Histological Study Of Macular Membrane And Internal Limiting Membrane Of Idiopathic Macular Membrane

Objective:The purpose of this study was to compare the features of ILM and epiretinal membranes covering macular of primary and secondary etiology and to further elucidate the pathogenesis of macular hole and membrane formation.Methods:Twenty epiretinal membranes or ILM associated with IMH (stages Ⅱ-Ⅳ), macular membrane were harvested during pars plana vitrectomy after removal of the posterior vitreous.Four membranes were derived from eyes with idiopathic macular membrane, seven from IMH, nine from secondary macular membrane.Then we examined them light and electron microscopically.Results:1All twenty specimens contained a continuous undulating piece of membrane.But ELM and macular membrane have different lookings,ILM has a even smooth and transparent texture,while macular membrane with the opposite texture.2Three of four membranes associated with idiopathic macular membrane demonstrated a few diverse cells,including predominant glials, fibrocytes and macrophages. While the other one with ILM demonstrated a lot cells with predominant glials.3Six of seven ILM peeling from IMH hardly showed any cells.However, we observed slit-like hypodense areas with cells immigration in the ILM.The other specimen showed a lot diverse cells.4The nine secondary macular membranes demonstrated remarkable diverse cells and fiber trabs,which showed asymmetry distribution.5Tissues from3macular holes showed a basement membrane ultrastructure with one side smooth the other side rough.Tissue from epimacular membrane showed cellular elements and intercellular substance.Conclusion:1idiopathic macular membrane demonstrated a few diverse cells,including predominant glials, fibrocytes and macrophages. Secondary macular membranes have more cells and more complex structure compared to the idiopathic one,which demonstrates that their pathogenesis are different.2The ILM derived from IMH seldom showed cells,so it is likely that vitreous traction play the important role in the formation of IMH.3The defection of ILM in macular may lead to the idiopathic macular membrane.