SAN FRANCISCO — A large European study released Tuesday found that daily aspirin use is linked to an increased risk of age-related macular degeneration, a disease that can damage the central vision that is essential for reading and driving. The study was published in the January issue of Ophthalmology, the journal of the American Academy of Ophthalmology.
The study found that people aged 65 years and older who took aspirin daily had double the risk of developing "wet" AMD, compared with those who took it less frequently. Wet AMD, an advanced form of the disease, is a major cause of blindness in older people in the United States, Europe and other regions. The damage occurs when abnormal blood vessels grow and bleed or leak fluid into the macula, the center of eye's retina. The study also found a somewhat elevated risk of early-stage AMD in daily aspirin users.
No higher risk was found for advanced "dry" AMD. Although dry AMD is the most common form of the disease, only a minority of patients develop the advanced stage. In those who do, vision loss occurs gradually as the macula develops abnormal deposits called drusen and eventually becomes too thin and eroded to function.
In this study, the 839 participants who reported taking aspirin every day had higher rates of cardiovascular disease, were less likely to be smokers and were older than participants who took aspirin less often. Since cardiovascular disease itself is a risk factor for AMD, the researchers carefully analyzed whether participants' heart health had impacted the study's outcomes. But even when cardiovascular status was factored in, the results showed higher risk for wet AMD in daily aspirin users, researchers noted.
The researchers said they think medical professionals should stick with their current advice on aspirin for older cardiovascular disease patients until other studies confirm the link between daily aspirin use and wet AMD risk.
"If future studies support our results, then recommendations on aspirin may need to be modified for patients with age-related macular degeneration," stated Paulus de Jong of the Netherlands Institute for Neuroscience and Academic Medicine, who led the research team. "It's possible that increased AMD risk may outweigh aspirin's potential protective benefits for some patients, but we need to know more about the impacts of dose, length of use and other factors before we can say for certain or make specific recommendations."
De Jong's research was part of the European Eye Study that examined and surveyed more than 4,600 Europeans between 2000 and 2003. The study's main goals were to estimate AMD prevalence and to investigate the impacts of sun exposure and antioxidant vitamin use on disease development.