Is Aspirin Safe for AMD Patients?
A recent research paper in
Journal of the American Medical Association reports that regular
aspirin use may slightly increase the risk of advanced age-related macular
degeneration (AMD). But many experts, including the paper’s authors, say that
people with AMD should not stop taking aspirin for treatment of cardiovascular
disease or as prescribed by a doctor for other health issues.
Studies of AMD and aspirin have been prompted by the concern that aspirin might increase the risk of vision-robbing hemorrhaging beneath the retina that is the hallmark of the wet form of AMD. The latest report comes from the Beaver Dam Eye Study, named for a town in Wisconsin which, since 1987, has been the setting of a longitudinal study collecting prevalence, incidence, and risk-factor data for age-related eye disease, including AMD. The study is funded by the National Eye Institute (NEI).
Dr. Emily Chew, deputy director of the Division of Epidemiology and Clinical Applications at the NEI, says that previous studies of aspirin and AMD risk have yielded conflicting or inconclusive results. However, she, too, says that aspirin is safe for AMD patients.
“The totality of evidence from both the observational studies and the randomized controlled clinical trials of aspirin would suggest that there is no major harmful association of aspirin use with AMD,” says Dr. Chew. “Persons affected with AMD should consider aspirin when medically indicated.”
At the American Academy of Ophthalmology’s Retina 2012 meeting held in Chicago in November, Dr. Chew reported on aspirin use and AMD for participants from the Age-Related Eye Disease Study (AREDS), as well as the follow-up study AREDS2. Dr. Chew is study chair for AREDS2. Data from those two observational research studies comprising nearly 7,000 participants showed that aspirin use did not increase the risk of developing advanced age-related macular degeneration.
Dr. Chew also noted that two controlled clinical trials — the Women’s Health Study and the Physicians’ Health Study — showed that aspirin use, if anything, decreased the risk of developing AMD. Results from controlled clinical trials are often considered more definitive than results from observational studies, because the study investigators are monitoring the use of the treatment in question. Observational studies, like the one conducted in Beaver Dam, are retrospective; participants are interviewed about their previous lifestyle or treatment habits.
“In many of the studies that suggest risk, it isn’t clear whether aspirin use actually causes the slight increase in advanced AMD or it just correlates with the risk,” says Dr. Stephen Rose, chief research officer, Foundation Fighting Blindness. “As the Beaver Dam research team notes, there could be a number of other risk factors involved that aren’t being considered in their observational studies. Regardless, I strongly encourage AMD patients with questions to consult with their cardiologist or doctor who advises them to take the aspirin, because it's most likely for a heart issue."