Long-term aspirin use ‘increases blindness risk’

This cohort study has suggested that there may be a link between aspirin use and risk of developing wet AMD. The main strengths of this study are that it followed people up over a long time, collected data prospectively and carried out thorough eye examinations for AMD. This means that cases of AMD were not likely to be missed. However, it should be noted that:

The study’s main weakness was that, as a cohort study, its results may be affected by confounding, although the researchers did try to take into account factors that could be having an effect. Confounding ‘by indication’ is a possibility; this is where the reason for taking the aspirin may be influencing the results, rather than the aspirin itself. The researchers controlled for this by taking into account cardio…
Source: Blindness