ANTIPROLIFERATIVE EFFECT OF INTRAVITREAL ALPHA-TOCOPHEROL AND ALPHA-TOCOPHERYL-ACID-SUCCINATE IN A RABBIT MODEL OF PVR

Purpose. To evaluate the antiproliferative properties of alpha-tocophe rol and alpha-tocopheryl-acid-succinate in a rabbit model of prolifera tive vitreoretinopathy. Methods. Fifty-seven rabbits underwent gas-com pression vitrectomy and gas/fluid exchange. Group 1 (n = 8): 50 mu g a lpha-tocopherol in 1 mi of 0.5% ethanol in balanced salt solution; Gro up 2 (n = 8): 50 mu g alpha-tocopheryl-acid-succinate in 1 mi of 0.5% ethanol in balanced salt solution; Groups 3 (n = 4) and 4 (n = 2): 1 m i 0.5% ethanol in balanced salt solution; Groups 5 (n = 12) and 8 (n = 9): alpha-tocopherol in 1 ml silicone oil(12 mg/ml) ; Group 6 (n = 9) : 1 mi silicone oil; Group 7 (n = 5): 1 mi balanced salt solution. Gro ups 1-3, and 5-7 also received fibroblasts and platelet-rich plasma in jection. Fundus evaluation was performed during a four-week period. Th e eyes were enucleated for gross examination on day 28. Histopathology was performed on Group 4. Results. Alpha-tocopherol and alpha-tocophe ryl-acid-succinate in saline solution delayed development of prolifera tive vitreoretinopathy, compared to the control group (statistically s ignificant during the first week, Mann Whitney, p < 0.05). The alpha-t ocopherol in the silicone-oil group delayed development of proliferati ve vitreoretinopathy, compared to the silicone-oil group during the se cond to fourth weeks (no statistically significant difference, p > 0.0 5). Conclusions. Alpha-tocopherol and alpha-tocopheryl-acid-succinate in saline solution showed retardation of proliferative vitreoretinopat hy traction retinal detachments. In silicone oil, alpha-tocopherol is slowly released and decreases the severity of proliferative vitreoreti nopathy, especially during the second week of follow-up.