HealthDay News — Regular aspirin use is associated with an increased risk of developing neovascular age-related macular degeneration (AMD), with evidence of a dose-response effect, results from an Australian study suggest.
Aspirin users had a 2.37 odds ratio for developing AMD (95% CI: 1.25 to 4.49), after adjusting for age, sex, and history of smoking, Gerald Liew, PhD, from the University of Sydney in Australia, and colleagues reported in JAMA Internal Medicine.
Risk for AMD remained elevated after adjusting for additional factors, including BMI, systolic BP, and history of cardiovascular disease (OR=2.46; 95% CI: 1.25-4.83).
The researchers analyzed data from the Blue Mountains Eye Study, a 15-year prospective cohort study, to examine the correlation between aspirin use and the risk for developing AMD in 2,389 participants aged 49-years and older. At baseline, participants completed a detailed questionnaire relating to aspirin use, cardiovascular disease status and AMD risk factors.
Patients underwent retinal examination every five years, and lesions were classified as neovascular macular degeneration, also known as wet AMD, or as geographic atrophy, known as dry AMD. The study included 257 regular aspirin users, who were older and more likely to have conditions such as diabetes, cardiovascular disease or elevated BP.
A total of 63 patients had neovascular AMD during 15 years of follow-up. Among regular aspirin users, the cumulative incidence was 1.9%, 7% and 9.3% at years 5, 10 and 15, while the incidence among nonusers was 0.8%, 1.6% and 3.7%, respectively.
The incidence of neovascular AMD rose with more frequent aspirin use, increasing from 2.2% in those who never took aspirin, to 2.9% for those who used it only occasionally, and 5.8% for those who took aspirin routinely.
There was no correlation between aspirin use and geographic atrophy.
Aspirin is a commonly used, effective treatment to prevent secondary cardiovascular disease, but regular users are at increased risk for significant adverse events including, cerebral and gastrointestinal bleeding, the researchers noted.
“Our present study now raises the possibility that the risk of neovascular [age-related macular degeneration] may also need to be considered,” Liew and colleagues wrote.
However, they acknowledged that the risk was relatively small at 4% during 15 years of follow-up and is not yet sufficient to support limiting widespread aspirin use in clinical practice, except for patients at very high risk for macular degeneration.
In an accompanying editorial, Sanjay Kaul, MD, and George A. Diamond, MD, of Cedars-Sinai Medical Center in Los Angeles, wrote “the evidence is insufficient to adjudicate the relationship between aspirin and [age-related macular degeneration], thereby challenging causal inferences.”
They emphasized the findings need to be validated in prospective randomized studies before being considered to guide clinical practice or patient behavior.
“In the final analysis, decisions about aspirin use are best made by balancing the risks against the benefits in the context of each individual’s medical history and value judgments,” Kaul and Diamond wrote.