Metformin May Reduce Open-Angle Glaucoma Risk

(HealthDay News) — Metformin is associated with a lower risk for developing open-angle glaucoma, according to a study published in JAMA Ophthalmology.

Julia Richards, PhD, a professor of ophthalmology and visual sciences at the University of Michigan in Ann Arbor, and colleagues collected 10 years of data on 150,016 people with diabetes. All were aged 40 years or older at the start of the study. 

During the study, the investigators found that 3.9% of the participants developed open-angle glaucoma.

Results revealed that patients taking the highest amount of metformin had a 25% reduced risk for developing open-angle glaucoma compared with those not taking the medication. For every 1-gram increase in metformin taken, the risk was reduced by 0.16%. 

The researchers estimated that taking a standard dose of metformin (2 grams per day) for 2 years would reduce the risk for open-angle glaucoma by 20.8%. This risk reduction was seen even after accounting for lower blood glucose levels, the study authors said. 

Other diabetes medications were not associated with reduced risk for open-angle glaucoma.

“This study suggests that metformin may be affecting [open-angle glaucoma] risk on multiple levels, some involving improved glycemic control and some involving mechanisms outside glycemic control such as neurogenesis, inflammatory systems, or longevity pathways targeted by caloric restriction mimetic drugs,” the researchers wrote. 

“If confirmed by prospective clinical trials, these findings could lead to novel treatments for this sight-threatening disease.”


  1. Lin H-C et al. JAMA Ophthalmol. 2015;doi:10.1001/jamaophthalmol.2015.1440.