Twenty-four patients that seek treatment at the Ophthalmology Department of The Federal University of São Paulo will be selected for this study. Inclusion criteria will be patients diagnosed with epiretinal membrane, macular hole or diabetic retinopathy (with or without vitreal hemorrhages, and/or macular edema, and/or vitreomacular traction). All must be indicated for vitrectomy surgery for the removal of the epiretinal membrane and/or internal limiting membrane.