Aspirin and AMD

An elderly patient of mine came into the office the other day for a spectacle adjustment. We all have this patient in our practice: an 83-year-old silver-haired grandma, hunched over her walker from osteoporosis, with little cigarette burn marks tattooing her blouse. She spotted me as I came out the exam room and motioned for me to come over. The cigarette odor grew stronger with each approaching step.

“Ernie, have you got a minute?” she asked.

“I always have time for you, young lady,” I replied.

“I saw something the other day on the TV that said this aspirin I'm takin’ could make me go blind!” she exclaimed. “Is that true?””

I doubt I'm the only optometrist who’s had this conversation with one of their patients of late. There has been much in the media recently about two studies concerning aspirin and age-related macular degeneration. Our editor in chief Gretchyn Bailey has an article in this issue about just that topic. Daily aspirin therapy is usually recommended only for people who have had a previous heart attack or stroke, and only in accordance with their physician’s guidance.¹

A study by Dr. Barbara Klein and others in the December 2012 Journal of the American Medical Association² analyzed data from 4926 participants of the Beaver Dam Eye Study. The participants, ranging in age from 43 to 86, participated in a baseline examination and were examined at 5-year intervals over a 20-year period.  Participants were asked at subsequent examinations if they had regularly used aspirin at least twice a week for more than 3 months. Over the course of their study, there were 512 cases of early AMD and 117 cases of late AMD. The researchers found regular aspirin use for 10 years prior to retinal examination had an estimated incidence of late AMD of 1.76% in regular aspirin users and 1.03% in nonusers. Neovascular AMD had a significant association with aspirin use: 1.4% of aspirin users had neovascular AMD compared with 0.6% for non-aspirin users. There was no significant association for early AMD with aspirin use.

Then a study published online January 21 from JAMA Internal Medicine reported that patients who reported using aspirin at least once a week were twice as likely as nonusers to develop neovascular AMD over a 15-year study period.³ This study tracked 2389 people whose aspirin intake and vision loss were tracked through 4 examinations over a 15-year period. The cumulative incidence of wet AMD in the regular aspirin users was 9.3 percent over the 15-year period of the study vs 3.7 percent in non-aspirin users.

So, is this something to worry about clinically? Let’s not change our clinical practice just yet.

“I just don’t see it in my practice,” said Dr. Alex Talalight, a retinal specialist in Huntsville, AL. “Plus, there is no obvious mechanism for how aspirin can produce this effect. So, if my patient is on a daily aspirin therapy prescribed by her physician or cardiologist for secondary prevention of heart attack or stroke, then the benefits of the aspirin therapy clearly outweigh the risk of AMD. For those patients taking aspirin long-term for pain control, I might be careful in that group.”

Back to my patient. How did I respond to her question?

“No, ma’am,” I said. “I don’t think you got to worry about the aspirin making you go blind. I’d be more worried about what would happen to you if you stopped the aspirin. But I would discuss it with your medical doctor if you’re concerned. If you want to stop something, how about those cancer sticks?”

She grinned. “Ah heck, Ernie, we all got to go somehow.”

References

1.  Mayo Clinic staff. Daily aspirin therapy: Understand the benefits and risks. Mayo Clinic website. Available at: http://www.mayoclinic.com/health/daily-aspirin-therapy/HB00073. Accessed January 30, 2013.

2.  Klein BA, Howard  KP, Gangnon RE, et al. Long-term use of aspirin and age-related macular degeneration. JAMA 2012; 308 (23): 2469-2478.

3.  Liew G, Mitchell P, Wong TY, et al.  The association of aspirin use with age-related macular degeneration. JAMA Intern Med 2013. Available at: http://archinte.jamanetwork.com/article.aspx?articleid=1558450. Accessed January 29, 2013