Ophthalmic evolution was studied for 2 years in 17 patients with insulin-dependent diabetes mellitus and background diabetic retinopathy. Nine patients were treated with triflusal, a new platelet antiaggregant drug, and the eight remaining patients, with similar clinical and biological characteristics, were considered the control group. At the end of the study the ophthalmic evolution was different in the two groups. In the control group the degree of fluorescein leakage and the number of microaneurysms increased, while in the triflusal-treated group both parameters were reduced. There were no differences in visual acuity and computerised perimetry between the groups. Our results suggest that platelet antiaggregant therapy can be useful in the treatment of background diabetic retinopathy.