Abstract: Objective To observe the long-term clinical effect of partial vitrectomy on idiopathic epiretinal membrane (IERM), and compared with conventional vitrectomy. Design Retrospective comparative case series. Participants 68 Cases (68 eyes) of IERM surgery at Nanjing Drum Tower Hospital. Methods According to different surgical methods, 34 cases (34 eyes) of partial vitrectomy with preservation of the anterior vitreous body combined with removal of the IERM and inner limiting membrane were selected as the partial resection group (from September 2019 to August 2022), while 34 cases (34 eyes) of conventional vitrectomy combined with removal of the IERM and inner limiting membrane were selected as the conventional resection group (from September 2017 to August 2019). The median follow-up time was 16.0 (12.0, 23.8) months in the partial resection group and 15.5 (13.0, 20.5) months in the conventional resection group, compare the operation time, the best corrected visual acuity (BCVA), intraocular pressure (IOP), and central retinal thickness(CRT) between the two groups before and after operation, and observe the occurrence of intraoperative and postoperative complications. Main Outcome Measures Operation time, BCVA, IOP, CRT and the occurrence of intraoperative and postoperative complications. Results In the partial resection group, LogMAR BCVA at the last follow-up after surgery was 0.3 (0.2, 0.4), which was significantly higher than that before surgery 0.8 (0.68, 1.00) (Z=-5.121, P=0.001). The CRT at the last follow-up was (374.35±128.69) μm, which was significantly lower than that before surgery (513.79±148.49)μm (t=7.221, P=0.001). There was no significant difference in IOP between postoperative follow-up at all time and preoperative (all P＞0.05). 3 eyes (8.82%) had mild retinal hemorrhage. The epiretinal membrane recurred in 1 eye (2.94%) 18 months after surgery. The mean operation time in the partial resection group (36.12±2.49) minutes, it was significantly shorter than that in the conventional resection group (42.08±2.36) minutes (t=-10.124, P=0.001). The IOP (12.21±3.12)mmHg in the conventional resection group was lower than that in the partial resection group (14.79±2.17)mmHg one day after surgery (t=3.969, P=0.001). There was no significant difference in BCVA and CRT between the two groups before and after operation (all P>0.05). In the conventional resection group, mild retinal hemorrhage occurred in 2 eyes (5.88%) and iatrogenic retinal hole occurred in 1 eye (2.94%). Fourteen months after surgery, the epiretinal membrane recurred in 1 eye (2.94%), and the retinal atrophy under the upper vascular arch in 1 eye (2.94%). Conclusion Partial vitrectomy is a safe and effective method for IERM, with the same effect as conventional vitrectomy, but shorter surgical time, less postoperative intraocular pressure fluctuations, and fewer complications. (Ophthalmol CHN, 2024, 33: 419-423)

Key words: partial vitrectomy, the epiretinal membrane, complications