Vascular endothelial growth factor and fibroblast growth factor 5 are colocalized in vascular and avascular epiretinal membranes

PURPOSE: To determine by immunocytochemical analysis of epiretinal membranes whether vascular endothelial growth factor and the fibroblast growth factor FGF-5 are present in patients with proliferative diabetic retinopathy or proliferative vitreoretinopathy. METHODS: Human surgical specimens of epiretinal membranes were obtained from 11 eyes with proliferative diabetic retinopathy and five eyes with proliferative vitreoretinopathy. Sections were immunostained with an affinity-purified antibody against an internal sequence of human FGF-5 and with a commercially available affinity-purified antibody corresponding to the first 20 residues of human vascular endothelial growth factor. Slides were visualized using avidin-biotin-peroxidase complex. Control studies were performed with nonimmune immunoglobulin G and preabsorbed vascular endothelial growth factor and FGF-5 antibody, respectively. RESULTS: Immunoreactive FGF-5 is present in most cells, including endothelial cells of vascular and avascular epiretinal membranes, but seems to be absent from the extracellular matrix. A similar staining pattern was observed for vascular endothelial growth factor. CONCLUSIONS: Vascular endothelial growth factor and FGF-5 are remarkably colocalized in both vascular and avascular epiretinal membranes arising from proliferative diabetic retinopathy and proliferative vitreoretinopathy, respectively. This result questions the concept that the presence of a single angiogenic factor determines the vascular status of an epiretinal proliferation.