BACKGROUND: Proliferative vitreoretinopathy (PVR) is partially caused by peptide growth factors, stimulating the cell by binding to a transmembrane tyrosine kinase receptor. We studied the effects of herbimycin A (HA), a tyrosine kinase inhibitor, in PVR. METHODS: Toxicity studies: Electroretinography and histological studies were performed after intravitreal injection of HA. Efficacy studies: Homologous rabbit dermal fibroblasts were injected intravitreally, followed by injection of HA. The presence of tractional retinal detachment (TRD) and severity of inflammation were assessed. RESULTS: Toxicity studies: Eyes injected with HA exhibited decrease in B-wave amplitude initially, with subsequent recovery. Histologically, damage to photoreceptors was evident after injection of high but not of low doses of HA. Efficacy studies: Inflammatory response and the development of TRD were significantly reduced with all doses of HA. CONCLUSIONS: HA (20 microM) was found to be effective and safe in preventing the development of inflammation and TRD.
BACKGROUND:Proliferative vitreoretinopathy (PVR) is partially caused by peptide growth factors, stimulating the cell by binding to a transmembrane tyrosine kinase receptor. We studied the effects of herbimycin A (HA), a tyrosine kinase inhibitor, in PVR. METHODS:Toxicity studies: Electroretinography and histological studies were performed after intravitreal injection of HA. Efficacy studies: Homologous rabbit dermal fibroblasts were injected intravitreally, followed by injection of HA. The presence of tractional retinal detachment (TRD) and severity of inflammation were assessed. RESULTS:Toxicity studies: Eyes injected with HA exhibited decrease in B-wave amplitude initially, with subsequent recovery. Histologically, damage to photoreceptors was evident after injection of high but not of low doses of HA. Efficacy studies: Inflammatory response and the development of TRD were significantly reduced with all doses of HA. CONCLUSIONS: HA (20 microM) was found to be effective and safe in preventing the development of inflammation and TRD.