Objective To compare the clinical efficacy of 25G+and 27G+pars plana vitrectomy(PPV)in the treat-ment of idiopathic epiretinal membrane(iERM).Methods A total of 50 iERM patients(50 eyes)who were admitted to the Third Affiliated Hospital of Xinxiang Medical University from December 2019 to August 2022 were selected as the research subjects.These patients were divided into the control group and observation group based on different surgical methods,with 25 patients(25 eyes)in each group.Patients in the control group received 25G+PPV treatment,while patients in the observation group received 27G+PPV treatment.The surgical duration and postoperative 1-day incision subconjunctival hemorrhage and e-dema of patients in two groups were compared;central macular thickness(CMT)was measured by optical coherence tomo-graphy before surgery,1 day,1 week,1 month,and 3 months postoperatively in the two groups.Visual acuity of patients in both groups was assessed according to the early treatment diabetic retinopathy study(ETDRS)visual acuity chart.Intraocular pressure was measured by using a non-contact Callon tonometer.Complications,such as intraoperative macular injury,retinal hole,postoperative choroidal detachment,retinal hemorrhage,retinal detachment,and intraocular infection,were observed in both groups.Results The surgical duration of patients in the observation group was significantly shorter than that in the control group(t=2.314,P＜0.05).The extent of subconjunctival hemorrhage and edema of patients in the observation group was significantly smaller than that in the control group(t=13.706,P＜0.01).The ETDRS visual acuity of patients at 1 day,1 week,1 month,and 3 months after surgery in both groups was significantly higher than that before surgery(P＜0.05).There was no signifi-cant difference in ETDRS visual acuity of patients between the two groups at 1 day,1 week,1 month,and 3 months postoperatively(P＞0.05).At 1 day after surgery,the intraocular pressure of patients in the observation group was significantly higher than that in the control group(P＜0.05).At 1 week,1 month,and 3 months after surgery,there was no significant difference in intraocular pressure of patients between the two groups(P＞0.05).Two patients in the control group experienced transient ocular hypotension 1 day after surgery,while no such complication was observed in the observation group.Patients in both groups presented with varying degrees of retinal nerve epithelial layer traction,retinal edema,thickening,and vascular distortion before surgery.At 1 day after surgery,epiretinal membrane traction was relieved in both groups,and there was a significant improvement in the anatomical structure of the macular area compared to preoperative conditions.At 1 day,1 week,1 month,and 3 months after surgery,the CMT of patients in both groups was reduced compared to preoperative values(P＜0.05);there was no significant difference in CMT of patients between the two groups at 1 day,1 week,1 month,and 3 months after surgery(P＞0.05).In the control group,18 eyes(72.0％)were sutured at the scleral puncture sites due to leakage,while no suturing was performed in the observation group.Patients in both groups completed the surgery successfully,without any intraoperative complications such as macular injury or retinal hole.During the 3-month follow-up,no postoperative complications such as choroidal detachment,retinal hemorrhage,retinal detachment,or intraocular infection were observed in both groups.Conclusion Both 27G+PPV and 25G+PPV have good clinical effects and high surgical safety in the treatment of iERM.Compared with 25G+PPV,27G+PPV can shorten the surgical duration,better maintain postoperative intraocular pressure stability,and reduce the range of subconjunctival bleeding and edema.