Arxxant reduced the risk of vision loss in diabetics by nearly 41 percent, according to data from two Lilly-funded late-stage studies, which compared the experimental drug to a placebo. The three-year studies mainly focused on 813 patients, and found that declining vision occurred in 6.1 percent of patients taking Arxxant, also known as ruboxistaurin, compared to 10.2 percent in those taking placebo.

In this condition the vision loss cannot be corrected with the use of glasses, nor is it likely that any drug will restore the original vision, Arxxant medical director for Lilly said.

The findings that were announced at the American Diabetes Association's annual conference are important because retinopathy, or vision loss, affects 40 to 45 percent of all diabetics, according the National Institutes of Health. The potential patient pool is considerable because the ADA estimates that there are 20.8 million diabetics in America.

Diabetic retinopathy is a condition that leads to a progressive damage to the small blood vessels of the eye, and that can lead to vision loss and possible blindness. According to the World Health Organization and the American Diabetes Association estimates, DR is the leading cause of vision loss in adults of working age (20 to 65 years) in industrialized countries.