- FDA): 3 times as much vitamin A, 8 times as much vitamin C, 13 times as much vitamin E and 5 times as much zinc.
* * *macular degeneration n progressive deterioration of the macula lutea resulting in a gradual loss of the central part of the field of vision esp age-related macular degeneration
* * *a group of conditions affecting the macula lutea of the eye, resulting in a reduction or loss of central vision. Age-related macular degeneration (AMD, ARMD) is the most common cause of blindness in the elderly. Two types are commonly recognized. Atrophic (or dry) AMD results from chronic choroidal ischaemia: small blood vessels of the choroid, which lies beneath the retina, become constricted, reducing the blood supply to the macula. This gives rise to degenerative changes in the retinal pigment epithelium (RPE; see retina), clinically recognized by macular pigmentation and the deposition of drusen. Wet AMD is associated with the growth of abnormal new blood vessels under the retina, derived from the choroid (see neovascularization). These can leak fluid and blood into the RPE, which further reduces macular function. Laser surgery (see photocoagulation) can halt the degenerative process.
* * *degenerative changes in the macula lutea. Age-related macular degeneration (q.v.) is the most common cause of blindness in persons over age 65. Less common types that are congenital are Best disease and Stargardt disease (see under disease).
Medical dictionary. 2011.
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Macular degeneration — Classification and external resources Picture of the fundus showing intermediate age related macular degeneration. ICD 10 … Wikipedia
macular degeneration — n. an eye disorder in which the macula lutea gradually deteriorates, resulting in blurred vision, blind spots, etc … English World dictionary
macular degeneration — noun eye disease caused by degeneration of the cells of the macula lutea and results in blurred vision; can cause blindness • Hypernyms: ↑eye disease, ↑degeneration, ↑devolution • Hyponyms: ↑age related macular degeneration, ↑AMD * * * noun … Useful english dictionary
macular degeneration — a group of conditions affecting the macula lutea of the eye, resulting in a reduction or loss of central vision. Age related macular degeneration (AMD, ARMD) is the most common cause of blindness in the elderly. Two types are commonly recognized … The new mediacal dictionary
macular degeneration — Ophthalm. degeneration of the central portion of the retina, resulting in a loss of sharp vision. * * * Degeneration of the macula (central part of the retina), with corresponding visual field defect. It is the leading cause of blindness in old… … Universalium
macular degeneration — mac′ular degenera′tion n. oph degeneration of the macula in the center of the retina, resulting in a loss of central vision but not affecting peripheral vision … From formal English to slang
macular degeneration — noun Date: 1918 a gradual loss of the central part of the field of vision usually affecting both eyes that occurs especially in the elderly and that in a slowly progressing form is marked especially by accumulation of yellow deposits in and… … New Collegiate Dictionary
macular degeneration — noun A disease of the retina of the eye resulting in loss of central vision … Wiktionary
macular degeneration — /ˌmækjələ dədʒɛnəˈreɪʃən/ (say .makyuhluh duhjenuh rayshuhn) noun Ophthalmology a degenerative disease of the macula (def. 2), causing a progressive loss of central vision … Australian English dictionary
Age-related macular degeneration — A disease with it onset usually after age 60 that progressively destroys the macula, the central portion of the retina, impairing central vision. Age related macular degeneration (AME) rarely causes blindness because only the center of vision is… … Medical dictionary