Antiproliferative effect of intravitreal alpha-tocopherol and alpha-tocopheryl-acid-succinate in a rabbit model of PVR

Abstract

Purpose: To evaluate the antiproliferative properties of alpha-tocopherol and alpha-tocopheryl-acid-succinate in a rabbit model of proliferative vitreoretinopathy.

Methods: Fifty-seven rabbits underwent gas-compression vitrectomy and gas/fluid exchange. Group 1 (n = 8): 50 micrograms alpha-tocopherol in 1 ml of 0.5% ethanol in balanced salt solution; Group 2 (n = 8): 50 micrograms alpha-tocopheryl-acid-succinate in 1 ml of 0.5% ethanol in balanced salt solution; Groups 3 (n = 4) and 4 (n = 2): 1 ml 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 ml silicone oil; Group 7 (n = 5): 1 ml balanced salt solution. Groups 1-3, and 5-7 also received fibroblasts and platelet-rich plasma injection. Fundus evaluation was performed during a four-week period. The eyes were enucleated for gross examination on day 28. Histopathology was performed on Group 4.

Results: Alpha-tocopherol and alpha-tocopheryl-acid-succinate in saline solution delayed development of proliferative vitreoretinopathy, compared to the control group (statistically significant during the first week, Mann Whitney, p < 0.05). The alpha-tocopherol in the silicone-oil group delayed development of proliferative vitreoretinopathy, compared to the silicone-oil group during the second to fourth weeks (no statistically significant difference, p > 0.05).

Conclusions: Alpha-tocopherol and alpha-tocopheryl-acid-succinate in saline solution showed retardation of proliferative vitreoretinopathy traction retinal detachments. In silicone oil, alpha-tocopherol is slowly released and decreases the severity of proliferative vitreoretinopathy, especially during the second week of follow-up.