INHIBITION OF EXPERIMENTAL PROLIFERATIVE VITREORETINOPATHY IN RABBITS BY SURAMIN

Proliferative vitreoretinopathy (PVR) is the most common cause for failure of retinal reattachment surgery. In a search for better pharmacologic treatment of PVR, we investigated the effect of intravenous injections of suramin on an experimental rabbit model of PVR. PVR was induced in rabbits by intravitreal injection of autologous fibroblasts. The experimental group (7 eyes) received intravenous injections of suramin (100 mg/kg body weight) every 3 days for 15 days, beginning 3 days before fibroblast injection. The control group (5 eyes) was treated similarly but received intravenous saline solution in place of suramin. A third group (4 eyes) received suramin according to the protocol above but did not receive intravitreal fibroblasts. The animals were examined by indirect ophthalmoscopy every 3 days and were sacrificed 14 days after the injection of fibroblasts. The serum levels of suramin were evaluated by high-performance liquid chromatography. The PVR was classified as stages I-V, based upon clinical findings. PVR developed in both experimental and control animals but was less severe in those treated with suramin. On day 14, the average stage of PVR in the control group was 3.8; in the suramin-treated group, however, the average stage was 2.4, which was significantly less than in the control group (p<0.02). None of the rabbits in the third group showed pathologic changes. Serum levels of-suramin were maintained at an average of 280.2 mu g/ml and no apparent toxicity was found in the retina by histologic study. These results suggest that suramin has an inhibitory effect on PVR in a rabbit model and may have the potential as a pharmacologic modulator of PVR in humans.