Diabetes drug metformin could protect against macular degeneration

A 13-year study of type 2 diabetes (T2D) patients has found metformin, one of the world’s highest-grossing anti-diabetic medications, could be protective against age-related macular degeneration (AMD), a leading cause of blindness in Americans older than 50.

The research, led by Yu-Yen Chen, MD, and presented at the American Academy of Ophthalmology’s annual congress in Chicago, studied tens of thousands of T2D patients enrolled in the Taiwan National Health Insurance Research Database. The team launched the study in an effort to detail the underlying etiology of AMD, which is still largely unknown.

What researchers do know, Chen said in a release, is that oxidative stress and inflammation play a critical role in the development and trajectory of AMD, which affects a part of the retina known as the macula. Scientists also know that metformin suppresses inflammation and oxidative stress, but the two concepts hadn’t been married prior to this study.

Chen et al. divided their study population into two groups: T2D patients who took metformin (45,524 patients) and those who didn’t (22,681 patients). After 13 years of follow-up, the researchers found that half as many patients in the metformin cohort had AMD compared to the control group.

“Our study is the first to reveal the protective effect of metformin on the development of AMD,” Chen said. “While more study is required to determine just how metformin protects against the development of AMD, this is an exciting development for patients at risk.”