Glossary
Age-related macular degeneration (AMD, ARMD)
A group of conditions that include deterioration of the macula, resulting in loss of sharp central vision. Two general types: dry, which is more common, and wet, in which abnormal new blood vessels grow under the retina and leak fluid and blood (neovascularization), further disturbing macular function. Most common cause of decreased vision after the age of 60.
Amsler grid
Test card; grid (black lines on white background or white lines on black background) used for detecting central visual field distortions, or defects, such as in macular degeneration.
Applanation
An instrument measures intraocular pressure by determination of the force necessary to flatten a corneal surface of constant size.
B-scan
Type of ultrasound; provides a cross-section view of tissues that cannot be seen directly. High frequency waves are reflected by eye tissues and orbital structures and converted into electrical pulses, which are displayed on a printout.
Diabetic Retinopathy
Spectrum of retinal changes accompanying long-standing diabetes mellitus. Early stage is background retinopathy. May advance to proliferative retinopathy, which includes the growth of abnormal new blood vessels (neovascularization) and fibrous tissue
Drusen
Tiny, white hyalin deposits on Bruch's membrane (of the retinal pigment epithelium). Common after age 60; sometimes an early sign of macular degeneration
Floaters
Particles that float in the vitreous and cast shadows on the retina; seen as spots, cobwebs, spiders, etc. Occurs normally with aging or with vitreous detachment, retinal tears, or inflammation.
Fluorescein Angiography
Technique used for visualizing and recording location and size of blood vessels and any eye problems affecting them; fluorescein dye is injected into an arm vein, then rapid, sequential photographs are take of the eye as the dye circulates.
Fovea
Central pit in the macula that produces sharpest vision. Contains a high concentration of cones and no retinal blood vessels.
Fundus
Interior posterior surface of the eyeball; includes retina, optic disk, macula, posterior pole. Can be seen with an ophthalmoscope.
Laser (Light Amplification by Stimulated Emission of Radiation)
High energy light source that uses light emitted by the natural vibrations of atoms (of a gas or solid material) to cut, burn or dissolve tissues for various clinical purposes; in the retina, to treat diabetic retinopathy and macular degeneration, to destroy leaking and new blood vessels (neovascularization); on the iris or trabecular meshwork, to decrease pressure in glaucoma; after extracapsular cataract extraction, to open the posterior lens capsule.
Macula
Small central area of the retina surrounding the fovea; area of acute central vision.
Macular Edema
Swelling of the macula from leaking fluid; may cause blurred vision
Neovascularization
Abnormal formation of new blood vessels, usually in or under the retina, or on the iris surface. May develop in diabetic retinopathy, blockage of the central retinal vein, or macular degeneration.
Peripheral Vision
Side vision; vision elicited by stimuli falling on retinal areas distant from the macula.
Retina
Light-sensitive nerve tissue in the eye that converts images from the eye's optical system into electrical impulses that are sent along the optic nerve to the brain.
Retinal Detachment
Separation of the retina from the underlying pigment epithelium. Disrupts visual cell structure and thus markedly disturbs vision. Almost always caused by a retinal tear; often requires immediate surgical repair.
Sclera
Opaque, fibrous, protective outer layer of the eye (white of the eye) that is directly continuous with the cornea in front and with the sheath covering optic nerve behind.
Vitrectomy
A surgical procedure where blood is removed from the center of the eye.
Vitreous (Vitreous Humor)
Transparent, colorless, gelatinous mass that fills the rear two-thirds of the eyeball, between the lens and the retina.
Vitreous Detachment
Spearation of vitreous gel from retinal surface. Usually innocuous, but can cause retinal tears, which may lead to retinal detachment. Frequently occurs with aging as the vitreous liquifies, or in some disease states, e.g. diabetes and high myopia.
Source - 2007 Eye Care America - Foundation of the American Academy of Ophthalmology
