Alzheimer's disease medications may protect against AMD

Older adults with Alzheimer's disease who are receiving treatment with acetylcholinesterase inhibitors (AChEIs) appears to have a small reduction in the risk of age-related macular degeneration (AMD), as reported in a study.

The study included 21,823 veterans with Alzheimer's disease (mean age 72.3 years, 97.7 percent men), among whom 12,847 were exposed to an AChEI, 4,898 patients were exposed to memantine, and 8,486 were untreated.  

Cox hazards regression analysis showed that every additional year of AChEI treatment conferred a 4-percent protection against AMD (hazard ratio [HR], 0.96; 95 percent confidence interval [CI], 0.93–0.99). Other factors that showed an association with AMD development included older age and being White or of other/unknown race versus being Black.

A propensity score–matched analysis that included 4,821 patients each in the AChEI-treated and untreated groups was also conducted. Compared with the AChEI group, the untreated group had a higher number of eye examination visits/clinic visits per year (median, 1.5 vs 1.32). Patients in the AChEI group consistently had lower cumulative AMD incidence over the follow-up period (p<0.001).

Multivariable Cox models showed results consistent with the initial analysis. Every additional year of AChEI treatment was associated with a 6-percent lower risk of AMD (HR, 0.94, 95 percent CI, 0.89–0.99). Factors associated with a higher risk of AMD were age (HR, 1.08, 95 percent CI, 1.06–1.09), White race (HR, 2.96, 95 percent CI, 2.13–4.10), and other/unknown race (HR, 2.84, 95 percent CI, 1.94–4.16).

Randomized clinical trials are warranted to establish a cause-and-effect relationship and validate the findings across diverse populations.