Does long-term aspirin use increase the risk of neovascular age-related macular degeneration?

INTRODUCTION: Aspirin is used regularly for rheumatoid pain management and cardioprotection. However, aspirin has also been associated with significant adverse events, such as cerebral and gastrointestinal bleeding. Recent findings from several observational epidemiologic studies indicate that regular aspirin use may also be associated with increased risks of some forms of age-related macular degeneration (AMD). AREAS COVERED: In this report, we review recent findings from observational epidemiologic studies suggesting a possible adverse effect of regular aspirin use in AMD, and in particular, neovascular AMD. These findings are considered in light of the relative strengths and limitations of observational studies and randomized trials. EXPERT OPINION: While the findings are important and warrant further investigation, the inherent limitations of observational studies, most notably uncontrolled confounding, preclude an interpretation of causality. Alternatively, the most reliable evidence with which to evaluate the effects of regular aspirin use in AMD will derive from well-designed randomized trials of sufficient size and duration. Such information is unlikely to alter current recommendations for persons at high risk of cardiovascular disease, but should help clarify the benefit-to-risk ratio of regular aspirin use in the large majority of individuals at low-to-moderate risk.