Epiretinal Membrane of Proliferative Diabetic Retinopathy: An Immunohistochemical Study

Abstract

Nineteen cases of epiretinal membrane (ERM) in proliferative diabetic retinopathy were studied using immunohistochemical methods. Antibodies against type I-IV collagen, fibronectin (FN), glial fibrillary acidic protein (GFAP), vimentin and the monoclonal antibody (MAB) against human Müller cells were used to examine the membranes. Type II collagen was found on one side of the ERMs in 95% of the cases. The other types of collagen, FN and vimentin were also identified in most cases. Müller cells (GFAP- and MAB-positive) were found in 2/19 cases (11 %), and astrocytes (GFAP-positive but MAB-negative) were found in 10/19 cases (53%). These results suggest that type II collagen (vitreal collagen) may act as a scaffolding in the formation of ERMs and that glial elements of the ERMs consist mainly of astrocytes.

Glial cell involvement in vascular occlusion of diabetic retinopathy

“…The retinal glial cells have a multitude of roles for retinal maintenance and function, ranging from involvement in retinal metabolism (Newman 1987), endocrine functions (Berka et al 1995), and importance for the structural development of the retina (Tout et al 1993). Furthermore, retinal glial cells proliferate in response to retinal injury in general as well as to specific mitogens (Puro et al 1990), and these cells are strongly involved in the formation of epiretinal membranes in proliferative vitreoretinopathy (Nork et al 1987;Hosoda et al 1993). Future studies will show whether the present finding of glial cell invasion into retinal vessels can point towards new experimental approaches for elucidating the pathophysiology of retinal disease, notably vascular occlusion in diabetic retinopathy.…”

The pathogenesis of diabetic retinopathy: old concepts and new questions

“…103 Animal models also show that retinal expression of collagen type IV and fibronectin increases in hyperglycaemic rats. [104][105][106] Diabetic basement membrane thickening appears to involve qualitative alterations of specific basement membrane markers at an advanced disease stage, with the appearance of diabetic retinopathy. For instance, abnormal accumulation of several extracellular matrix components in retinal basement membranes may trigger the deposition of small tenascin-C isoforms in the blood vessel walls.…”

The Interaction between the Renin-Angiotensin System and Vascular Endothelial Growth Factor in the Pathogenesis of Retinal Neovascularization in Diabetes

“…Retinal Müller cells have been identified as a component of diabetic epiretinal membranes [40, 41]and have been shown to induce endothelial cells to form blood-brain barrier properties in the rat eye [42]. Müller cells are macroglial cells whose endfeet provide a basement membrane that fuses with the basement membrane of smooth muscle cells, pericytes and endothelial cells of retinal blood vessel walls [42].…”