By Prateek Buch, on 24 January 2013
A number of recent media stories have highlighted two studies examining the link between long-term use of aspirin and the risk of developing the “wet” form of age-related macular degeneration (AMD). Because some of the headlines are misleading, we would urge you to consider the following details about the studies and the advice that follows.
In a study published last December in the Journal of the American Medical Association, specialists at the University of Wisconsin followed the vision of nearly 5000 patients over a period of fifteen years. They found that those who were prescribed daily aspirin to protect against heart disease were more likely to develop the “wet” form of AMD (in which the growth of new blood vessels damages the retina) than those who didn’t take aspirin. However, the risk of developing wet AMD rose from around 1-in-100 to just over 1-in-60 – which is a small difference in a rare risk.
A study from the University of Sydney, published in January 2013 in the separate journal JAMA Internal Medicine, showed that 4% of people who did not take aspirin regularly developed wet AMD, whilst 9% of those who took aspirin daily for ten years developed the condition.
While these studies suggest an association between long-term aspirin use and increased risk of AMD, they do not tell us whether any relationship is causative. Previous studies looking at the link between aspirin and AMD have been inconclusive. There is not yet enough evidence to know whether the increased risk of wet AMD is caused by aspirin itself or by other health factors for which aspirin is used.
Commenting on the media stories linking aspirin and AMD, Professor James Bainbridge said, “Daily aspirin use is well-established as an effective way to protect against heart disease in people at high risk. We therefore support the advice given by the Macular Society and others, which advises those who take aspirin to lessen their risk of heart attacks to continue to do so. Given that wet AMD can be managed using drug therapy, and that aspirin use can significantly reduce the risk of heart disease, there is no need as yet to change aspirin use based on these studies.”