Gonioscopy-Assisted Transluminal Trabeculotomy (GATT): Efficacy, Safety, and Long-Term Outcomes in Open-Angle Glaucoma

Abstract

Gonioscopy-assisted transluminal trabeculotomy (GATT) is an ab interno, conjunctival-sparing minimally invasive glaucoma surgery that reduces resistance at the trabecular meshwork and the inner wall of Schlemm’s canal. It has emerged as an effective option for lowering intraocular pressure and reducing dependence on antiglaucoma medications in patients with open-angle glaucoma, while preserving the conjunctiva for possible future filtration procedures. Reported advantages include the absence of bleb-related complications, a low risk of prolonged hypotony, possible synergy with cataract extraction, and relatively rapid postoperative recovery. Current evidence demonstrates meaningful and sustained intraocular pressure reduction with generally favourable safety outcomes, although long-term failure and reoperation may occur, particularly in patients with high preoperative intraocular pressure or postoperative pressure spikes. Transient hyphema is the most frequently reported complication, whereas serious late complications are uncommon. GATT has also shown potential effectiveness in advanced, refractory, and previously operated open-angle glaucoma, provided that patients are carefully selected and closely followed. Overall, the available literature supports GATT as a safe and effective conjunctival-sparing alternative to conventional glaucoma surgery, with the additional advantage of maintaining future surgical options.