ObjectiveTo observe and analyze changes in macular ganglion cell complex (GCC) parameters after trabeculectomy in primary open-angle glaucoma (POAG) patients and their relationship with visual function. MethodsA retrospective clinical study. From January 2022 to June 2024, 105 POAG patients (105 eyes) diagnosed and undergoing trabeculectomy at Department of Ophthalmology, Daqing Longnan Hospital were included. All patients underwent examinations including uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), visual field, and optical coherence tomography (OCT). The patients were divided into the mild group, the moderate group and the severe group according to the degree of optic nerve damage, with 36, 42 and 27 cases respectively. According to the BCVA 3 months after the operation, the patients were divided into the good visual recovery group and the poor visual recovery group, with 63 and 42 cases respectively. OCT was used to measure the average GCC thickness in the overall macular area (GCC-Avg), superior hemisphere (GCC-Sup), and inferior hemisphere (GCC-Inf). Generalized linear mixed-effects models and restricted cubic splines (RCS) were used to analyze the relationship between GCC thickness and optic nerve damage severity. Multiple linear regression analyzed the relationship between GCC parameter changes and visual acuity recovery. Stepwise regression assessed the impact of optic nerve damage severity and GCC parameter changes on visual acuity recovery. Receiver operating characteristic (ROC) curves and area under the curve (AUC) were used to evaluate the predictive value of GCC parameter changes for postoperative visual recovery in patients with different nerve damage severities. A mediating effect model was constructed to analyze the mediating effect of GCC thickness between optic nerve damage severity and postoperative visual recovery. ResultsSignificant differences were found in GCC-Avg, GCC-Sup, and GCC-Inf thicknesses among the different optic nerve damage severity groups (F=5.761, 18.199, 7.529; P＜0.05). Generalized linear mixed-effects models and RCS analysis revealed a significant nonlinear dose-response relationship between GCC thickness and severe nerve damage (nonlinear test P＜0.05). Significant differences were observed between the good and poor recovery groups in preoperative and postoperative intraocular pressure (t=2.839, 3.979) and optic nerve damage severity (χ2=15.418) (P＜0.05). Preoperatively, and at 1 week and 1 month postoperatively, the poor recovery group had significantly lower GCC-Avg (t=5.089, 5.983, 6.321), GCC-Sup (t=7.513, 9.342, 9.81), GCC-Inf (t=5.499, 6.279, 7.698) thicknesses, UCVA (t=15.194, 14.852, 18.758), and BCVA (t=16.129, 16.167, 21.798) compared to the good recovery group (P＜0.05). UCVA and BCVA improved significantly at 1 week, 1 month, and 3 months postoperatively in the good recovery group (P＜0.05). Multiple linear regression showed that GCC-Avg, GCC-Sup, and GCC-Inf thicknesses were positively correlated with UCVA and BCVA in patients with different nerve damage severities (P＜0.05). Optic nerve damage severity was positively correlated with visual recovery (P＜0.05), while GCC-Avg, GCC-Sup, and GCC-Inf were negatively correlated with visual recovery (P＜0.05). ROC curve analysis showed that GCC-Avg, GCC-Sup, and GCC-Inf thicknesses had AUC ＞0.7 for predicting postoperative visual recovery in POAG patients. The combined prediction using all three parameters yielded higher AUC, sensitivity, and specificity than any single parameter, indicating superior predictive performance. ConclusionVisual recovery after trabeculectomy in patients with open-angle glaucoma correlates with the extent of optic nerve damage and the thickness of the ganglion cell complex in the macula, and ganglion cell complex thickness mediates the modulation between the extent of optic nerve damage and postoperative visual recovery.