Purpose: To report the long-term follow-up results of nonvitrectomizing vitreous surgery for idiopathic epiretinal membrane (ERM). Design: Nonrandomized comparative case series. Participants: Thirty patients were followed up for at least 5 years after nonvitrectomizing vitreous surgery. Intervention: Epiretinal membranes were peeled without infusion of balanced salt solution and removal of the vitreous. The data from the fellow eye was the control data. Main Outcome Measures: We examined the visual acuities (VAs), objective refractions, and slit lamp and Scheimpflug photographs from the preoperative and the final examinations of both eyes. Quantitative assessment of the progression of nuclear sclerosis was performed by densitometry analysis using Scheimpflug photography. The recurrence rate of ERM was determined. Results: The follow-up periods ranged from 60 to 102 months (mean± standard deviation, 72.2± 11.0 months). The patient ages ranged from 52 to 76 years (68.8± 6.3 years). The final VA improved or stabilized within 2 lines in 29 of 30 eyes (96.7% ). No unilateral progression of nuclear sclerosis occurred in any cases. The mean preoperative and postoperative refractions without additional surgery were- 0.4± 2.9 diopters (D) and- 0.2± 3.0 D in the operated eyes, respectively, and- 0.2± 2.5 D and 0.1± 2.4 D, respectively, in the unoperated fellow eyes. The mean differences in the refractive error between both eyes (operated eye data minus fellow eye data) were- 0.2± 0.7 D before surgery and- 0.3± 0.8 D after surgery (P=0.319, paired t test). The mean preoperative and postoperative nuclear densities in 16 patients were 69± 14 nuclear density units (NDUs) and 76± 12 NDUs in the operated eyes and 71± 14 NDUs and 78± 14 NDUs in the fellow eyes, respectively. The mean preoperative and postoperative differences in nuclear densities in both eyes were - 2± 2 NDUs and- 2± 5 NDUs, respectively (P=0.836, paired t test). The ERM recurred in 10 eyes (33% ), and 3 eyes underwent conventional vitrectomy combined with cataract surgery. Conclusions: Unilateral nuclear sclerosis did not progress for at least 5 years after nonvitrectomizing vitreous surgery. The recurrence rate of ERM appeared to be higher than that after conventional vitreous surgery. Purpose: To report the long-term follow-up results of nonvitrectomizing vitreous surgery for idiopathic epiretinal membrane (ERM). Design: Nonrandomized comparative case series. Participants: Thirty patients were followed up for at least 5 years after nonvitrectomizing vitreous surgery. Intervention: Epiretinal membranes were peeled without infusion of balanced salt solution and removal of the vitreous. The data from the fellow eye was the control data. Main Outcome Measures: We examined the visual acuities (VAs), objective refractions, and slit-lamp and Scheimpflug photographs from the preoperative and the final examinations of both eyes. Quantitative assessment of the progression of nuclear sclerosis was performed by densitometry analysis using Scheimpflug photography. The recurrence rate of ERM was determined. Results: The follow-up periods ranged from 60 to 102 months ( mean ± standard deviation, 72.2 ± 11.0 months). The patient ages ranged from 52 to 76 years (68.8 ± 6.3 years). The final VA improved or stabilized within 2 lines in 29 of 30 eyes (96.7%). No unilateral progression of nuclear sclerosis occurred in any cases. The mean preoperative and postoperative refractions without additional surgery were- 0.4 ± 2.9 diopters (D) and- 0.2 ± 3.0 D in the operated eyes, respectively, and -0.2 ± 2.5 D and 0.1 ± 2.4 D, respectively, in the unoperated fellow eyes. The mean differences in the refractive error between both eyes (operated eye data minus fellow eye data) were -0.2 ± 0.7 D before surgery and- 0.3 ± 0.8 D after surgery (P = 0.319, paired t test). The mean preoperative and postoperative nuclear densities in 16 patients were 69 ± 14 nuclear density units (NDUs) and 76 ± 12 NDUs in the operated eyes and 71 ± 14 NDUs and 78 ± 14 NDUs in the fellow eyes, respectively. The mean preoperative and postoperative differences in nuclear densities in both eyes were - 2 ± 2 NDUs and- 2 ± 5 NDUs, respectively (P = 0.836, paired t test). The ERM recurred in 10 eyes (33%), and 3 eyes underhad conventional vitrectomy combined with cataract surgery. Conclusions: Unilateral nuclear sclerosis did not progress for at least 5 years after nonvitrectomizing vitreous surgery.