No significant association—protective or harmful—between commonly prescribed dementia medications, including memantine and donepezil, and the risk of developing age-related macular degeneration was found, according to a recent cohort study.

In the study, published in JAMA Network Open, investigators examined whether the dementia medications memantine and donepezil were associated with a reduced risk of age-related macular degeneration (AMD) in patients with dementia. AMD is a principal cause of blindness among participants aged 50 years or older and may share pathophysiological mechanisms with dementia. As a result of these potential shared mechanisms, the investigators assessed any associations between dementia treatments and AMD.

They included clinical data from 384,593 patients with dementia in the United Kingdom, divided into three cohorts: donepezil vs rivastigmine or galantamine; memantine vs donepezil, rivastigmine, or galantamine; and memantine vs rivastigmine or galantamine. After adjusting for confounders, no statistically significant association was observed between the dementia medications and AMD risk. Specifically, the adjusted hazard ratio (HR) for donepezil compared with rivastigmine or galantamine was 0.95 (95% confidence interval [CI] = 0.67–1.35). For memantine compared with other dementia drugs, the HRs were 1.03 (95% CI = 0.83–1.27) and 1.24 (95% CI = 0.83–1.86) in the respective cohorts.

The incidence of AMD was low across the groups, with crude rates of 3.8 per 1,000 person-years for donepezil users and 3.3 for those receiving rivastigmine or galantamine in cohort 1. In cohort 2, the incidence was 3.7 per 1,000 person-years for memantine users compared with 3.9 among the comparator dementia drug group. No statistically significant protective or harmful association was found between the dementia medications and AMD development. 

Full disclosures can be found in the published study.