The effect of triamcinolone acetonide on a refined experimental model of proliferative vitreoretinopathy.

Animal models of proliferative vitreoretinopathy in which the intact vitreous body is injected with large numbers of fibroblasts do not resemble the human situation. Using a refined rabbit model of proliferative vitreoretinopathy in which the vitreous is compressed and partially detached from the retinal surface and small amounts of tissue-cultured homologous fibroblasts (25,000) are scattered over the vascularized part of the retina, we reevaluated the effect of intravitreally injected triamcinolone acetonide. We found that 2 mg of the corticosteroid reduced the incidence of retinal detachments from 90% to 56%. The effect was less than in previous models with intact vitreous. Large doses of the corticosteroid had no additional effect on the reduction of retinal detachments, indicating an optimal dosage of 2 mg. The effect of the corticosteroid on neovascularization was considerable; with 8 mg it could almost be prevented (reduction from 74% to 8%).