Cell composition and immunohistochemical detection of VEGF, TGF-beta, and TNF-alpha in proliferative vitreoretinopathy.

Formation of vascularized membranes inside the vitreous leads to retinal detachment and blindness. In this paper it is shown that vitreal membranes are composed of newly formed vessels and myofibroblasts, immersed in a loose stroma with sparse histocytes. Vascular endothelial growth factor (VEGF) is clearly present in cellular constituents of the membranes and, therefore, represents a fundamental cytokine in their formation, while transforming growth factor-beta (TGF-beta) and tumor necrosis factor-alpha (TNF-alpha) are not. Considering that the composition of vitreal membranes clearly resembles scar tissue, the absence of TGF-beta in the membranes could explain their peculiar histological appearance.