).Foruni- tiveinterventionandpreventionpro- prescribedasappropriate. (who.int)
  • The term corneal opacity is used particularly for the loss of transparency of cornea due to scarring. (wikipedia.org)
  • In vivo Heidelberg retinal tomograph (HRT II) confocal microscopy, second harmonic generated (SHG) confocal microscopy, histology, and immunofluorescence microscopy were used to assess the corneal transparency of the regenerated corneas. (molvis.org)
  • The production of collagen V by transplanted UMSCs may account for the regeneration of corneal transparency, as exemplified by better collagen fiber organization, as revealed with SHG signals. (molvis.org)
  • Cornea can loss its transparency due to various reasons and it majorly occurs due to some disorders of eye that eventually leads to corneal opacity. (krishnaeyecentre.com)
  • I have found that, in some cases, once the anatomy has been restored, corneal transparency returns, and DMEK is no longer necessary. (crstoday.com)
  • Severe corneal damage in trachoma patients is due primarily to the constant rubbing of the cornea by errant, bristle-like lashes. (uiowa.edu)
  • In January 1992, FDA approved Boston KPro for patients suffering with severe corneal opacity. (medgadget.com)
  • 3 While many recover without permanent visual impairment, 15% will develop severe complications such as persistent pain, dry eye, corneal scarring, and vision loss. (dovepress.com)
  • A number of different presentations of leucomatous corneal opacity exist: Adherent leucoma: results when healing occurs after perforation of cornea with incarceration of iris. (wikipedia.org)
  • In this bilateral Snowflake, whitish opacities appear throughout the cornea. (wikipedia.org)
  • Corneal opacity is a disorder of the cornea that occur due to scarring or clouding of the normally clear and transparent cornea. (krishnaeyecentre.com)
  • Corneal clouding stops the light from passing through the cornea to the retina and therefore results in decreased vision. (krishnaeyecentre.com)
  • Corneal opacity is scarring of the cornea. (cvs.com)
  • Corneal epithelial-stromal and stromal dystrophies are a group of inherited disorders of the cornea that are caused by progressive accumulation of deposits within the layers of the cornea. (uiowa.edu)
  • The test method evaluates the cytotoxicity induced by a series of test chemical dilutions in a monolayer of rabbit corneal fibroblasts (Statens Seruminstitut Rabbit Cornea - SIRC) after a single five-minute exposure. (iivs.org)
  • The term corneal blindness is commonly used to describe blindness due to corneal opacity. (wikipedia.org)
  • Signs and symptoms include the following: Loss of vision or blindness (when dense opacity covers the pupillary area) Blurred vision (due to astigmatic effect and light scattering) Glare Congenital corneal opacity that affecting vision will cause amblyopia. (wikipedia.org)
  • When left untreated infection can cause irreversible corneal opacities and blindness. (kit.nl)
  • To avoid blindness and restore the damaged eye corneal surgery is the most adopted choice. (medgadget.com)
  • Around 10 million people in the world suffering from corneal blindness. (medgadget.com)
  • Therefore, rising incidences of corneal blindness are the primary factor driving the growth of the global keratoprosthesis market. (medgadget.com)
  • Depending on the density, corneal opacity is graded as nebular, macular and leucomatous. (wikipedia.org)
  • Macular corneal opacity is a semidense opacity produced when scarring involves about half the corneal stroma. (wikipedia.org)
  • Ocular trauma Corneal ulceration Xerophthalmia, caused by Vitamin A deficiency Trachoma Onchocerciasis Mucous membrane pemphigoid: Ocular form of mucous membrane pemphigoid may cause corneal opacity and loss of vision. (wikipedia.org)
  • This photo demonstrates the stigmata of established trachoma, i.e. trichiasis, pannus, and corneal scarring. (uiowa.edu)
  • The risk of corneal opacity rose with increasing exposure to total amines (OR=1.15, 95% CI= 1.02, 1.30). (cdc.gov)
  • Nebular corneal opacity is a faint opacity which results due to superficial scars involving Bowman's layer and superficial stroma. (wikipedia.org)
  • Leucomatous corneal opacity is a dense white opacity which results due to scarring of more than half of the stroma. (wikipedia.org)
  • Maintenance of a transparent corneal stroma is imperative for proper vision. (molvis.org)
  • The corneal stroma is composed of primarily collagen fibrils, small leucine-rich proteoglycans (SLRPs), as well as sparsely distributed cells called keratocytes. (molvis.org)
  • Being a small protein roughly the size of albumin, it has the capability to diffuse through the corneal stroma. (uiowa.edu)
  • Irregular, grey-white, geographic-like opacities are located in the Bowman layer and anterior stroma. (uiowa.edu)
  • In more advanced stages of the disease, the opacities can extend to the limbus and deeper stroma (2). (uiowa.edu)
  • It is characterized by lattice lines which are linear, radially oriented, branching refractile opacities described as 'glass like' located in the anterior stroma (See Figure 2A and 2B). (uiowa.edu)
  • It is typically an autosomal dominant, bilateral disease that typically presents toward the end of the first decade of life with symptoms of recurrent corneal erosions and decreased vision. (uiowa.edu)
  • En dĂ©cembre 2019, la population de Wuhan, une grande ville chinoise de 11 millions d'habitants, est atteinte par une pneumonie virale extrĂªmement contagieuse due au coronavirus SARSCoV-2. (bvsalud.org)
  • Binocularblindnesswasdefinedasa cataract(34.8%),followedbytrauma- ofblindnessandthemagnitudeofthe correctedvisualacuityof3/60orbelow relatedcomplications(19.1%),corneal problemiscrucial. (who.int)
  • Corneal opacity is caused by infection, injury, or swelling of the eye. (cvs.com)
  • The keratoprosthesis market is expected to grow exponentially over the forecast period due to increasing incidence of corneal infection. (medgadget.com)
  • A variety of biologic materials are being considered for improving the prosthetic corneal implants. (medgadget.com)
  • KPro) is the most widely used prosthetic corneal transplant in the United States and the world [ 1 ]. (hindawi.com)
  • Lymphoid follicles on the tarsal plate or along the corneal limbus, linear conjunctival scarring, and corneal pannus are considered diagnostic in the appropriate clinical setting. (msdmanuals.com)
  • The purpose of this value set is to represent concepts of a diagnosis of corneal opacity and other corneal disorders. (healthit.gov)
  • This review summarizes the current literature regarding reactivation of HSK following corneal refractive surgery and provides a guideline for considering corneal refractive surgery in a patient with a previous history of HSK. (dovepress.com)
  • Based on the current literature, we recommend that corneal refractive surgery is appropriate for patients with a history of HSK without multiple recurrences who have had no evidence of disease for at least one year. (dovepress.com)
  • Other occasional abnormalities are relatively large big toe and corneal clouding. (paojournal.com)
  • Other features include hyperpigmented macules on the trunk, corneal opacities, other hematological abnormalities. (lu.se)
  • Case-patient 3 was a 45-year-old man from Kuyuwiniña with a 5-year history of TT, madarosis, blepharitis, conjunctivitis, and corneal opacity in both eyes. (cdc.gov)
  • The prevalence of increased corneal thickness in either eye increased with higher levels of exposure to total amines, as did both the mean and median changes in thickness. (cdc.gov)
  • Median corneal thickness increased with increasing grades of corneal opacity. (cdc.gov)
  • Corneal transplant rejection is the most common cause of transplant failure in the post-operative period. (college-optometrists.org)
  • In 'high-risk' corneal transplant recipients up to 70% fail within 10 years despite local or systemic immunosuppressive therapy. (college-optometrists.org)
  • A nebular corneal opacity allows the details of the iris to be seen through the opacity. (wikipedia.org)
  • Kerectasia: In this condition, corneal curvature is increased at the site of opacity (bulge due to weak scar). (wikipedia.org)
  • Corneoiridic scar: If iris tissue is incarcerated and incorporated within the scar tissue, as occurs in healing of a large sloughed corneal ulcer, it is called a corneoiridic scar. (mdwiki.org)
  • Examination shows inferior corneal edema and a dislocated three-piece IOL, with optic capture inferiorly and the inferior haptic in the anterior chamber (Figure). (crstoday.com)
  • Corneal edema inferiorly and optic capture of a three-piece IOL, the inferior haptic of which is in the anterior chamber. (crstoday.com)
  • Media opacity from focal corneal edema must also be considered. (crstoday.com)
  • I would prefer a superior approach to avoid constructing the wound in the area of corneal edema. (crstoday.com)
  • The second proband demonstrated bilateral, diffusely distributed epithelial opacities that appeared gray-white on direct illumination and translucent on retroillumination. (molvis.org)
  • Riboflavin is found essential for iron absorption, gastrointestinal development, neurogenesis, corneal vascularization and corneal opacity. (sigmaaldrich.com)
  • Pediatric corneal opacities may be congenital or acquired. (wikipedia.org)
  • Fourteen patients were diagnosed with a congenital corneal opacity during the 40-year study period for a birth prevalence of 1 in 5188 live births . (bvsalud.org)
  • Patients with refractive er- that of corneal opacities in our study group. (who.int)
  • The keratoprosthesis is intended to replace the damaged corneal tissue and restore vision of the patients with bilateral corneal disease. (medgadget.com)
  • Dès le dĂ©but de la pandĂ©mie, l'Ă©tablissement hospitalier et universitaire d'Oran (EHUO), centre de soins de première ligne, d'une capacitĂ© 780 lits desservant environ 2 millions d'habitants s'est complètement rĂ©organisĂ©, en amĂ©nageant principalement des circuits pour le tri des patients « suspects Covid 19 ¼. (bvsalud.org)
  • Ocular form of mucous membrane pemphigoid may cause corneal opacity and loss of vision. (mdwiki.org)
  • The Ocular Irritection Assay is an in chemico eye irritation assay that detects, ranks, and predicts the corneal irritation potential of a test material. (iivs.org)
  • 1992), which uses living bovine corneal tissue, obtained as a by-product from abattoirs, to evaluate the potential ocular irritancy of a test article. (iivs.org)
  • Corneal opacities--a diagnostic feature of the trisomy 8 mosaic syndrome. (bmj.com)
  • Thirteen of these eyes had hypotony and/or retinal detachment in addition to corneal pathology and thus received KPro + PPV + SOI. (hindawi.com)
  • The addition of PPV and SOI to the KPro implantation in the eyes with corneal pathology, as well as hypotony and/or retinal detachment, is a safe and effective procedure for visual rehabilitation. (hindawi.com)
  • Congenital opacities may occur as developmental anomalies or following birth trauma. (wikipedia.org)
  • As corneal keratins naturally occur as obligate K3/K12 heterodimers, gene mutations altering the encoded protein of either KRT3 or KRT12 are expected to negatively impact the K3/K12 heterodimer complex. (molvis.org)
  • Corneal topography showed symmetrical bow-tie astigmatism of -3.38D for the right eye and -3.00D for the left eye. (paojournal.com)