25- Versus 27-Gauge Vitrectomy for Idiopathic Epiretinal Membrane: Operative Time and Outcomes in a Homogeneous Cohort

Background To compare operative efficiency, efficacy, and safety of 25-gauge (25G) versus 27-gauge (27G) microincision vitrectomy systems for idiopathic epiretinal membrane (ERM) surgery in a homogeneous cohort. Methods Retrospective, single-center series of consecutive eyes operated between March 2021 and January 2023, with ≥ 12-month follow-up. All surgeries were performed by the same vitreoretinal surgeon using a standardized platform. Outcomes included best-corrected visual acuity (BCVA, logMAR), intraocular pressure (IOP), central macular thickness (CMT), ERM–ILM peel time, core vitrectomy time, total surgical time, and 12-month metamorphopsia (Amsler grid). Intraoperative instrument use (light probe and vitrectomy cutter: single vs ≥ 2) was recorded. Results A total of 107 eyes were analyzed (27G, n = 68; 25G, n = 39). Baseline age, sex, and lens status did not differ between groups. ERM–ILM peel duration was longer with 25G (9.4 ± 2.5 vs 8.1 ± 2.2 min; P =  0.073). Core vitrectomy and total surgical times were longer with 27G (core: 27.8 ± 10.8 vs 21.8 ± 9.1 min, P  = 0.014; total: 45.6 ± 9.4 vs 38.1 ± 10.4 min, P  = 0.001). BCVA improved significantly in both groups with no between-group differences at any visit through month 12. During follow-up, IOP and CMT values were also similar between groups (all P > 0.05). Twelve-month metamorphopsia was statistically similar between the 27G and 25G groups (52.9% vs 41.0%; P = 0.235). Although 27G instruments are more flexible and occasionally deformed intraoperatively, the need to replace light probes or vitrectomy cutters due to bending was not significantly different from 25G (light 6/68 vs 1/39; cutter 4/68 vs 1/39; both P > 0.05). Conclusion In idiopathic ERM surgery, 25- and 27-gauge systems achieve similar 12-month visual and anatomical outcomes. Operative profiles differ: 27G is associated with longer core and total times, whereas 25G shows longer peeling time. These differences likely reflect instrument rigidity/flexibility rather than efficacy. Gauge selection may be individualized according to surgical priorities (time efficiency versus minimal incision).