Eye Vitamins

The next (June 10th) issue of The Medical Letter will include an article on the results of the long-awaited AREDS2 trial, which were published in the May 15th issue of the Journal of the American Medical Association (JAMA). AREDS stands for Age-Related Eye Disease Study. The first AREDS trial, which was sponsored by the National Eye Institute and Bausch and Lomb, recruited 3640 patients 55-80 years old who had age-related macular degeneration and randomized them to treatment with several antioxidant vitamins, zinc or both, or to a placebo. A subgroup of patients who had the most advanced disease were singled out in assessing the results; among these patients, the probability that they would lose at least 3 lines of vision in at least one eye over 5 years was 29% with placebo and 23% with both antioxidants and zinc, a statistically significant difference. Patients treated with antioxidants or zinc alone did not show a significant difference in outcome from those treated with placebo.

Manufacturers of ophthalmic drugs subsequently promoted the use of these agents for prevention of eye disease and were not always careful to remind practitioners that only patients with moderately advanced macular degeneration had shown any benefit. Since both vitamins and zinc are considered nutritional supplements, and not drugs, the FDA had only limited power over their promotion. One concern did come up about widespread use of these agents: 2 prospective, randomized, placebo-controlled trials had shown that high doses of beta carotene increased the risk of lung cancer in smokers. That led to the idea of replacing beta carotene with something else.

And so now we have AREDS2, an even more complicated clinical trial than AREDS1. This time, though, for whatever reasons, Bausch and Lomb is no longer a co-sponsor. Does that matter? Will the new agents replacing beta carotene be as effective? Did the investigators include a placebo group that could confirm the results of AREDS1? Read all about it in our next issue. Or check out the complete results in JAMA, and then look for our interpretation. It might not be the same as the authors’.

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