Diabetes medications such as metformin and insulin were associated with a lower risk of open-angle glaucoma or AMD. Photo: Michael Chaglasian, OD, and National Eye Institute. Click image to enlarge.

Medications for diabetes demonstrate a protective effect against open-angle glaucoma and age-related macular degeneration (AMD), a study recently confirmed. While previous research suggested this, these studies hadn’t addressed confounding factors by indication. Using three Rotterdam Study (1990-2014) cohorts (n=11,260), researchers analyzed the association of diabetes medication use and common age-related eye diseases (open-angle glaucoma, AMD and cataract).

They reported that untreated type 2 diabetes was associated with a significantly higher risk of all three eye diseases, while the condition, when treated with metformin or other medication (insulin or sulfonylurea derivatives), was associated with a significantly lower risk of open-angle glaucoma or AMD, respectively.

Additionally, the cumulative lifetime risk for open-angle glaucoma was lower for individuals taking metformin than for individuals without type 2 diabetes. Individuals taking other medication also had a lower lifetime risk of AMD, the researchers reported. Diabetes medication wasn’t associated with cataract in the study, though diabetes itself was.

“Our findings accentuate the potential role of diabetes medication in the pathogenesis of open-angle glaucoma and AMD,” the researchers wrote. Based on these associations, they concluded that interventional clinical trials are warranted to confirm causality.

Vergroesen JE, Thee EF, Ahmadizar F, et al. Association of diabetes medication with open-angle glaucoma, age-related macular degeneration, and cataract in the Rotterdam Study. JAMA Ophthalmol. May 19, 2022. [Epub ahead of print].