Washington ? A synthetic form of vitamin B1 that is used in Europe to treat nerve problems has been found to prevent the most common form of diabetes-related eye disease in rats.

Diabetic rats treated with benfotiamine for 36 weeks did not develop any of the retina damage found in a similar group of untreated rats, according to a research team led by Dr. Michael Brownlee of the Albert Einstein College of Medicine in New York.

Brownlee said he hopes to begin a clinical trial to determine whether a similar result would occur in humans once an effective dose for the drug in people is determined. That could happen as soon as a year, he said.

“We can’t say it works in humans because there has never been a double-blind clinical study” of it, Brownlee said.

The new findings are published today in the online edition of the journal Nature Medicine.

In the United States, diabetes is the leading cause of blindness in people age 20 to 70.

Diabetic retinopathy — damage to the small blood cells in the retina — is the most common problem. The American Diabetes Assn. estimates that between 12,000 and 24,000 people lose their sight each year because of diabetes.

In diabetics, excess sugar in the blood can damage some cells, especially those lining blood vessels, that are unable to block the sugar from entering. That sugar is burned for fuel by mitochondria, the energy engines of cells.

In cells that cannot regulate their amount of sugar, byproducts accumulate that can activate three different pathways of cell damage that can lead to blindness and other complications.