Drugs for Dementia May Reduce Risk of Macular Degeneration
Using medications like donepezil (Aricept), known as acetylcholinesterase inhibitors (AChEIs), for treating dementia may potentially lower the risk of developing age-related macular degeneration (AMD), researchers suggest.
A study analyzing 9,642 patients between the ages of 55 and 80, who received medical services through the U.S. Veterans Affairs health system from 2000 to 2023, revealed a 6% reduced likelihood of AMD for each year of AChEI treatment (HR 0.94, 95% CI 0.89-0.99, P<0.001). The research, led by Joseph Magagnoli, MS, from the University of South Carolina in Columbia, indicated a correlation but not a definite cause-and-effect relationship, calling for further randomized clinical trials for confirmation.
AMD affects a substantial number of Americans, with an estimated 18.3 million individuals aged 40 and older experiencing early-stage AMD, and 1.49 million suffering from the late-stage version, which significantly impairs vision.
The study noted the ongoing debate regarding the possible link between Alzheimer’s disease and AMD, hypothesizing that both conditions could share common factors linked to the accumulation of beta-amyloid proteins.
Medication for Dementia May Mitigate Risk of Macular Degeneration.
The investigation into the role of AChEIs, typically used to slow cognitive decline, was initiated due to these potential associations. While these drugs have faced scrutiny for their limited efficacy, especially at higher doses, this study examined their potential benefits in reducing AMD risk.
The study followed 12,487 VA patients diagnosed with Alzheimer’s who were prescribed AChEIs like donepezil, rivastigmine (Exelon), and galantamine (Razadyne), along with 4,898 individuals taking a different dementia drug, memantine (Namenda). These groups were compared to a control group of 8,486 patients not on any dementia drugs.
Results showed a 4% lower rate of AMD among those using AChEIs compared to controls. This disparity increased to 6% per year when matched with patients not using dementia drugs. Notably, after about 17 years of AChEI use, a more pronounced difference in AMD rates was observed, suggesting a potential long-term effect.
The researchers highlighted potential mechanisms of action of AChEIs beyond their primary function, such as reducing inflammation and promoting vasoprotection. They also noted their association with various non-Alzheimer’s disease benefits, including lower risks of mortality, myocardial infarction, stroke, and slower progression of chronic kidney disease.
However, the study had limitations, including its retrospective nature, potential confounding factors, and focusing on a VA population, which may not fully represent the broader older population. The study also did not consider genetic factors or the adverse effects and costs associated with AChEIs, which have been reported in other research.
The findings suggest a potential link between AChEI use for dementia and reduced risk of AMD, but further research, including clinical trials, is necessary to establish a definitive relationship and understand its broader implications.