Outcome of gonioscopy-assisted transluminal trabeculotomy in glaucoma: 5-year results.

OBJECTIVE: Gonioscopy-assisted transluminal trabeculotomy (GATT) has gained popularity as a microinvasive glaucoma surgery procedure, yet long-term outcomes remain understudied. Our study evaluated the 5-year efficacy and safety of GATT. DESIGN: Multicentre retrospective cohort study. PATIENTS: Adult patients with open-angle glaucoma who underwent GATT with or without phacoemulsification between 2016 and 2019 were included. We excluded eyes with previous glaucoma surgery, angle-closure, or traumatic glaucoma. METHODS: The primary outcome was surgical success, defined as the absence of a need for reoperation or a laser procedure for uncontrolled intraocular pressure (IOP) or disease progression. Secondary outcomes additionally required IOP thresholds of ≤21, ≤18 and ≤15 mm Hg without an increase in anti-glaucoma medication (AGM) use. Five-year changes in IOP, AGM use, best-corrected visual acuity, OCT parameters, and adverse events also were assessed. RESULTS: In total, 74 eyes from 62 patients (mean age 59.1 ± 13.9 years; 54% male) were analysed, including 56 standalone GATT and 18 Phaco-GATT cases. Mean baseline IOP was 23.1 ± 8.0 mm Hg on 3.2 ± 1.3 AGMs. At 5 years, mean IOP decreased by 9.6 mm Hg (41.6% reduction), and AGM use decreased by 1.1 (34.4% reduction), both P < 0.001. Success rates varied from 28% to 51% on the basis of different criteria. Cox proportional hazards analysis identified greater success in the Phaco-GATT group (hazard ratio 0.23; P = 0.015) and lower success in eyes with previous selective laser trabeculoplasty (hazard ratio 2.5; P = 0.017). CONCLUSIONS: GATT provides sustained 5-year IOP and medication reductions with a favourable safety profile, supporting its use as an effective long-term option.