Abstract: Objective To investigate the changes in retinal ganglion cell complex (GCC) thickness and retinal sensitivity after internal limiting membrane (ILM) peeling in idiopathic macular hole (IMH) patients, and to evaluate the impact of ILM peeling on the structure and function of the inner retina. Design Retrospective comparative case series. Participants A total of 24 IMH patients (21 females) who visited the hospital between October 2021 and December 2022 were included. Methods The patient's medical records were reviewed. The affected eyes were designated as the experimental group, while the contralateral healthy eyes served as the control group. All patients underwent PHACO+IOL+vitrectomy+internal limiting membrane (ILM) peeling+sterile air tamponade, with successful closure of the macular hole postoperatively. Best-corrected visual acuity (BCVA) was recorded preoperatively and 3 months postoperatively. Spectral-domain optical coherence tomography (SD-OCT) was used to measure the preoperative macular hole diameter and GCC thickness in both eyes 3 months postoperatively. Microperimetry-3 (MP-3) was employed to measure the macular mean sensitivity (MMS), central macular sensitivity (CMS), and retinal sensitivity in the 4°-12° sectoral regions of the experimental group preoperatively and 3 months postoperatively. The postoperative GCC thickness between the two groups, changes in retinal sensitivity in the experimental group before and after surgery, and the correlation between GCC thickness changes and postoperative retinal sensitivity were analyzed. Main Outcome Measures  BCVA, GCC thickness， MMS,CMS, retinal sensitivity in the 4°-12° sectoral regions. Results There were significant differences in GCC thickness among the four quadrants of the control group (F=20.444, P=0.000). The GCC thickness in the two nasal quadrants was significantly greater than that in the temporal quadrants, and the differences were statistically significant (both P=0.000<0.05). At three months postoperatively, the GCC thickness in the two nasal quadrants of the experimental group was significantly greater than that in the temporal quadrants (F=34.165, P=0.000), and the nasal GCC thickness was increased compared with that of the healthy eye (SN: t=-4.703, P=0.000; IN: t=-2.972, P=0.006). The GCC thickness in the inferior temporal quadrant of the experimental group was decreased compared with that of the healthy eye (t=2.247, P=0.034). Postoperative MMS and CMS were significantly improved compared with preoperative values (t=-7.346, -8.623, both P=0.000). There were no significant differences in mean retinal sensitivity across the four sectoral areas (4°–12°) before and after surgery (all P>0.05). No significant correlation was found between changes in GCC thickness in the four quadrants and the corresponding quadrant mean retinal sensitivity after surgery (all P >0.05). However, a potential trend was observed between thinning of GCC thickness in the inferior temporal quadrant and decreased mean retinal sensitivity (ρ=0.424, P=0.062). Conclusion The inferotemporal quadrant is the most susceptible region to mechanical injury during ILM peeling. Surgical manipulation in this area should be minimized to avoid repeated traction. Postoperatively, GCC thickness measurement should be incorporated into routine follow-up as a complementary indicator of ganglion cell damage, as visual acuity alone is insufficient to detect early structural changes.

Key words:  Idiopathic macular hole (IMH), Internal limiting membrane peeling, Ganglion cell complex, Microperimetry-3