RETINOIC ACID IN SILICONE AND SILICONE-FLUOROSILICONE COPOLYMER OILS IN A RABBIT MODEL OF PROLIFERATIVE VITREORETINOPATHY

Purpose. The authors evaluated the effect of retinoic acid (RA) in sil icone oil (SiO) and in silicone-fluorosilicone (SiFO) copolymer oil in a new rabbit model of proliferative vitreoretinopathy (PVR). Methods. To create the PVR model, three groups of rabbits were administered vi treous injections of approximately 100,000 homologous fibroblasts, 75, 000 platelet-rich plasma (PRP), and fibroblasts + PRP, respectively. T hese rabbits were followed up ophthalmoscopically and histopathologica lly for as long as 2 months. Five additional groups of rabbits underwe nt gas-compression vitrectomy in one eye. Four days later, group 1 was administered intravitreous RA in SiFO (9 mu g/ml) with approximately 150,000 fibroblasts and 70,000 PRP. Group 3 was administered the same amount of fibroblasts and PRP as group 1 with RA in SiO (9 mu g/ml). G roups 2, 4, and 5 were administered the same amount of fibroblasts and PRP as groups 1 and 3 with 1 ml of SiFO, SiO, or balanced salt soluti on only, respectively. To evaluate RA toxicity, RA was injected in SiO (15 and 20 mu g/ml) and RA in SiFO (10 mu g/ml). Results, All eyes th at were administered fibroblasts or PRP developed vitreous membranes, but those with PRP alone did not develop proliferative changes or reti nal detachment; fibro blasts alone produced proliferative changes and retinal detachment after 2 to 3 weeks; fibro blasts + PRP produced sim ilar changes within 3 days of injection. Retinoic acid (15 mu g/ml) in SiO and RA (10 mu g/ml) in SiFO was well tolerated, Retinal atrophic changes were found in eyes with 20 mu g/ml RA in SiO, The retinal deta chment rate was lower (P < 0.05) in the eyes that were administered fi broblasts + PRP and RA than in the controls. Significant differences w ere found in the degrees of PVR among the groups. Conclusions. RA coul d be useful in PVR treated with SiO or for eyes treated intraoperative ly with heavier-than-water SiFO when it is used as a short-term retina l tamponade.