RETINAL AND PRERETINAL LOCALIZATION OF EPIDERMAL GROWTH-FACTOR, TRANSFORMING GROWTH-FACTOR-ALPHA, AND THEIR RECEPTOR IN PROLIFERATIVE DIABETIC-RETINOPATHY

A number of growth factors have been implicated in the development and perpetuation of preretinal fibrovascular membranes in patients with p roliferative diabetic retinopathy (PDR). The aim of this study was to determine the potential role of epidermal growth factor (EGF), transfo rming growth factor alpha (TGF-alpha), and their receptor (EGF-R) in P DR development. Immunostaining for EGF, TGF-alpha, and EGF-R was compa red between normal retina, PDR retina, and PDR preretinal membranes. W eak staining for EGF and EGF-R was observed throughout the neural reti na from non-diabetic eyes while weak to moderate staining for TGF-alph a was observed in the ganglion cell layer and the inner and outer nucl ear layers. In contrast, intense staining for EGF and TGF-alpha and mo derate staining for EGF-R were observed throughout the PDR retina. Imm unoreactivity for EGF, TGF-alpha, and EGF-R was seen in the majority o f the 11 excised membranes studied and, though variable, was generally greater than that observed in normal retinas. These results suggest a n autocrine/paracrine role for EGF, TGF-alpha, and EGF-R in PDR.