Surgical Outcomes of Gonioscopy-Assisted Transluminal Trabeculotomy (GATT) in Patients with Open-Angle Glaucoma - A Retrospective Case Series.

Abstract

To evaluate the outcome of gonioscopy-assisted transluminal trabeculotomy (GATT) in patients with open-angle glaucoma (OAG). A retrospective case series of patients with uncontrolled OAG treated by GATT at the cantonal Hospital Lucerne, a tertiary referral center, between October 2018 and July 2019 with a minimal 6-month follow-up period. Main outcome measures were intraocular pressure (IOP), number of antiglaucoma medications, and complications. Thirty-one eyes of 29 patients with a mean age of 70.9 years and a minimal follow-up period of 6 months were included in this study. Twenty eyes were treated for pseudoexfoliation (64.5%), seven for primary open-angle (22.6%), three for pigmentary (9.7%), and one for traumatic (3.2%) glaucoma. Twenty-six eyes had data at the 6-month follow-up and 12 eyes at the 12-month follow-up. Twenty-two eyes (70.9%) were pseudophakic prior to the operation. Mean preoperative IOP was 33 mmHg (standard deviation [SD] 8.0 mmHg). The postoperative IOP was 13.9 mmHg [SD 2.2] at the 6- and 13.9 mmHg [SD 3.1] at the 12-month follow-up. The postoperative IOP evolution translated into a 58% decrease between 6 and 12 months (p < 0.001). Thirteen patients (41.9%) were treated with oral Diamox prior to GATT. The number of antiglaucoma medications decreased from a preoperative average of 2.9 [SD 1.2] to postoperative 1 [SD 1] drug (p < 0.001). The most frequent adverse event was the occurrence of postoperative hyphema. Hyphema was observed in 21 (68.0%), 7 (22.6%), and 2 (6.4%) eyes at days 1, 7, and 30 after GATT, respectively. Intraocular hypertension over 25 mmHg was seen in eight eyes (25.8%), and in four of them, a steroid response was suspected. One patient developed an anterior uveitis and a macular edema. GATT is an effective and safe intervention for OAG, particularly in pseudoexfoliation glaucoma (PEX). The advantages of GATT compared to filtration surgery are the low rate of long-term complications and that the intervention is feasible even when difficult conjunctival conditions are encountered.