Short-Term Outcomes of Gonioscopy-Assisted Transluminal Trabeculotomy in Patients with Advanced Glaucoma

Purpose: To review the results of gonioscopy-assisted transluminal trabeculotomy (GATT) in patients with advanced glaucoma. GATT has shown efficacy in mild to moderate cases of glaucoma. Its efficacy in advanced glaucoma is uncertain, though recent studies show promising short-term outcomes. Methods: A retrospective chart review of advanced glaucoma patients undergoing GATT with or without cataract surgery from January 2018 to April 2023 was conducted. Complete success was defined as intraocular pressure (IOP) <14 mmHg with ≥30% reduction from baseline (Criteria A) or IOP <18 mmHg and/or ≥20% reduction (Criteria B), without antiglaucoma medications. Qualified success was defined as attainment of the same with a maximum of 2 medications. Results: A total of 69 eyes from 60 patients (mean age, 61.2 ± 15.3 years) were included in the study. The mean IOP decreased from 24.9 ± 10.7 mmHg preoperatively to 12.1 ± 3.0 mmHg at 6 months postoperatively. At 6 months, the complete success rate (based on Criteria A) was 66.7%, with an overall success rate of 81.9%. By 1 year ( n = 52), these rates were 51.9% and 65.4%, respectively. Using Criteria B, the complete success rate was 74.2%, and the overall success rate was 95.4% at 6 months, decreasing to 57.7% and 82.7% at 1 year. Patients who had used antiglaucoma medications for <2 weeks before surgery showed significantly higher success rates at both 6 months ( P = 0.01) and 1 year ( P = 0.019). Combining GATT with cataract surgery also improved success rates at 6 months ( P = 0.005). In addition, six eyes with previously failed trabeculectomy achieved success at 6 months, with five remaining successful at 1 year. Three eyes experienced delayed bleeds with an IOP spike, all of which met failure criteria during the follow-up. Conclusions: GATT demonstrates encouraging short-term outcomes in advanced glaucoma, particularly in treatment-naïve patients and those undergoing combined cataract surgery. However, delayed bleeds can lead to IOP spikes and treatment failure. GATT may be considered as a viable surgical option in treatment naïve patients with advanced glaucoma. Its efficacy is bolstered when combined with cataract surgery.