Association Between Metformin and Other Diabetic Medications and Five-year Onset of New Neovascular Age-related Macular Degeneration Diagnosis

BACKGROUND AND OBJECTIVE: Neovascular age-related macular degeneration (nAMD) is a sight-threatening condition with growing prevalence, but few therapies exist to prevent its development. This study investigates whether metformin reduces the odds of new nAMD diagnosis. PATIENTS AND METHODS: This was a case-control study using a nationwide insurance claims database of patients ages 55 and older with newly diagnosed nAMD from January 2008 to December 2019. Multivariable conditional logistic regression was utilized to determine how various exposures impacted the odds of new nAMD diagnosis. RESULTS: Among 55,080 cases with new nAMD diagnosis and 55,066 matched controls, any metformin exposure reduced 5-year odds of new nAMD diagnosis compared to individuals not on metformin (odds ratio [OR]: 0.94; 95% CI: 0.90 to 0.99). Insulin and sulfonylurea exposures were also protective. These findings were consistent in subgroup analyses of patients with diabetes without diabetic retinopathy. CONCLUSION: Metformin may reduce the 5-year odds of developing nAMD, particularly in diabetic patients without diabetic retinopathy.