Risk of age-related macular degeneration in aspirin users and non-aspirin users: A population-based cohort study in Taiwan

Background: The association between cardioprotective aspirin and risk of age-related macular degeneration (AMD) is still controversial up to date. We aimed to analyze the risk of AMD between aspirin users and non-aspirin users. Method: This was a retrospective cohort study by using claims data from the National Health Insurance Research Database. Patients aged more than 45 years old who initiated aspirin during 2002 to 2012 were followed till 2013. We first selected an age and sex-matched cohort, then identified aspirin users and non-aspirin users as propensity score-matched cohort. Cox proportional hazard regression model was applied to compare their hazards and 95% confidence intervals. Incidence of newly developed AMD, neovascular AMD, and other-AMD was calculated. Results: We identified 204 085 regular aspirin users and 478 048 non-aspirin users from our datasets. The univariate HR was 2.85 (95% CI, 2.75-2.96), and the multivariate HR was 2.54 (95% CI, 2.44-2.65). In the PS-matched cohort, the HR was 2.38 (95% CI, 2.25-2.52). The incidence of aspirin users for AMD risk was 11.95 per 1000 person-year, while the incidence of non-aspirin users was only 3.92 per 1000 person-year. Conclusion: Patients with regular use of aspirin had higher risk in developing AMD compared to non-aspirin users and suggest to have regular visual acuity and funduscopic examination.