![]() This randomized clinical trial was designed to evaluate the effect of high doses of zinc and selected antioxidant vitamins (5 to about 15 times the recommended dietary allowance 31) on the development of advanced AMD in a cohort of older persons. 30 Inconsistent evidence from observational studies, the small clinical trial of zinc and AMD, and the public health concern regarding the widespread use of unproven, high-dose antioxidant and zinc supplements for AMD led the National Eye Institute (National Institutes of Health, Bethesda, Md) to incorporate a clinical trial as part of the Age-Related Eye Disease Study (AREDS). 27 Despite the lack of convincing evidence, the marketing and use of antioxidants and zinc in eye-targeted formulations has become a common practice. One small, randomized, 2-year, placebo-controlled clinical trial of zinc supplementation found a statistically significant reduction in visual acuity loss in the zinc-treated group and recommended a more definitive trial before a general recommendation could be made for zinc supplementation in those at risk of vision loss from advanced AMD. 14 – 17 However, data from epidemiological studies 18 – 26 as well as small randomized clinical trials 27 – 29 do not show consistent associations between intake of antioxidants or zinc and risk of AMD. ![]() Oxidative damage to the retina may be involved in the pathogenesis of AMD. Other medical and surgical interventions are under investigation but none has been demonstrated as being effective in a large randomized clinical trial. Laser photocoagulation 5, 6 and photodynamic therapy 7, 8 reduce the risk of either moderate or severe visual acuity loss in some persons with the neovascular form of the disease. 1 – 4 At present, there is no proven treatment that slows or prevents the development of advanced AMD. No statistically significant serious adverse effect was associated with any of the formulations.Īge-related macular degeneration (AMD) is the leading cause of visual impairment and blindness in the United States and elsewhere among people 65 years or older. The only statistically significant reduction in rates of at least moderate visual acuity loss occurred in persons assigned to receive antioxidants plus zinc (OR, 0.73 99% CI, 0.54–0.99). ![]() Both zinc and antioxidants plus zinc significantly reduced the odds of developing advanced AMD in this higher-risk group. Participants with extensive small drusen, nonextensive intermediate size drusen, or pigment abnormalities had only a 1.3% 5-year probability of progression to advanced AMD. Comparison with placebo demonstrated a statistically significant odds reduction for the development of advanced AMD with antioxidants plus zinc (odds ratio, 0.72 99% confidence interval, 0.52–0.98). Average follow-up of the 3640 enrolled study participants, aged 55–80 years, was 6.3 years, with 2.4% lost to follow-up.
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