Introduction  Idiopathic epiretinal membrane (ERM) is an avascular fibrocellular membrane that proliferates at the vitroretinal junction. The membrane contains cells and extracellular matrix (ECM). The cellular components include: RPE cells, myofibroblast/fibroblast and glial cells etc. The formation of ERM is a fibrosis process, which many ECM proteins are involved, including: fibronectin, laminin and collagens. The migration, proliferation and differentiation of cells and other cellular functions are influenced by ECM. Little is known about the collagens in this process. Collagen VI has been shown to be involved in liver and lung fibrosis and the transdifferentiation of fibroblast to myofibroblast. Collagen VI has been identified in normal vitreous and ILM as well as in ARMD and FTMH. But the presence of type VI collagen in ERM has not yet been documented. We hypothesize that the anchoring and cell signaling effect of collagen VI may have an important role in ERM formation.
Purpose  The purpose of the study was to investigate the distribution of type VI collagen in idiopathic epiretinal membranes (ERM) and the possible relationship between type VI collagen and the pathogenesis of gliosis around the macular area with a bird's-eye-analysis.
Methods  ILMs with pre-retinal membranes obtained from surgeries were flat-mounted and subjected to immunohistochemistry using antibodies against type VI collagen and Glial Fibrillary Acidic Protein (GFAP, glial cell marker) and imaged with a confocal laser scanning microscope (CLSM) to gain a comprehensive overview of the membranes.
Results  Pre-retinal membranes appeared as type VI collagen-positive microfibril networks attached to the ILM. Multiple cells, some of which were GFAP-positive glial cells, were seen on its surface. Glial cells sometimes showed type VI collagen within their cytoplasm.  
Conclusion  Pre-retinal membranes appeared as type VI collagen-positive microfibril networks attached to the ILM. Multiple cells, some of which were GFAP-positive glial cells, were seen on its surface. Glial cells sometimes showed type VI collagen within their cytoplasm.