The space in the eye, filled with aqueous humor, bounded anteriorly by the cornea and a small portion of the sclera and posteriorly by a small portion of the ciliary body, the iris, and that part of the crystalline lens which presents through the pupil. (Cline et al., Dictionary of Visual Science, 4th ed, p109)
The most anterior portion of the uveal layer, separating the anterior chamber from the posterior. It consists of two layers - the stroma and the pigmented epithelium. Color of the iris depends on the amount of melanin in the stroma on reflection from the pigmented epithelium.
The clear, watery fluid which fills the anterior and posterior chambers of the eye. It has a refractive index lower than the crystalline lens, which it surrounds, and is involved in the metabolism of the cornea and the crystalline lens. (Cline et al., Dictionary of Visual Science, 4th ed, p319)
The front third of the eyeball that includes the structures between the front surface of the cornea and the front of the VITREOUS BODY.
Examination of the angle of the anterior chamber of the eye with a specialized optical instrument (gonioscope) or a contact prism lens.
A form of glaucoma in which the intraocular pressure increases because the angle of the anterior chamber is blocked and the aqueous humor cannot drain from the anterior chamber.
The pressure of the fluids in the eye.
A porelike structure surrounding the entire circumference of the anterior chamber through which aqueous humor circulates to the canal of Schlemm.
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)
The removal of a cataractous CRYSTALLINE LENS from the eye.
The organ of sight constituting a pair of globular organs made up of a three-layered roughly spherical structure specialized for receiving and responding to light.
Diseases, dysfunctions, or disorders of or located in the iris.
A ring of tissue extending from the scleral spur to the ora serrata of the RETINA. It consists of the uveal portion and the epithelial portion. The ciliary muscle is in the uveal portion and the ciliary processes are in the epithelial portion.
The white, opaque, fibrous, outer tunic of the eyeball, covering it entirely excepting the segment covered anteriorly by the cornea. It is essentially avascular but contains apertures for vessels, lymphatics, and nerves. It receives the tendons of insertion of the extraocular muscles and at the corneoscleral junction contains the canal of Schlemm. (From Cline et al., Dictionary of Visual Science, 4th ed)
The use of statistical and mathematical methods to analyze biological observations and phenomena.
Insertion of an artificial lens to replace the natural CRYSTALLINE LENS after CATARACT EXTRACTION or to supplement the natural lens which is left in place.
Inflammation of the anterior uvea comprising the iris, angle structures, and the ciliary body. Manifestations of this disorder include ciliary injection, exudation into the anterior chamber, iris changes, and adhesions between the iris and lens (posterior synechiae). Intraocular pressure may be increased or reduced.
Bleeding in the anterior chamber of the eye.
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.
Artificial implanted lenses.
An ocular disease, occurring in many forms, having as its primary characteristics an unstable or a sustained increase in the intraocular pressure which the eye cannot withstand without damage to its structure or impairment of its function. The consequences of the increased pressure may be manifested in a variety of symptoms, depending upon type and severity, such as excavation of the optic disk, hardness of the eyeball, corneal anesthesia, reduced visual acuity, seeing of colored halos around lights, disturbed dark adaptation, visual field defects, and headaches. (Dictionary of Visual Science, 4th ed)
A procedure for removal of the crystalline lens in cataract surgery in which an anterior capsulectomy is performed by means of a needle inserted through a small incision at the temporal limbus, allowing the lens contents to fall through the dilated pupil into the anterior chamber where they are broken up by the use of ultrasound and aspirated out of the eye through the incision. (Cline, et al., Dictionary of Visual Science, 4th ed & In Focus 1993;1(1):1)
An excessive amount of fluid in the cornea due to damage of the epithelium or endothelium causing decreased visual acuity.
Measurement of light given off by fluorescein in order to assess the integrity of various ocular barriers. The method is used to investigate the blood-aqueous barrier, blood-retinal barrier, aqueous flow measurements, corneal endothelial permeability, and tear flow dynamics.
Suppurative inflammation of the tissues of the internal structures of the eye frequently associated with an infection.
Single layer of large flattened cells covering the surface of the cornea.
Diseases affecting the eye.
Tumors or cancer of the EYE.
The transparent, semigelatinous substance that fills the cavity behind the CRYSTALLINE LENS of the EYE and in front of the RETINA. It is contained in a thin hyaloid membrane and forms about four fifths of the optic globe.
The selectively permeable barrier, in the EYE, formed by the nonpigmented layer of the EPITHELIUM of the CILIARY BODY, and the ENDOTHELIUM of the BLOOD VESSELS of the IRIS. TIGHT JUNCTIONS joining adjacent cells keep the barrier between cells continuous.
Surgical removal of a section of the iris.
Incomplete rupture of the zonule with the displaced lens remaining behind the pupil. In dislocation, or complete rupture, the lens is displaced forward into the anterior chamber or backward into the vitreous body. When congenital, this condition is known as ECTOPIA LENTIS.
A transparent, biconvex structure of the EYE, enclosed in a capsule and situated behind the IRIS and in front of the vitreous humor (VITREOUS BODY). It is slightly overlapped at its margin by the ciliary processes. Adaptation by the CILIARY BODY is crucial for OCULAR ACCOMMODATION.
Refraction of LIGHT effected by the media of the EYE.
The pigmented vascular coat of the eyeball, consisting of the CHOROID; CILIARY BODY; and IRIS, which are continuous with each other. (Cline et al., Dictionary of Visual Science, 4th ed)
Inflammation of the iris characterized by circumcorneal injection, aqueous flare, keratotic precipitates, and constricted and sluggish pupil along with discoloration of the iris.
Introduction of substances into the body using a needle and syringe.
A layer of the cornea. It is the basal lamina of the CORNEAL ENDOTHELIUM (from which it is secreted) separating it from the CORNEAL STROMA. It is a homogeneous structure composed of fine collagenous filaments, and slowly increases in thickness with age.
A procedure in which fluid is withdrawn from a body cavity or organ via a trocar and cannula, needle, or other hollow instrument.
The distance between the anterior and posterior poles of the eye, measured either by ULTRASONOGRAPHY or by partial coherence interferometry.
Partial or total replacement of the CORNEA from one human or animal to another.
Mild to severe infections of the eye and its adjacent structures (adnexa) by adult or larval protozoan or metazoan parasites.
Deviations from the average or standard indices of refraction of the eye through its dioptric or refractive apparatus.
Measurement of ocular tension (INTRAOCULAR PRESSURE) with a tonometer. (Cline, et al., Dictionary of Visual Science, 4th ed)
The surgical removal of the eyeball leaving the eye muscles and remaining orbital contents intact.
Sterile solutions that are intended for instillation into the eye. It does not include solutions for cleaning eyeglasses or CONTACT LENS SOLUTIONS.
An imaging method using LASERS that is used for mapping subsurface structure. When a reflective site in the sample is at the same optical path length (coherence) as the reference mirror, the detector observes interference fringes.
Substances that display the physical properties of ELASTICITY and VISCOSITY. The dual-nature of these substances causes them to resist applied forces in a time-dependent manner.
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.
Inflammation of part or all of the uvea, the middle (vascular) tunic of the eye, and commonly involving the other tunics (sclera and cornea, and the retina). (Dorland, 27th ed)
Diseases of the uvea.
A refractive error in which rays of light entering the EYE parallel to the optic axis are brought to a focus in front of the RETINA when accommodation (ACCOMMODATION, OCULAR) is relaxed. This results from an overly curved CORNEA or from the eyeball being too long from front to back. It is also called nearsightedness.
Any surgical procedure for treatment of glaucoma by means of puncture or reshaping of the trabecular meshwork. It includes goniotomy, trabeculectomy, and laser perforation.
Diseases of the cornea.
Devices used in a technique by which cells or tissues are grown in vitro or, by implantation, in vivo within chambers permeable to diffusion of solutes across the chamber walls. The chambers are used for studies of drug effects, osmotic responses, cytogenic and immunologic phenomena, metabolism, etc., and include tissue cages.
The aperture in the iris through which light passes.
Infections in the inner or external eye caused by microorganisms belonging to several families of bacteria. Some of the more common genera found are Haemophilus, Neisseria, Staphylococcus, Streptococcus, and Chlamydia.
Abnormally low intraocular pressure often related to chronic inflammation (uveitis).
The use of photothermal effects of LASERS to coagulate, incise, vaporize, resect, dissect, or resurface tissue.
A refractive error in which rays of light entering the eye parallel to the optic axis are brought to a focus behind the retina, as a result of the eyeball being too short from front to back. It is also called farsightedness because the near point is more distant than it is in emmetropia with an equal amplitude of accommodation. (Dorland, 27th ed)
Methods and procedures for the diagnosis of diseases of the eye or of vision disorders.
The thin noncellular outer covering of the CRYSTALLINE LENS composed mainly of COLLAGEN TYPE IV and GLYCOSAMINOGLYCANS. It is secreted by the embryonic anterior and posterior epithelium. The embryonic posterior epithelium later disappears.
Presence of an intraocular lens after cataract extraction.
An increased reactivity to specific antigens mediated not by antibodies but by cells.
Disorder occurring in the central or peripheral area of the cornea. The usual degree of transparency becomes relatively opaque.
Agents that dilate the pupil. They may be either sympathomimetics or parasympatholytics.
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)
Inflammation of the RETINA. It is rarely limited to the retina, but is commonly associated with diseases of the choroid (CHORIORETINITIS) and of the OPTIC DISK (neuroretinitis).
Congenital absence of or defects in structures of the eye; may also be hereditary.
A form of secondary glaucoma which develops as a consequence of another ocular disease and is attributed to the forming of new vessels in the angle of the anterior chamber.
Measurement of distances or movements by means of the phenomena caused by the interference of two rays of light (optical interferometry) or of sound (acoustic interferometry).
The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.
A condition in which the intraocular pressure is elevated above normal and which may lead to glaucoma.
Processes and properties of the EYE as a whole or of any of its parts.
The measurement of curvature and shape of the anterior surface of the cornea using techniques such as keratometry, keratoscopy, photokeratoscopy, profile photography, computer-assisted image processing and videokeratography. This measurement is often applied in the fitting of contact lenses and in diagnosing corneal diseases or corneal changes including keratoconus, which occur after keratotomy and keratoplasty.
Damage or trauma inflicted to the eye by external means. The concept includes both surface injuries and intraocular injuries.
Infections of the eye caused by minute intracellular agents. These infections may lead to severe inflammation in various parts of the eye - conjunctiva, iris, eyelids, etc. Several viruses have been identified as the causative agents. Among these are Herpesvirus, Adenovirus, Poxvirus, and Myxovirus.
Surgical formation of an external opening in the sclera, primarily in the treatment of glaucoma.
Glaucoma in which the angle of the anterior chamber is open and the trabecular meshwork does not encroach on the base of the iris.
Removal of the whole or part of the vitreous body in treating endophthalmitis, diabetic retinopathy, retinal detachment, intraocular foreign bodies, and some types of glaucoma.
Loss of CORNEAL ENDOTHELIUM usually following intraocular surgery (e.g., cataract surgery) or due to FUCHS' ENDOTHELIAL DYSTROPHY; ANGLE-CLOSURE GLAUCOMA; IRITIS; or aging.
Intraocular hemorrhage from the vessels of various tissues of the eye.
A species of the genus MACACA which typically lives near the coast in tidal creeks and mangrove swamps primarily on the islands of the Malay peninsula.
A slowly hydrolyzed muscarinic agonist with no nicotinic effects. Pilocarpine is used as a miotic and in the treatment of glaucoma.
One of the MUSCARINIC ANTAGONISTS with pharmacologic action similar to ATROPINE and used mainly as an ophthalmic parasympatholytic or mydriatic.
Surgery performed on the eye or any of its parts.
An alpha-adrenergic blocking agent that is used in Raynaud's disease. It is also used locally in the eye to reverse the mydriasis caused by phenylephrine and other sympathomimetic agents. (From Martindale, The Extra Pharmacopoeia, 30th ed, p1312)
Experimental devices used in inhalation studies in which a person or animal is either partially or completely immersed in a chemically controlled atmosphere.
Method of making images on a sensitized surface by exposure to light or other radiant energy.
Transmission of gene defects or chromosomal aberrations/abnormalities which are expressed in extreme variation in the structure or function of the eye. These may be evident at birth, but may be manifested later with progression of the disorder.
Acute or chronic inflammation of the iris and ciliary body characterized by exudates into the anterior chamber, discoloration of the iris, and constricted, sluggish pupil. Symptoms include radiating pain, photophobia, lacrimation, and interference with vision.
The making of a continuous circular tear in the anterior capsule during cataract surgery in order to allow expression or phacoemulsification of the nucleus of the lens. (Dorland, 28th ed)
Agents causing contraction of the pupil of the eye. Some sources use the term miotics only for the parasympathomimetics but any drug used to induce miosis is included here.
The back two-thirds of the eye that includes the anterior hyaloid membrane and all of the optical structures behind it: the VITREOUS HUMOR; RETINA; CHOROID; and OPTIC NERVE.
Absence of the crystalline lens resulting from cataract extraction.
A phthalic indicator dye that appears yellow-green in normal tear film and bright green in a more alkaline medium such as the aqueous humor.
A parasympatholytic anticholinergic used solely to obtain mydriasis or cycloplegia.
The core of the crystalline lens, surrounded by the cortex.
Inanimate objects that become enclosed in the eye.
Deeply perforating or puncturing type intraocular injuries.
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.
Partial or total replacement of all layers of a central portion of the cornea.
Organic siloxanes which are polymerized to the oily stage. The oils have low surface tension and density less than 1. They are used in industrial applications and in the treatment of retinal detachment, complicated by proliferative vitreoretinopathy.
A family of spiro(isobenzofuran-1(3H),9'-(9H)xanthen)-3-one derivatives. These are used as dyes, as indicators for various metals, and as fluorescent labels in immunoassays.
Tumors of the iris characterized by increased pigmentation of melanocytes. Iris nevi are composed of proliferated melanocytes and are associated with neurofibromatosis and malignant melanoma of the choroid and ciliary body. Malignant melanoma of the iris often originates from preexisting nevi.
Congenital or developmental anomaly in which the eyeballs are abnormally small.
The mucous membrane that covers the posterior surface of the eyelids and the anterior pericorneal surface of the eyeball.
Inflammation of the cornea.
The application of drug preparations to the surfaces of the body, especially the skin (ADMINISTRATION, CUTANEOUS) or mucous membranes. This method of treatment is used to avoid systemic side effects when high doses are required at a localized area or as an alternative systemic administration route, to avoid hepatic processing for example.
A surgical procedure used in treatment of glaucoma in which an opening is created through which aqueous fluid may pass from the anterior chamber into a sac created beneath the conjunctiva, thus lowering the pressure within the eye. (Hoffman, Pocket Glossary of Ophthalmologic Terminology, 1989)
The protrusion of an organ or part of an organ into a natural or artificial orifice.
The ten-layered nervous tissue membrane of the eye. It is continuous with the OPTIC NERVE and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the CHOROID and the inner surface with the VITREOUS BODY. The outer-most layer is pigmented, whereas the inner nine layers are transparent.
The administration of substances into the eye with a hypodermic syringe.
The lamellated connective tissue constituting the thickest layer of the cornea between the Bowman and Descemet membranes.
The dioptric adjustment of the EYE (to attain maximal sharpness of retinal imagery for an object of regard) referring to the ability, to the mechanism, or to the process. Ocular accommodation is the effecting of refractive changes by changes in the shape of the CRYSTALLINE LENS. Loosely, it refers to ocular adjustments for VISION, OCULAR at various distances. (Cline et al., Dictionary of Visual Science, 4th ed)
The theory that human CHARACTER and BEHAVIOR are shaped by the GENES that comprise the individual's GENOTYPE rather than by CULTURE; ENVIRONMENT; and individual choice.
Pathologic processes that affect patients after a surgical procedure. They may or may not be related to the disease for which the surgery was done, and they may or may not be direct results of the surgery.
Measuring and weighing systems and processes.
A surgical specialty concerned with the structure and function of the eye and the medical and surgical treatment of its defects and diseases.
A filarial parasite primarily affecting dogs and cats, but causing an emerging zoonosis in humans involving subcutaneous lesions. It is transmitted by MOSQUITOES.
Lenses, generally made of plastic or silicone, that are implanted into the eye in front of the natural EYE LENS, by the IRIS, to improve VISION, OCULAR. These intraocular lenses are used to supplement the natural lens instead of replacing it.
Mild to fulminant necrotizing vaso-occlusive retinitis associated with a high incidence of retinal detachment and poor vision outcome.
Pupillary constriction. This may result from congenital absence of the dilatator pupillary muscle, defective sympathetic innervation, or irritation of the CONJUNCTIVA or CORNEA.
The washing of a body cavity or surface by flowing water or solution for therapy or diagnosis.
A form of herpetic keratitis characterized by the formation of small vesicles which break down and coalesce to form recurring dendritic ulcers, characteristically irregular, linear, branching, and ending in knoblike extremities. (Dictionary of Visual Science, 3d ed)
Devices, usually incorporating unidirectional valves, which are surgically inserted in the sclera to maintain normal intraocular pressure.
Lasers which use a solid, as opposed to a liquid or gas, as the lasing medium. Common materials used are crystals, such as YAG (YTTRIUM aluminum garnet); alexandrite; and CORUNDUM, doped with a rare earth element such as a NEODYMIUM; ERBIUM; or HOLMIUM. The output is sometimes additionally modified by addition of non-linear optical materials such as potassium titanyl phosphate crystal, which for example is used with neodymium YAG lasers to convert the output light to the visible range.
Application of pharmaceutically active agents on the tissues of the EYE.
A beta-adrenergic antagonist similar in action to PROPRANOLOL. The levo-isomer is the more active. Timolol has been proposed as an antihypertensive, antiarrhythmic, antiangina, and antiglaucoma agent. It is also used in the treatment of MIGRAINE DISORDERS and tremor.
Any fluid-filled closed cavity or sac that is lined by an EPITHELIUM. Cysts can be of normal, abnormal, non-neoplastic, or neoplastic tissues.
Inflammation of the choroid in which the sensory retina becomes edematous and opaque. The inflammatory cells and exudate may burst through the sensory retina to cloud the vitreous body.
Separation of the inner layers of the retina (neural retina) from the pigment epithelium. Retinal detachment occurs more commonly in men than in women, in eyes with degenerative myopia, in aging and in aphakia. It may occur after an uncomplicated cataract extraction, but it is seen more often if vitreous humor has been lost during surgery. (Dorland, 27th ed; Newell, Ophthalmology: Principles and Concepts, 7th ed, p310-12).