Effect of membrane peeling on the ganglion cell inner-plexiform layer in glaucomatous eyes with idiopathic epiretinal membrane.

PURPOSE: To evaluate the impact of membrane peeling for idiopathic epiretinal membrane (iERM) on ganglion cell–inner plexiform layer (GCIPL) thickness in eyes with and without primary open-angle glaucoma (POAG). METHODS: A total of 120 eyes (mean age 67.5 ± 10.0 years, female: 59%) were divided into four groups (n = 30 each): (1) POAG with iERM that underwent surgery, (2) non-glaucomatous with iERM that underwent surgery, (3) POAG without iERM, and (4) healthy control. Patients with iERM underwent pars-plana vitrectomy (PPV) with ERM and internal limiting membrane (ILM) peeling. GCIPL thickness within a 4 × 4.8 mm elliptical area was measured using Cirrus OCT (ZEISS, Dublin, CA) at baseline, 6 months, and 12 months postoperatively. Data collected included demographic and clinical parameters, best corrected visual acuity (BCVA), and intraocular pressure (IOP). RESULTS: A significant three-way interaction was observed between glaucoma, surgery, and time. POAG with iERM that underwent membrane peeling demonstrated greatest thinning, with mean change of − 9.40 μm at 6 months (95% CI: −15.07, − 3.73) and − 10.37 μm at 12 months (95% CI: −15.77, − 4.97), compared to all other groups (p < 0.001). BCVA significantly improved in non-glaucomatous eyes that underwent membrane peeling (p = 0.005), while remaining stable in the other groups. IOP remained stable across all time points. CONCLUSIONS: PPV with ILM and ERM peeling is associated with significant GCIPL thinning in glaucomatous eyes. These findings suggest a synergistic effect between glaucoma and surgical intervention, underscoring the need for caution when considering ILM peeling in glaucomatous patients.