Abstract
Purpose :
To investigate if metformin use is associated with reduced odds of developing new dry AMD.
Methods :
This was a retrospective case-control study. 194,135 subjects with new diagnoses of dry AMD from 01/2008 to 12/2017 and 193,990 matched controls were identified using the Merative™ MarketScan® Research Databases. 49,988 cases and 49,460 controls were included in the diabetic subgroup. Associations between the development of dry AMD and metformin use were analyzed, as well as two-year cumulative doses of metformin categorized by quartile: 1-270g, 271-600g, 601-1080g, and >1080g. These regressions were repeated in the subset of cases and controls with diabetes as well as in diabetic subjects with and without diabetic retinopathy (DR). Multivariate logistic regression analyzed the association between the development of dry AMD and the combination of metformin with other medications compared to metformin alone. Every regression was stratified by year, age group, hypertension, anemia, region, and CCI group.
Results :
In multivariate logistic regression, any metformin use was associated with reduced odds of developing dry AMD (OR 0.97, CI 0.95-0.99)and for cumulative two-year doses from 1-270g and 271-600g (1-270g: OR 0.93, CI 0.90-0.97; 271-600g: OR 0.92; CI 0.89-0.96). In the diabetic subgroup, metformin exposure below 601g/2y reduced the odds of developing dry AMD (1-270g: OR 0.93, CI 0.90-0.97; 271-600g: OR 0.92; CI 0.89-0.96). In diabetic patients without DR, the odds of developing dry AMD were reduced by any metformin use (OR 0.97, CI 0.94-0.998) and doses from 1-270g (OR 0.96, CI 0.91-0.998) and 271-600g (OR 0.92, CI 0.88-0.96) but was not reduced in patients with DR. Finally, sulfonylureas or statins in combination with metformin decreased the odds of developing dry AMD compared to metformin alone (sulfonylureas: OR 0.90, CI 0.87-0.94; statins: OR 0.96, CI 0.91-0.998).
Conclusions :
In a large sample size, metformin use was associated with reduced odds of developing dry AMD both in the full cohort and also in the diabetic cohort. Metformin may represent a preventive strategy for dry AMD, and these data may guide future clinical studies.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.