By Erin Hicks
Regular aspirin use can lead to eye damage later in life, found researchers from the University of Wisconsin in a new study, but that’s no reason to go off the aspirin just yet, say some doctors.
The Wisconsin study found that regular aspirin use for 10 years was associated with a statistically significant increase in the risk of a certain form of age-related macular degeneration (AMD), which results in the loss of vision in the center of the visual field due to damage to the retina.
Macular degeneration makes it harder to do things that require sharp central vision, like reading, driving, and recognizing faces. Since it doesn’t affect side vision, macular degeneration does not lead to complete blindness.
Barbara E.K.Klein, MD of the University of Wisconsin School of Medicine and Public Health and colleagues used data from the Beaver Dam Eye Study, a long-term population-based study of age-related eye diseases conducted in Wisconsin and found that regular aspirin use over a 10-year period was associated with a 63 percent increased risk of late AMD.
Eye exams were performed every five years over a 20-year period for almost 5,000 adults. Study participants were between the ages of 43 to 86 when they began the study. At exams, participants were asked if they had regularly used aspirin at least twice a week for more than three months.
Researchers measured the incidences of different types of AMD among the people in the study. There were 512 cases of early AMD and 117 cases of late AMD over the course of the study.
The estimated incidence of late AMD was 1.76 percent in regular aspirin users compared with 1.03 percent in non-users.
The incidence of late AMD was also higher with five years of aspirin use, but the finding was not statistically significant, researchers found.
Researchers found no relationship between 10-year use of any nonsteroidal anti-inflammatory drugs or warfarin and the risk of AMD.
The study was published in the Dec. 19 issue of the Journal of the American Medical Association.
Unclear Link Between Aspirin and Macular Degeneration
Some retina specialists were surprised at the study findings when it was first suggested about a year ago that there might be a link between aspirin and AMD, says Dr. Robert Cykiert, MD, Clinical Associate Professor, Department of Ophthalmology at New York University. “Many retina doctors did not believe this was true because they have never seen anything like it in their practice. Not only that, there is no obvious mechanism for how aspirin would affect AMD,” says Dr. Cykiert. “Unless there’s something hidden about AMD that we don’t understand yet, there doesn’t seem to be a logical explanation for it, so we tend to doubt it before we have more evidence.”
The study had room for error too, says Cykiert. While it involved many patients over a long period and included statistical analysis, the patients who were studied were mostly of European descent. It's possible that in a group of people with similar DNA, there could be more genetic susceptibility to AMD.
He also points out that the study was retrospective and relied to a great degree on patients reporting their aspirin intake over a long period of time. “My patients take Tylenol and some think it’s the same thing as aspirin, so there is room for error here in what the patients reported,” says Cykiert.
Lifestyle Factors That Could Contribute to AMD
There are known risk factors for AMD. “There’s an association with cigarette smoking — those who smoke have an early onset of AMD and it progresses more rapidly,” says Cykiert.
He also says diet could play a role — those who eat leafy green vegetables and fruits seem to have less of a risk of developing AMD and milder cases if they develop it. “We believe a diet that’s high in vegetables, fruits, antioxidants, and vitamins has a protective role in preventing the development of AMD,” he says.
And don’t forget to wear shades when you go outside — there is some evidence that UV light may have a toxic effect on the retina over decades of exposure. “We advise people to wear sunglasses outdoors that have UV block or UV prevention, which can also protect against cataract formation,” Cykiert says.
Don’t Go Off the Aspirin Just Yet
It’s very important not to stop aspirin treatment if your doctor has ordered it, Cykiert emphasizes.
“I have many elderly patients who were prescribed an aspirin treatment by their doctors to help prevent a stroke or heart attack and I think it would be a huge mistake if they stopped the treatment because of this study,” he says. “Until we have more evidence and before more testing is done, don’t stop your aspirin.”
"Aspirin and Eye Damage: Docs Say Don't Stop Treatment Yet" originally appeared on Everyday Health.