13-CIS-RETINOIC ACID IN SILICONE-FLUOROSILICONE COPOLYMER OIL IN A RABBIT MODEL OF PROLIFERATIVE VITREORETINOPATHY

The purpose of this study was to evaluate the effect of 13-cis-Retinoi c Acid (RA) in Silicone-Fluorosilicone Copolymer Oil (SiFO) in a rabbi t model of proliferative vitreoretinopathy (PVR). Rabbits underwent ga s-compression vitrectomy. During gas-SiFO exchange, group 1 was inject ed with 1 mi (10 mu g ml(-1)) 13-cis-RA in SiFO, group 2 with 1.5 ml(9 mu g 1.5 ml(-1)) all-trans-RA in SiFO, group 3 with 1 mi SiFO alone, and group 4 with balanced salt solution (BSS). Groups 1-4 were also in jected with 0.1 mi suspension of fibroblasts (75,000 0.1 ml(-1)) and 0 .05 mi platelet rich plasma (70,000 0.1 ml(-1)), and were observed for 4 weeks. Group 5 was injected with SiFO alone, group 6 with 1 mi (10 mu g ml(-1)) 13-cis-RA in SiFO, group 7 with 1.5 mi (9 mu g 1.5 ml(-1) ) all-trans-RA in SiFO, and group 8 with BSS. After 4 weeks, groups 5- 7 underwent SiFO-BSS exchange. ERG and histopathology were performed t o test for retinal toxicity in groups 5-8. The incidence of traction r etinal detachment at 4 weeks was: group 1, 42.9%; group 2, 36.4%; grou p 3, 87.5%; and group 4, 88.9%. A significant difference in the incide nce of PVR was noted between treated eyes (groups 1 and 2) and control eyes (groups 3 and 4) at 2, 3, and 4 weeks (P < 0.05). No significant difference in the incidence of PVR was found between groups 1 and 2 d uring the same observation periods. ERG and histopathological studies showed no differences between the treated and the control fellow eyes (group 5-7) after 4 weeks. 13-cis-RA in SiFO (10 mu g ml(-1)) is as ef fective as all-trans-RA in SiFO (9 mu g 15 ml(-1)) in controlling the incidence of PVR when used for short term retinal tamponade and does n ot appear to be associated with retinal toxicity. (C) 1997 Academic Pr ess Limited.