longevity and eye disorders
May 10, 2004 — Older people with age-related macular degeneration or cataracts may live shorter lives than those without such eye disorders, according to new research.
The study showed that people with evidence of these eye disorders were more likely to die of any cause within a six-and-a-half year follow-up study than those with healthy eyes. In addition, people with advanced age-related macular degeneration (AMD) were also more likely to die of heart disease than others.
Researchers say the results suggest that eye disorders, such as AMD and cataracts, may reflect other underlying health problems that cause sufferers to have a shorter life span.
Eye Problems Linked to Poor Survival
Macular degeneration is the No. 1 cause of vision loss in the U.S. Deposits form under the retina, and in some cases abnormal blood vessels grow under the retina. Sufferers lose central vision, but it does not affect side vision.
In the study, which appears in the May issue of The Archives of Ophthalmology, researchers followed a group of nearly 5,000 people aged 55 to 81 who were participants in the Age-Related Eye Disease Study (AREDS), a long-term study which looked at the progression of cataract and age-related macular degeneration and also looked at the use of antioxidants. Participants were randomly assigned to take high-dose antioxidants, zinc, antioxidants plus zinc, or placebo.
During the six-and-a-half year follow-up period, 534 of the participants died.
The study showed that those with AMD had about a 41% higher risk of death during the study compared with those with little or none of the opaque deposits under the retina commonly associated with macular degeneration. More severe degrees of AMD were associated with cardiovascular deaths.
Those with vision worse than 20/40 (an indicator of visual impairment) in one eye and those who had cataract surgery also had an increased risk of death, 36% and 55%, respectively.
The study also showed that patients who had been randomly assigned to take zinc supplements, either alone or in combination with other supplements, had about a 27% lower risk of death than those who didn’t take zinc.
The researchers say that other studies have reported a beneficial effect of zinc in improving immunity and resistance to infections in the elderly. They say it is possible that the beneficial effects of zinc on the decreased risk of death in this study may be related to an improved immune response, which decreases with aging.
“The decreased survival of AREDS participants with AMD and cataract suggests that these conditions may reflect systemic rather than only local processes,” write Tracry E. Clemons, PhD, and colleagues in the AREDS Research Group. “The improved survival in individuals randomly assigned to receive zinc requires further study.”