Singapore: People who regularly took aspirin for 10 years had a statistically significant increase in the risk of a subtype of age-related macular degeneration (AMD), according to a study by University of Wisconsin (UW) School of Medicine and Public Health researchers.

Dr Barbara Klein and her collaborators studied nearly 5,000 people, who took part in the UW School of Medicine and Public Health's Beaver Dam Eye Study. "Aspirin use in the US 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. The study was funded by the National Eye Institute. 

Dr Klein looked at data from eye exams performed on Beaver Dam participants every five years over a 20-year period (1988-1990 through 2008-2010). There were 512 cases of early age-related macular degeneration and 117 cases of late AMD over the course of the study. The researchers found that regular aspirin use 10 years before the retinal exam was associated with late AMD (age and sex-adjusted incidence, 1.8 percent for users as compared to one percent for nonusers).

They found a significant association with one subtype of late AMD, neovascular AMD (age-and sex-adjusted incidence, 1.4 percent for users compared with 0.6 percent for nonusers). There was no significant association for the other subtype or for early age-related macular degeneration.

"Our findings are consistent with a small but statistically significant association between regular aspirin use and incidence of neovascular AMD," the authors wrote. They said that if further studies confirm the link, it will be important to develop ways to block or slow the effect, especially for people who use aspirin to prevent cardiovascular disease.