Epiretinal membrane(ERM)is a relatively common macular disease that forms along the surface of the internal limiting membrane(ILM)of the retina to some reason. The pathogenesis is not clear. Microincision vitrectomy surgery has been confirmed as a minimally invasive and very safe modality of treatment. Deciding when to perform a vitrectomy can be difficult. There are many factors which can affect the postoperative visual acuity, such as age, the thickness of macular, integrity of photoreceptor inner segment/outer segment(IS/OS)junction.