Patients taking acetylcholinesterase inhibitors for Alzheimer’s disease may have a reduction in the risk of developing age-related macular degeneration (AMD), according to research at University of South Carolina.
The researchers acted on the hypothesis that AMD results partly from inflammatory reactions in the macula. Because acetylcholinesterase inhibitors have anti-inflammatory effects, they wanted to determine if these drugs reduce the risk of AMD in patients with Alzheimer’s disease.
To do so, they investigated the association between acetylcholinesterase inhibitors and the incidence of AMD in a propensity score–matched retrospective cohort study.
Patients who were in health care facilities in the US Department of Veterans Affairs (VA) health care system were included from January 2000 through September 2023. All participants were aged 55 to 80 years and received a diagnosis of Alzheimer’s disease during those ages; in addition, none had a preexisting diagnosis of AMD in the VA database.
All included patients had been treated with acetylcholinesterase inhibitors for Alzheimer’s disease. The study’s main outcome measure was the first diagnosis of AMD.
The investigators reported that 21,823 veterans with Alzheimer’s disease were identified and included in the study. The mean patient age was 72.3 years. The vast majority, 97.7% were men.
The analysis showed that propensity score–matched Cox model reveals each additional year of acetylcholinesterase inhibitors treatment was associated with a 6% lower hazard of AMD (hazard ratio, 0.94; 95% confidence interval, 0.89-0.99).
The data indicated that patients with Alzheimer’s disease who were treated with acetylcholinesterase inhibitors had a slightly lower hazard of developing AMD compared with untreated patients. In contrast, the use of memantine, another treatment for Alzheimer’s disease, was not found to be associated with the incidence of AMD in this study.
The investigators conclude that this observational study reports a small reduction in the risk of AMD among veterans with Alzheimer’s disease receiving acetylcholinesterase inhibitors. Randomized clinical trials would be needed to determine if there is a cause-and-effect relationship and further research is required to validate these findings across diverse populations.