Abstract:  Objective To evaluate the efficacy of gonioscopy-assisted ab interno canaloplasty combined with transluminal trabeculotomy (GABiC) for primary open-angle glaucoma (POAG). Design retrospective comparative case series. Participants Thirty eyes of 30 POAG patients (18 years old or more) who has not any previous laser or surgical therapy were treated by the same surgeon from Tongren Eye Center from Jun 2018 to Jan 2019. Methods Retrospective review of patients who underwent GABiC or gonioscopy-assisted transluminal trabeculotomy (GATT) with 3 months follow-up. Main Outcome Measures IOP, medication use, complications, the rate of qualified success and complete success. Results 7 eyes in the GABiC group and 23 eyes in the GATT group. At 3 months, mean IOP was 17.0±2.2 mmHg for GABiC group and 14.7±3.0 mmHg for GATT group (P=0.081) on 0.3±0.8 and 0.1±0.4 medications(P=0.865), respectively. The absolute success rates were 86% (6/7 cases) for GABiC group and 83% (19/23 cases) for GATT group (P=1.000), and the qualified success rates were 100% (7/7 cases) for GABiC group and 96% (22/23 cases) for GATT group (P=1.000). The two groups had similar complications of IOP spike (GABiC 14%, GATT 48%; P=0.193), ciliary detachment (GABiC 100%, GATT 100%) and hyphema (GABiC 57%, GATT 87%; P=0.120). Conclusion Both surgeries were effective in reducing IOP and glaucoma medications safely. GABiC is a feasible surgical option for POAG. Further study with even longer follow-up is needed. (Ophthalmol CHN, 2020, 29: 304-308)

Key words: gonioscopy-assisted transluminal trabeculotomy, ab interno canaloplasty, primary open-angle glaucoma, microinvasive glaucoma surgery