An experimental drug may help some people with diabetes avoid vision loss.

The drug, from Eli Lilly, is still going by its generic name, ruboxistaurin or RBX. It's being tested in a large-scale clinical trial.

Results of a smaller trial, reported in the July issue of Diabetes, bring both good and bad news. The study looked at 252 people with severe nonproliferative diabetic retinopathy. That happens when tiny blood vessels in the retina -- the eye's projection screen -- become damaged and leaky, causing small hemorrhages, swelling, and scarring of the retina.

Nonproliferative diabetic retinopathy sounds bad. Many people with diabetes have mild forms of the disease that don't affect vision; however, if left untreated it can lead to blindness.

That bad news from the study is that RBX had no effect on the progression of eye disease.

The good news is that over three to four years of treatment, the drug seems to cut a person's risk from diabetic macular edema. That's when leaking blood vessels make the middle part of the retina swell, affecting vision. It can greatly reduce a person's sharp, central vision.

That's a very positive finding, says researcher Lloyd Paul Aiello, MD, PhD, director of Joslin Diabetes Center's Beetham Eye Institute in Boston.

"RBX may eventually offer a new treatment option for patients with diabetes, especially in light of the lack of serious side effects reported to date," Aiello says in a news release.

Eli Lilly funded the study. Lilly is a WebMD sponsor.

Read WebMD's "Get the Facts about Diabetes"

By Daniel J. DeNoon, reviewed by Brunilda Nazario, MD

SOURCES: Aiello, L.P. Diabetes, July 2005; vol 54: pp 2188-2197. News release, Joslin Diabetes Center.