Aspirin use and risk of cataract in posttrial follow-up of Physicians' Health Study I.

BACKGROUND In Physicians' Health Study I, randomized trial results indicated no major beneficial effect of 5 years of low-dose aspirin treatment on total cataract (relative risk [RR], 0.94; 95% confidence interval [CI], 0.79-1.13) or cataract extraction (RR, 0.81; 95% CI, 0.65-1.01) during the period of treatment. OBJECTIVE To examine the effect of assigned aspirin treatment and posttrial, self-selected aspirin use on the risk of age-related cataract over the 15 years of follow-up of Physicians' Health Study I. METHODS Participants were 20 968 US male physicians enrolled in Physicians' Health Study I who did not report cataract at baseline. At 7 years, after termination of the randomized aspirin component of the trial, self-selected aspirin use was computed from annual questionnaires. The main outcome measures were age-related cataract and extraction of age-related cataract, defined as an incident, age-related lens opacity responsible for a reduction in best-corrected visual acuity to 20/30 or worse based on self-report confirmed by medical record review. RESULTS During a median of 14.9 years of follow-up, there were 2081 cataracts and 1198 cataract extractions. Overall, the age- and beta carotene-adjusted RR of cataract in men assigned to aspirin compared with those assigned to placebo was 1.09 (95% CI, 1.00-1.18). For cataract extraction, the RR was 1.09 (95% CI, 0.98-1.22). During a median posttrial follow-up of 7.9 years, a total of 1225 incident cataracts and 635 cataract extractions were documented. The multivariate RR of cataract in men who reported using aspirin frequently (>/=180 days per year) at 7 years compared with nonusers (0-13 days per year) was 1.20 (95% CI, 1.03-1.40). For cataract extraction, the multivariate RR was 1.22 (95% CI, 0.98-1.51). Results for diagnosis and extraction of cataract subtypes were similar. CONCLUSIONS Analyses based on randomized aspirin assignment indicated no long-term benefit of 5 years of low-dose aspirin treatment on total cataract or cataract extraction. Posttrial, observational data also indicated no decreased risk of cataract in aspirin users and suggested a small increased risk of cataract in aspirin users. Further randomized trial data to investigate the effect of longer term treatment with low-dose aspirin are being collected as part of the ongoing Women's Health Study, a randomized trial of low-dose aspirin and vitamin E among 39 876 apparently healthy, postmenopausal US female health professionals.