As part of that effort, Dr. Lorenzi of Harvard Medical School, Boston and colleagues compared the effects of the selective anti-platelet agent clopidogrel with that of aspirin in rats with streptozotocin-induced diabetes, and report the results in the December issue of Diabetes.

Aspirin at doses well below the anti-inflammatory range for humans prevented apoptosis of capillary cells and the development of acellular capillaries. Clopidogrel had no such effects and neither agent prevented early neuroglial abnormalities.

Use of the aldose reductase inhibitor sorbinil, which was employed as a benchmark for these agents' effects, prevented all abnormalities.

Such inhibitors are being tested for clinical safety and efficacy, say the investigators, and use of aspirin may provide an alternative or additional therapeutic strategy.

Dr. Lorenzi added that the 81 mg per day anti-platelet dose of aspirin "is already recommended to people with diabetes for prevention of cardiovascular disease when they have one additional risk factor."

"We hope," she concluded, "that patients will follow this official recommendation of the American Diabetes Association; it may have benefits that extend to the retinal vessels."