In a large case-control study using a national database of patients, metformin use was associated with reduced odds of developing age-related macular degeneration (AMD). This association was dose dependent, with the greatest benefit at low to moderate doses. When looking only at patients with diabetes, the authors note preservation of the dose-dependent decrease in the odds of patients developing AMD. Metformin does not appear to be protective in patients with diabetes and coexisting diabetic retinopathy. This study suggests that metformin may be useful as a preventive therapy for AMD and provides the basis for potential prospective clinical trials.
