Macular degeneration is a major cause of gradual, painless, central vision loss in the elderly.(1) Previously known as "senile macular degeneration," the name has been changed to age-related macular degeneration, (ARMD), due to the unflattering reference to advanced age. The average age at onset of visual loss is about 75 years. After the age of 50 years, the incidence steadily increases; over one-third of people in their ninth decade of life are affected.(2) The actual incidence of the disease depends upon how it is defined. The Framingham Eye Study revealed that ARMD affects about 2% of Americans aged 52-64 years: 11% aged 65-74 years; and 28% aged 75 years and older.(3)
Despite its prevalence there is a lot about macular degeneration that remains unclear. Researchers have implied that certain conditions may contribute to the disorder. Some of these are arteriosclerosis, oxidative damage, photic damage, inflammation, diet, vitamin and rare element deficiencies, and genetics. The genetic factors that are suspected in being involved are hard to quantify due to the fact that parents and siblings may not be alive, and children may be too young to display any symptoms that could be traced leading to the disease. A recent study has suggested that depression may contribute to ARMD as well.(4)
As with most diseases, however, it has been determined that there are some apparent risk factors that are associated. Two of these are hypertension and cigarette smoking. Other suggested risk factors include far-sightedness and the normal risk factors associated with cardiovascular disease. Years ago, scientists thought there was a relationship between light and the development of ARMD. However, more recent studies found no correlation to either visible light nor a light iris color and increased risk. More recently, the role of ocular blood flow in ARMD has been studied to see if there is a relationship between blood flow and the disease itself.(5)
1 Horton JC.
Disorders of the eye. In: Fauci AS, Braunwald E, Isselbacher KJ, et al, eds.
Harrison’s Principles of Internal Medicine, 14th ed. New York: McGraw-Hill;
2 Edwards MG, Bressler NM, Raja SC. Macular disorders-Age-related macular degeneration. In: Yanoff M, Duku JS, Augsbuger JJ, et al, eds. Ophthalmology, 1st ed. London, UK: Mosby International; 1999:8-28.1--8-28.9.
3 Leibowitz HM, Krueger DE, Maunder LR, et al. The Framingham Eye Study Monograph: an ophthalmological and epidemiological study of cataract, glaucoma, diabetic retinopathy, macular degeneration, and visual acuity in a general population of 2631 adults, 1973-1975. Surv Ophthalmol. 1980;24(Suppl):335-610.
4 Rovner BW, Casten RJ, Tasman WS. Effect of Depression on Vision Function in Age-Related Macular Degeneration. Arch Ophthalmol. 2002;120:1041-1044.
5 Friedman E, Krupsky S, Lane AM, et al. Ocular blood flow velocity in age-related macular degeneration. Ophthalmology. 1995;102:640-646.
Macular Degeneration Foundation, 1999.
SIGNS and SYMPTOMS
Ophthalmologists can detect the presence of macular degeneration during a complete examination by observing the changes in and behind the retina. Small yellow clusters of deposits occur that can only be seen through an ophthalmoscope. Age related macular degeneration occurs in both eyes, is occasionally treatable, not preventable, and generally worsens over time. While some patients may have no symptoms, the symptoms most commonly seen include blurred central vision, decreased reading ability, especially in dim light, distortion in central vision, and trouble adapting to darkness. Macular degeneration occurs most often in patients over 50 years old.
This information is educational in context and is not to be used to diagnose,
treat or cure any disease. Please consult your licensed health care practitioner
before using this or any medical information.
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