Extended exposure to sunlight may be related to the development of certain age-related eye diseases
CHICAGO – Extended exposure to summer sunlight in early adulthood may increase the risk for developing age-related maculopathy, an eye disorder that can cause blindness, according to an article in the May issue of The Archives of Ophthalmology, one of the JAMA/Archives journals.
According to background information, age-related maculopathy (ARM) is the leading cause of vision loss in older Americans, and few therapies exist to treat patients with this disease. ARM is characterized by the growth of abnormal blood vessels on the retina (the light-sensitive layer of cells at the back of the eye), the development of drusen (opaque deposits on the retina), and increased retinal pigment.
Sandra C. Tomany, M.S., of the University of Wisconsin Medical School, Madison, and colleagues examined the association between sunlight exposure and sunlight sensitivity and the ten-year incidence of ARM among people aged 43 to 86 years who were first examined between 1988 and 1990 as part of the Beaver Dam Eye Study. Of the total participants, 3,684 were followed up for five years, and 2,764 were followed up for ten years.
Information on sun exposure and indicators of sun sensitivity was collected at the beginning of the study and/or during follow-up visits.
Participants who reported being exposed to the sun for more than five hours a day during their teens, 30s, and at the beginning of the study were three times as likely to develop increased retinal pigment and were more than twice as likely to develop early ARM within ten years compared to participants who reported being exposed to less than two hours per day of sunlight during the same periods.
In participants who reported being exposed to the most sunlight, the use of hats and sunglasses at least half the time was associated with an approximately 50 percent lower risk of developing drusen and retinal pigment. Participants who reported more than ten severe sunburns during their youth were 2.5 times more likely than those who experienced one or no sunburns to develop drusen within ten years.
However, "No relationships were found between UV-B exposure, winter leisure time spent outdoors, skin sun sensitivity, or number of bad sunburns experienced by the time of the baseline examination and the 10-year incidence and progression of ARM or its associated lesions [drusen, etc]."
Source: Eurekalert & othersLast reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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