The Age-Related Eye Disease Study (AREDS) included 4,757 participants, ages 55-80 years, with cataract, AMD, or both. AMD results are based on 3,640 participants who had early or worse AMD. Cataract results are based on 4,629 of the participants with cataract in one or both eyes.
AREDS included participants with AMD ranging from none in either eye to advanced AMD in one eye but good vision (at least 20/30) in the other eye. The participants were enrolled at 11 clinics nationwide and their clinical progression was followed for 5 years. Fifty-six percent were female. The median age was 69 years. Enrollment began in November 1992 and ended in January 1998.
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Participants in each category were randomly selected to receive daily oral tablets for one of four treatments:
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The antioxidant formulation contained a combination of the following nutrients:
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AREDS scientists found that people at high risk for developing advanced AMD—those with intermediate AMD, and those with advanced AMD in one eye only—reduced their risk of developing advanced by about 25 percent when treated with the combination of antioxidants and zinc + copper (final AREDS formula). The AREDS formula also reduced the risk of central vision loss by 19% in the same group. None of the formulations decreased cataract risk.
AREDS investigators followed participants for an additional five years. Ten years after enrollment, about 70% of participants were taking the antioxidants plus zinc + copper formulation (AREDS formula). The investigators found that participants who had been assigned to antioxidants plus zinc + copper formulation in the trial were 25-30% less likely to develop advanced AMD than those who had originally been assigned to placebo. Among participants at the highest risk for AMD, 34% who had taken the antioxidants plus zinc + copper (AREDS formula) in the trial progressed to advanced AMD, compared to 44% who had taken the placebo.
