Oct changes after idiopathic macular epiretinal membrane removal with internal limiting membrane peeling : 1 year follow up

Purpose:To analyze long term anatomical outcomes after idiopathic macular epiretinal membrane (ERM) removal with internal limiting membrane (ILM) peeling. Methods:A retrospective, observational case series of 24 eyes that underwent three-port pars plana vitrectomy for ERM was conducted. In all the eyes ERM removal and Brilliant Blue G assisted ILM peeling were performed by the same surgeon (SDC). Visual acuity examination (ETDRS chart) and OCT assessment of the macular profile were performed preoperatively and postoperatively on day 1, 7 and 14 and at 1, 3, 6 and 12 months after surgery. We divided all patients in 2 groups considering visual acuity. The correlation between the postoperative BCVA and foveal microstructural findings was evaluated Results:Visual acuity stayed the same or with 1 line improvement in 7 patients (29.16%, Group A)and improved by two or more lines of vision in 17 patients (70.84%, Group B) at twelve months. Central retinal thickness decreased significantly after surgery: the mean thickness was 453.7+/-115.4 micron before surgery and 295.4+/-73.2 micron twelve months after surgery. None of the subjects had increasing foveal thickness twelve months after surgery. Inner hyper-reflective structure, attributable to the internal limiting membrane, could not be detected in 100% of eyes on day 1 and 7 after surgery in both group. In 71.4% of patients of group A and 75% of patients in group B a new inner hyper-reflective structure could be detected at 30+/-14 days after surgery. No recurrence of ERM was observed. Conclusions:ERM removal with ILM peeling is nowadays a safe and successful surgery for vitreoretinal interface syndrome. Many authors described a correlation between postoperative visual acuity and final foveal thickness. We observed that inner hyper-reflective structure, attributable to the internal limiting membrane, becomes newly detectable after 30+/-14 days after surgery in 70.9% of the patients and this doesn’t seem to have any influence on final visual outcome.