A new study suggests a "small but statistically signifcant" increase in age-related macular degeneration among study participants who used aspirin reguarly for at least 10 years.
In the study, published in the December 19 issue of JAMA, researchers examined the records of nearly 5,000 individuals and recommended additional study to find the cause of the apparent increase in the potentially-blinding disease among aspirin users.
“Our findings are consistent with a small but statistically significant association between regular aspirin use and incidence of neovascular AMD. Additional replication is required to confirm our observations. If confirmed, defining the causal mechanisms may be important in developing methods to block this effect to prevent or retard the development of neovascular AMD in persons who use aspirin, especially to prevent CVD,” the authors conclude.
Barbara E. K. Klein, M.D., M.P.H., of the University of Wisconsin School of Medicine and Public Health, Madison, and colleagues used data from the Beaver Dam Eye Study, a longitudinal population-based study of age-related eye diseases conducted in Wisconsin.
Examinations were performed every 5 years over a 20-year period. Study participants were 43 to 86 years of age at entry in the study. At subsequent examinations, participants were asked if they had regularly used aspirin at least twice a week for more than 3 months. The average duration of follow-up was 14.8 years.
“Aspirin use in the United States is widespread, with an estimated 19.3 percent of adults reporting regular consumption, and reported use increases with age,” according to background information in the study. “AMD is a potentially blinding condition for which prevalence and incidence are increasing with the increased survival of the population, and regular use of aspirin is common and becoming more widespread in persons in the age range at highest risk for this disease. Therefore, it is imperative to further examine this potential association.”
For the study, the researchers measured the incidences of different types of AMD (early, late, and 2 subtypes of late AMD [neovascular AMD and pure geographic atrophy]).
There were 512 incident cases of early AMD and 117 incident cases of late AMD over the course of the study. The researchers found that regular use of aspirin use 10 years prior to the retinal examination was associated with late AMD. When examining the relationships by late AMD subtype, neovascular AMD was significantly associated with such use, but not for pure geographic atrophy. Aspirin use 5 years or 10 years prior to retinal examination was not associated with incident early AMD.