Liposome-encapsulated 5-fluorouracil in the Treatment of Proliferative Vitreoretinopathy

Liposomes, small bilayer vesicles composed of phospholipids, can entrap and thus slow the release of drugs. We investigated the use of liposome-encapsulated 5-fluorouracil (5-FU), an antiproliferative agent, in the treatment of proliferative vitreoretinopathy (PVR) in an animal model. Doses of up to 1.6 mg administered intravitreally in rabbits demonstrated no retinal toxicity by histologic or electroretinographic criteria. In an experimental animal model of PVR, intravitreal injection of homologous rabbit corneal fibroblasts caused tractional retinal detachments in 90% of eyes after 4 weeks. The addition of 1.6 mg of liposome-encapsulated 5-FU decreased the rate of detachment to 32%, compared with 55% for 1 mg of free 5-FU. Thus, liposomal encapsulation of an anti-proliferative agent such as 5-FU may be a valuable adjunct to conventional vitreous surgery in managing PVR.