Common Diabetes Rx Might Be a Sight-Saver

Metformin may prevent open-angle glaucoma in diabetes patients

/ Author:  / Reviewed by: Joseph V. Madia, MD Beth Bolt, RPh

(RxWiki News) It’s always nice to get a clear view. One diabetes medication may help patients do just that.

A new study found that diabetes patients who took metformin had a lower risk of developing open-angle glaucoma.

"Should these findings be confirmed in other populations in prospective clinical trials, they may lead to novel treatments for this sight-threatening disease and offer new opportunities to reduce other risks of aging," wrote lead study author Julia E. Richards, PhD, of the University of Michigan, Ann Arbor, and colleagues.

Dr. Richards and team looked at patients with diabetes who took metformin (brand names Glumetza, Fortamet, Glucophage and Riomet).

Open-angle glaucoma (OAG) is one of several types of glaucoma. In glaucoma, pressure inside the eye increases because fluid doesn't drain from the eye. This eventually impairs vision and may cause blindness. Glaucoma is usually painless.

Diabetes is a metabolic disease in which the body’s inability to produce any or enough insulin (a hormone made by the pancreas) causes blood glucose (blood sugar) levels to rise. Patients with diabetes often must take medications to help keep their blood sugar under control.

There are many possible complications of high blood sugar, including heart disease, nerve pain and vision problems. Glaucoma is not caused by diabetes. However, diabetes and glaucoma often coexist — especially in older patients.

Past research found that medications like metformin may help reduce the risk of diabetic complications — but this is the first study to look at age-associated eye diseases like glaucoma, according to researchers.

Dr. Richards and team looked at data on more than 150,000 diabetes patients. All patients received medical care between 2001 and 2010.

OAG was found to develop in almost 4 percent of these patients.

In addition to metformin, the patients were given common diabetes medications — such as sulfonylureas (brand name Glipizide), thiazolidinediones (brand name Pioglitazone), meglitinide (brand name Repaglinide) or insulin. Some patients were given more than one of these medications.

Dr. Richards and team found that patients who took metformin had a lower risk of OAG than those who did not. If a patient took the standard dose of 2 grams of metformin every day for two years, the risk of OAG dropped by almost 21 percent.

The risk of OAG did not change when patients took the other medications.

This study was published in the May issue of the journal JAMA Ophthalmology.

The National Eye Institute, a fellowship from the Heed Foundation and a grant from Research to Prevent Blindness funded this research.

No conflicts of interest were disclosed.

Review Date: 
May 27, 2015
Last Updated:
May 28, 2015