Surgical results of idiopathic and secondary epiretinal membrane

The aim of the study is to compare the surgical results of patients with an idiopathic and secondary epiretinal membrane (ERM) after pars plana vitrectomy and membranectomy. The medical records of 51 consecutive patients with ERM who underwent pars plana vitrectomy and membranectomy with a follow-up >1 year were reviewed retrospectively. Age, sex, best-corrected visual acuity (BCVA, logMAR), lens status, presence of additional removal of internal limiting membrane (ILM), and recurrence rate within 1 year after the operation were compared in the idiopathic and secondary ERM groups. Forty-one eyes had idiopathic ERM and 10 eyes had secondary ERM. Preoperative average BCVA values in the two groups were 0.47 and 0.70, respectively, and the postoperative average BCVA values were 0.28 and 0.18, respectively, with significant improvement postoperatively in both groups (p < 0.01, p < 0.01). The recurrence rate within 1 year after surgery in the idiopathic group was 4.88 % and that in the secondary group was 20 % (p = 0.03). The recurrence rate was 4.3 % in the idiopathic group with ILM removal and it was 5.9 % without ILM removal (p = 0.03). No case recurred within 1 year in the secondary group with ILM removal but the recurrence rate was 33.3 % in the group without ILM removal (p = 0.01). Although patients with secondary ERM gained better visual acuity improvement postoperatively, the recurrence rate was higher within 1 year than that of patients with idiopathic ERM. Removal of the ILM may lower recurrence rates.