Morphological Patterns of Diabetic Neovascular Membranes

Abstract

Abstract: : Purpose: this study was undertaken to identify the presence of typical morphological patterns in diabetic neovascular membranes (DNM), obtained from patients who required vitreoretinal surgery. Methods: 47 neovascular membranes were examined from patients with proliferative diabetic retinopathy with or without retinal detachment and with or without vitreous hemorrhage. In all cases, a three port pars plana vitrectomy was undergone to remove the membranes. Neovascular tissues were studied with hematoxylin and eosin, PAS and Masson trichrome. Immunohistochemistry was performed in each case using antibodies to the following antigens: vimentin, protein S–100, glio–fibrilar acid protein, pan B, pan T, factor VIII and CD 68. Results: 3 types of DNM were found: – membranous: flat membrane with internal vascular growth with a 100–200 µm or extensive horizontal growth. – dendritiform: collagen membrane with neovessels 50–300 µm – glomerular: predominantly collagen membrane with neovascular ingrowth into the vitreous, and – mixed Conclusions: a new morphological classification of DNM is presented. Prognostic vascular patterns and clinical correlation can be identified in each group.

Keywords: diabetic retinopathy • pathology: human • retinal neovascularization