Age-related maculopathy in a randomized trial of low-dose aspirin among US physicians

To examine the development of age-related maculopathy (ARM) in a large-scale trial of low-dose aspirin treatment.

The Physicians' Health Study I was a randomized, double-masked, placebo-controlled trial of low-dose aspirin (325 mg every other day) and beta carotene (50 mg every other day) in the prevention of cardiovascular disease and cancer conducted among 22 071 US male physicians aged 40 to 84 years in 1982. A total of 21 216 participants did not report ARM at baseline, were followed up for at least 7 years, and are included in this analysis.

Total ARM, defined as a self-report confirmed by medical record evidence of an initial diagnosis subsequent to randomization, and ARM with vision loss, defined as total ARM but with vision loss to 20/30 or worse attributable to ARM.

Early termination of the randomized aspirin component of the Physicians' Health Study I, after an average of 60.2 months of treatment and follow-up due to a statistically extreme 44% reduced risk of first myocardial infarction, resulted in a far lower number of incident cases of ARM during the aspirin treatment period than would have accrued without early termination. Thus, during an average of 60.2 months of follow-up, a total of 117 cases of ARM were confirmed, including 57 cases responsible for vision loss to 20/30 or worse. There were 51 cases of ARM in the aspirin group and 66 in the placebo group (relative risk, 0.77; 95% confidence interval, 0.54-1.11). For ARM with vision loss, there were 25 cases in the aspirin group and 32 in the placebo group (relative risk, 0.78; 95% confidence interval, 0.46-1.32).

These randomized trial data tend to exclude any large beneficial effect of 5 years of low-dose aspirin treatment on ARM. However, a smaller, but potentially important, beneficial effect cannot be ruled out and would require testing in randomized trials of adequate size and duration.