Clinical and morphological features of cells implicated in the pathogenesis of idiopathic epiretinal membrane formation in patients with different visual acuity

Among various cellular populations, ERMs contain cells with contractile features typical of myofibroblasts. This type of cells provides collagen producing and facilitates membrane contraction. The identification of ERM morphological elements at different stages of its formation remains a topical question.Purpose. To investigate the cells morphological features in a qualitative composition of epiretinal membranes in patients with different visual acuity.Material and methods. All patients were divided into 3 equal groups of 20 patients (20 eyes), depending on the initial best corrected visual acuity (BCVA). Samples of ERM were obtained from 60 patients during microsurgical operations with subseuqent. There was performed an immunohistochemistry to recognize: glial acidic fibrillary protein (GFAP), TGF-β1, α-SMA actin, cellular retinaldehyde-binding protein (CRALBP), fibronectin, CD68, CD45, aswell as collagen of II, IV, VI types.Results. Specimens, removed from eyes with a higher visual acuity, showed a more cell viability than specimens, removed from eyes with a lower visual acuity. Comparing these specimens we found significant differences in cell viability depended on cell proliferation and transdifferentiation. Our results revealed that ERMs are characterized by the intensive decreasing of glial acidic fibrillary protein (GFAP) expression and competitive increasing α-SMA actin myofibroblast-like cells in time. As a result, we detected a diffuse presence of α-SM actin–positive myofibroblasts containing TGF-β1 and collagen expression at late stages. Conclusion. Immunocytochemical analysis helps to identify the pathomorphological changes of ERM samples and to determine mechanisms of ERM formation in patients with a different severity of pathological process.