Scientists have found those who take aspirin on a regular basis are much more likely to develop ‘wet’ age-related macular degeneration (‘wet AMD’) than those who do not. The disease, in which one’s central vision becomes progressively more blurred, affects a quarter of a million mainly elderly people in Britain. Now scientists have found the strongest evidence yet that aspirin – taken by millions to ward off heart attacks, strokes and cancer – appears to greatly increase the chance of developing wet AMD, which is irreversible. Australian academics drew their conclusions after following almost 2,400 middle-aged and elderly people for 15 years.
Of the participants, who were all at least 49 years old at the start of the study, 257 were deemed “regular” users of aspirin, who took it at least once a week. The rest only took it occasionally.
After the 15 year study period, one in 27 of the ‘occasional’ users (3.7 per cent) had developed wet AMD.
But almost one in 10 of the ‘regular’ users (9.4 per cent) had developed it. Writing in the Journal of the American Medical Association (JAMA), the researchers concluded: “Regular aspirin use was significantly associated with an increased incidence of neovascular [wet] AMD.” Sight charities said doctors should bare the findings in mind when advising patients on whether or not they should take aspirin as a preventive medicine, particularly those who already had wet AMD in one eye.
Taken at a low daily dose to prevent heart attacks and strokes, aspirin is enjoying a resurgence due to recent studies strongly indicating it can fight cancer. Oxford University researchers have found it reduces the incidence of some cancers by a third, while it also retards the growth of tumours. However, aspirin has long been known to have side effects, most prominently increasing the risk of intestinal bleeds, which can cause ulcers. Today’s study, by a team at Sydney University, suggests people should also consider the possible effect on their sight.
It builds on previous evidence suggesting aspirin could increase the chance of developing wet AMD. A little over a year ago, researchers working on the European Eye Study found that aspirin doubled the risk of advanced wet AMD, which leads to the most profound blindness. However, the researchers admitted they could not conclude that aspirin caused the disease, because it was a ‘cross-sectional’ study which did not follow people over time. By contrast, the Australian study provides more robust observational evidence of a link, although it is not conclusive. The academics behind today’s study did not think their research warranted changing clinical guidelines though, saying there was still “insufficient evidence” to do so “except perhaps in patients with strong risk factors for neovascular [wet] AMD”.
That approach was mirrored last night by sight charities. A spokesman for the Macular Society said: “The evidence is now accumulating about the association of aspirin and wet AMD. However, it is not overwhelming at this point. “For patients at risk of cardiovascular disease, the health risks of stopping or not prescribing aspirin are much higher than those of developing wet AMD. There are treatments for wet AMD as long as it is diagnosed in time.” She added: “Patients with wet AMD in one eye should have their other eye carefully monitored so that any sign of wet AMD can be found quickly. Potential risks to the eye need to be discussed between the patient and their doctors.” She also emphasised that a patient should always talk to their doctor before making a decision to stop taking aspirin prescribed to them. Matthew Athey, of the RNIB, described the study as “interesting research”. He said: “Further research is needed to clarify and investigate some of the issues raised in the study; however this association may be valuable for doctors in the future when considering aspirin for their patients.”