Purpose
To resolve the conflict of Aspirin's cardiovascular benefits versus its possible adverse effects on age-related macular degeneration (AMD). Aspirin's overall beneficial effects in reducing heart attacks, stroke and sudden death have long been documented in many large, randomized, controlled trials. Recent data from two smaller AMD epidemiology studies have suggested a deleterious effect on vision in patients with age-related macular degeneration. A balanced analysis of these competing data sets is needed to resolve these issues and aid cardiologists and ophthalmologist in appropriately counseling their patients.
Methods
A meta-analysis was performed of six large randomized, controlled trials using aspirin as a preventive for cardiovascular events compared to smaller AMD epidemiological trials evaluating the effects of aspirin on age-related macular degeneration. The cardiovascular prevention studies consisted of a total of 95,000 individuals. The AMD epidemiological studies consisted of 13,062 participants collectively.
Results
The combined meta-analyses showed aspirin caused a 32 % reduction in the risk of non-fatal stroke (OR:0.68, 95% CI, 0.59-.79) with regular aspirin users. The study also documented that aspirin users decreased the risk of vascular events by 15 % (OR:0.85, 95 % CI, 0.79-0.93). In the AMD epidemiological studies, Aspirin was associated with the increase in neovascular AMD from 1.9 % in five years, 7 % in ten years, and 9.3 % in fifteen years in regular aspirin users (OR: 2.46, 95 % CI: 1.25-4.83). It is important to note that the odd ratios are significantly smaller in the larger cardiovascular prevention trials than the odd ratios in the smaller AMD epidemiological studies.
Conclusions
Overall, the size and quality (very small confidence intervals) of the cardiovascular studies documenting the overall health benefit of aspirin use is much greater than the few smaller AMD epidemiological studies suggesting possible adverse vision effects of aspirin use in age-related macular degeneration. The benefits of aspirin usage include preserving the duration and quality of life by decreasing stroke and heart attack risk. These benefits seem to far outweigh the theoretical risks of possibly exacerbating wet AMD that can be reasonably controlled with anti-VEGF therapy. We strongly recommend that AMD patients should be on aspirin if it is recommended by their primary physician.