The evidence of aspirin’s effect on AMD is mixed, with some studies finding a deleterious effect and others no harm at all. To learn more, researchers surveyed a random cross-section of 4,691 subjects, age 65 and older, throughout Europe about aspirin use, medical history, socioeconomic background, smoking and alcohol consumption. They found that daily aspirin users were twice as likely to have wet AMD.
They also found that frequent aspirin use was associated with both early AMD and wet late AMD. The odds ratios rose with increasing frequency of consumption across all grades of AMD, with the exception of grade 3 disease. After adjusting for all known confounders, including cardiovascular disease or angina, the association remained. No association or trend was found between aspirin intake and dry AMD, but the number of cases in this series was small.
For daily aspirin users with grade 1 disease the odds ratio was 1.26; grade 2, 1.42, and late AMD, 2.22.
The authors note several potential limitations of this study, including the inability to exclude the possibility that people with AMD took aspirin after experiencing visual problems, and the inability to completely rule out all confounding factors despite efforts to eliminate the potential influence of cardiovascular disease or angina.
The authors don’t suggest telling patients to stop taking aspirin. However, they do note that a recent meta-analysis of major trials shows that there is an increase in hemorrhagic stroke, gastrointestinal bleeds, and extracranial bleeds in patients randomized to aspirin, which led the authors to conclude that for primary prevention of coronary heart disease, there was little net benefit of aspirin because of its adverse effects. In addition, other studies have shown that wet AMD patients taking aspirin are at risk of intraocular hemorrhages.
Like the authors of these previous studies, they say they are simply alerting attention to the possible adverse effect of aspirin on AMD and hoping to stimulate other studies with data on aspirin use and AMD to investigate these effects.