Diabetes drug could treat leading cause of blindness

University of Texas Medical Branch at Galveston researchers have discovered that a drug already prescribed to millions of people with diabetes could also have another important use: treating one of the world's leading causes of blindness.

In laboratory rat and cell-culture experiments, the scientists found that , which is commonly used to control in , also substantially reduced the effects of , an of the tissues just below the outer surface of the . Uveitis causes 10 to 15 percent of all cases of blindness in the United States, and is responsible for an even higher proportion of blindness globally. The only treatment now available for the disorder is steroid therapy, which has serious side effects and cannot be used long-term.

"Uveitis has various causes — the most common are infectious diseases and autoimmune disorders— but they all produce inflammation within the eye," said UTMB professor Kota V. Ramana, senior author of a paper on the study now online in the journal Investigative Ophthalmology & Visual Science. "Metformin inhibits the process that causes that inflammation."

The scientists discovered metformin's efficacy when they tested it in rats given an endotoxin that mimicked the inflammatory effects of bacterial infection. The results showed clearly that metformin was a very effective anti-uveitis agent.

"We found that the drug is therapeutic as well as preventive — if we gave our rats the drug beforehand, they didn't develop uveitis, and if we gave it after uveitis had developed, it was therapeutic," said UTMB professor Satish Srivastava, also an author of the IOVS paper. "Metformin's strong anti-inflammatory properties make this possible."

According to the researchers, metformin works by activating an enzyme called AMPK, which in turn damps down the activity of the protein NF-kappa B. The inhibition of NF-kappa B suppresses the production of inflammatory signaling molecules — cytokines and chemokines — needed to initiate and sustain uveitis.

Because metformin is already used so widely as a therapy for diabetes, the UTMB scientists believe that it has a good chance of being rapidly adopted as an anti-uveitis drug.

"I think after a few more pre-clinical studies are done, we can get this drug to patients in a shorter time than usual," Ramana said. "Its safety is already known, so all that we need to see is its efficacy in humans."

Related Stories

Melatonin may save eyesight in inflammatory disease

Nov 23, 2008

Current research suggests that melatonin therapy may help treat uveitis, a common inflammatory eye disease. The related report by Sande et al., "Therapeutic Effect of Melatonin in Experimental Uveitis," appears in the December ...

Recommended for you

HIV/AIDS drugs could be repurposed to treat AMD

Nov 20, 2014

A landmark study published today in the journal Science by an international group of scientists, led by the laboratory of Dr. Jayakrishna Ambati, professor & vice chair of the Department of Ophthalmology & Visu ...

New laser therapy helps slow macular degeneration

Nov 19, 2014

(Medical Xpress)—A new, low impact low energy laser treatment for patients with early age-related macular degeneration (AMD) has produced positive results by reducing indicators of the disease.

User comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.