Regular aspirin use may increase your chance of getting an eye disorder called age-related macular degeneration (AMD), according to a new study.
Subjects who said they used aspirin regularly 10 years before the study were shown to have a stastistically significant increase in certain types of AMD.
About 19.3 percent of U.S. adults use aspirin regularly -- defined as using aspirin twice a week for more than three months -- according to the researchers.
AMD is an eye condition normally found in people over 50 that causes loss in vision by affecting the macula, the part of the eye that controls sharp, central vision needed for seeing objects clearly. Smoking, being Caucasian or family hisotry has been known to increase the chance of getting AMD, but previous studies connecting aspirin use with AMD have been inconclusive.
"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," the researchers wrote. "Therefore, it is imperative to further examine this potential association."
Researchers looked at data from 4,926 subjects who were part of the Beaver Dam Eye Study, a population-based study in Wisconsin that looked at age-related eye diseases. Study participants were 43 to 86 years old at the time of the start of the study. They had regular eye exams every five years over a 20-year period.
Researchers found there were 512 incident cases of early AMD and 117 incident cases of late AMD over the course of the study. Those who reported using aspirin regularly 10 years prior to the study had a 1.8 chance of late AMD when adjusted for age and sex, compared to only 1 percent for those who didn't use aspirin.
Within the late AMD category, aspirin users had a 1.4 percent chance of getting a type of AMD known as wet or neovascular AMD, compared to 0.6 percent of people who did not take the medication. It is more serious than the other type of late AMD known as dry AMD and affects 10 percent of AMD patients, according to the National Institutes of Health.
Researchers pointed out that percentages were so low because the risk of getting this type of the disease was relatively low. However, since people had a more than twice as likely chance of getting neovascular AMD if they regularly used aspirin, it was stasticially significant.
Those who used aspirin five or 10 years prior to the study did not have a significantly increased chance of getting early AMD.
"This study is suggestive that there may be a relationship but it is by no means definitive," Dr. George Williams, professor and chair of the department of ophthalmology at Oakland University's William Beaumont School of Medicine in Rochester, Mich., told WebMD. He was not involved in the study.
Williams added the results were not as strong because people self-reported their aspirin use. If a cardiologist recommended aspirin to help prevent heart disease, he said he "would not take any off it."
However, Dr. Gregg Fonarow, a professor of cardiology at the University of California, Los Angeles, said to HealthDay it was not time to stop advising people to use aspirin because controlled trials of aspirin use for up to 10 years have not shown any increased rate of ASD.
"For most patients, the benefits of regular low-dose aspirin use outweigh the potential risks," Fonarow said. "Individuals prescribed aspirin for primary or secondary cardiovascular prevention should not be concerned or discontinue this beneficial therapy."
The study will be published in JAMA on Dec. 19.