Does metformin use protect against the development of AMD?

Posted on

The use of the antidiabetic drug metformin was associated with reduced odds of developing age-related macular degeneration (AMD), according to data from a large case-control study published in JAMA Ophthalmology. The greatest benefit was seen in patients on low to moderate doses.

This study included 312,404 patients aged >55 years with newly diagnosed AMD and 312,376 matched control participants. A total of 26% and 25.5% of patients had diabetes in the case and control groups, respectively.

Metformin use was associated with reduced odds of developing AMD (odds ratio [OR], 0.94 [95% CI, 0.92-0.96]); the association was dose dependent, with the greatest potential benefit found in patients on low to moderate doses. (dosages over 2 years: 1-270 g, OR, 0.91 [95% CI, 0.88-0.94]; 271-600 g, OR, 0.90 [95% CI, 0.87-0.93]; 601-1080 g, OR, 0.95 [95% CI, 0.92-0.98]).

There were no reduced odds of developing AMD in doses of >1080 g of metformin over 2 years.

In a cohort of only patients with diabetes, the reduction in odds ratio and the dose-dependent response were preserved. In patients with diabetes, the use of metformin was associated with a decreased OR of AMD, but it was a risk factor in patients with diabetic retinopathy (OR, 1.07 [95% CI, 1.01-1.15]). The authors concluded that “metformin may be useful as a preventive therapy for AMD and provides the basis for potential prospective clinical trials.”

Blitzer AL, Ham SA, Colby KA, et al. Association of metformin use with age-related macular degeneration: A case-control study. JAMA Ophthalmol. 2021; doi:10.1001/jamaophthalmol.2020.6331

Related Articles
Wearable collision warning device helps visually impaired individuals
Jul 22, 2021
Psoriasis linked with significantly higher risk of retinal diseases
Jul 20, 2021
Ranibizumab biosimilar has comparable efficacy, safety profile to reference product in patients with nAMD
Jul 19, 2021