INTRAVITREAL SUSTAINED-RELEASE CORTICOSTEROID-5-FLUORURACIL CONJUGATEIN THE TREATMENT OF EXPERIMENTAL PROLIFERATIVE VITREORETINOPATHY

Purpose. Proliferative vitreoretinopathy (PVR) remains the most common cause of failed retinal detachment (RD) surgery. The authors compared the effectiveness of two intraocular sustained-release codrugs in sup pressing PVR in a rabbit model: a surgically implantable pellet releas ing 5-fluorouracil (FU) and dexamethasone (DX) for 1 week and an injec table intravitreal sustained-release suspension releasing 5-FU and tri amcinolone acetonide for 1 month. Methods. Sustained-release devices a nd suspensions were prepared to deliver equimolar quantities of cortic osteroid and 5-FU. In group 1, devices were implanted surgically into the vitreous of the right eye of 10 New Zealand White rabbits. Ten con trol rabbits received surgical implantation of the suture only. In gro up 2, drug suspension was injected into the vitreous of the right eye of 10 New Zealand White rabbits. Ten control rabbits received injectio n of the vehicle only. One dq later, each rabbit was injected intravit really with 250,000 homologous rabbit dermal fibroblasts. Severity of PVR was graded clinically by two masked observers on days 3, 7, 10, 14 , 21, and 28. Results. In group 1, clinical severity of PVR was less i n the experimental group than in the control group at all time points; this was only statistically significant on day 10 (P = 0.04). Six eye s developed moderate to severe tractional RD or bullous RD in the cont rol group by day 10 compared with none in the experimental group (P = 0.01). In group 2, the median clinical grading of eyes in the experime ntal group was significantly less than that in the control group at al l time points through day 21 (P less than or equal to 0.01). Conclusio ns. Both the intravitreal sustained-release dexamethasone-5-FU device and the triamcinolone-5-FU suspension effectively inhibit the progress ion of PVR in a rabbit model. Simultaneous delivery of 5-FU and cortic osteroid may target different components of the wound-healing process in this disease.