Prevention of experimental proliferative vitreoretinopathy with a biodegradable intravitreal drug delivery system of all-trans retinoic acid.

Abstract

To evaluate the antiproliferative effect of an all-trans retinoic acid (at-RA) drug delivery system (DDS) on experimental proliferative vitreoretinopathy (PVR). PVR was induced in rabbits with core vitrectomy and fibroblast injection. The DDS containing 420 microg, 650 microg, and 1,070 microg of at-RA was implanted into the vitreous of treated groups B, C, and D, respectively. Group A with no DDS and group E with nonmedicated DDS served as controls. The intravitreal at-RA concentration was measured with high-pressure liquid chromatography. The drug toxicity was evaluated histologically. The severity of PVR was significantly reduced in groups C and D but not in groups A, B, and E. The drug release peaked at 6 weeks to 7 weeks. No signs of retinal toxicity were found in the DDS groups. Intravitreal implantation of at-RA DDS appears effective in inhibiting the development of PVR and is well tolerated in rabbit eyes.