SILICONE OIL AS A DELIVERY VEHICLE FOR BCNU IN RABBIT PROLIFERATIVE VITREORETINOPATHY

The antiproliferative properties of a single intravitreous injection o f BCNU [carmustine; 1,3-bis(2 chloroethyl)-1-nitrosourea] dissolved in 1 ml of medical grade, 1,000-centistoke silicone oil were evaluated i n a rabbit model of proliferative vitreoretinopathy (PVR). 10 mug and 15 mug of BCNU in 1 ml silicone oil resulted in a 46% and 27% reductio n in the incidence of retinal detachments, respectively. Chi-square te sts showed a significant statistical difference (P < 0.05) between the control and treated groups. However, histopathologic examination of t he eyes injected with BCNU and silicone oil indicated some retinal dis organization even at the lower therapeutic levels. With a therapeutic index of <1.0, BCNU in silicone oil has a low margin of safety for tre atment of PVR. Nevertheless, this study demonstrates that silicone oil when used for retinal tamponade in PVR may be the vehicle for deliver y of a lipophilic antiproliferative agent.