Abstract
OBJECTIVES: Glaucoma is the leading cause of irreversible blindness worldwide, with primary open-angle glaucoma (POAG) being the most common type. Trabeculectomy is currently the primary surgical treatment for POAG; however, its long-term efficacy remains suboptimal. This study aims to compare the therapeutic efficacy and safety of trabeculectomy combined with Schlemm canal incision (TCSCI) with trabeculectomy alone in order to provide new insights for POAG management. METHODS: In this retrospective case-control study, 47 patients (47 eyes) diagnosed with POAG at the Ophthalmology Center of Xiangya Hospital between May 2019 and May 2023 were included. Patients undergoing combined trabeculectomy and Schlemm canal incision were assigned to the TCSCI group, whereas those undergoing trabeculectomy alone were assigned to the trabeculectomy group. Postoperative assessments or follow-up were conducted on postoperative day 1 and at 1 week, 1 month, 2 months, 3 months, 6 months, 1 year, and 2 years. Best-corrected visual acuity, intraocular pressure (IOP), number of glaucoma medications, surgical success rate, and intraoperative and postoperative complications were compared between groups. RESULTS: No significant difference was found in baseline data between the TCSCI group and trabeculectomy group (all P>0.05). There were no statistically significant differences in visual outcomes between the 2 groups or within each group at any postoperative time point (all P>0.05). The IOPs in the 2 groups at all postoperative time points were lower than those before surgery (all P<0.05). On postoperative day 1, there was no significant difference in IOP between the 2 groups (P>0.05). However, at subsequent time points, the IOP in the TCSCI group was significantly lower than in the trabeculectomy group (all P<0.05). The number of glaucoma medications used at each postoperative time point in both groups was significantly lower than before surgery (all P<0.05). No statistically significant differences were in the number of glaucoma medications used between the 2 groups at any postoperative time point (all P>0.05). The qualified and complete success rates were 89.9% and 75.9% in the TCSCI group, and 74.9% and 56.4% in the trabeculectomy group, the differences between the 2 groups were not statistically significant (both P>0.05). When using the 6 to 17 mmHg (1 mmHg=0.133 kPa) and 6 to 14 mmHg IOP criteria, the TCSCI group had much higher success rates compared with the trabeculectomy group (all P<0.01). At postoperative 2 years, 68.4% patients in the TCSCI group and 61.9% patients in trabeculectomy group formed functional blebs (diffuse type and microcapsule type). No significant difference between the IOP of patients with functional blebs (11.77±2.24) mmHg and those with non-functional blebs (14.33±6.71) mmHg in TCSCI group (P=0.22). In the trabeculectomy group, the IOP of patients with functional blebs significantly lower than that of patients with non-functional blebs [(13.31±1.60) mmHg vs (20.75±4.92) mmHg, P<0.001]. No severe complications such as explosive suprachoroidal hemorrhage, hypotonic maculopathy, or endophthalmitis occurred in either group. CONCLUSIONS: Both TCSCI and trabeculectomy effectively lower IOP and reduce the need for postoperative IOP-lowering medications in POAG patients. Compared with trabeculectomy alone, TCSCI offers a dual outflow pathway through Schlemm canal and external filtration, representing a safe and effective surgical option for POAG.