Clinical Outcomes of Gonioscopy-Assisted Transluminal Trabeculotomy in Eyes After Failed Trabeculectomy.

Background: This study aims to present the clinical outcomes, safety profile, and mid-term results of gonioscopy-assisted transluminal trabeculotomy (GATT) in eyes with failed trabeculectomy. Methods: The studied group consisted of 62 patients after failed trabeculectomy. All patients underwent GATT, as a standalone procedure or in combination with cataract surgery (Phaco-GATT), between 2021 and 2023 and had at least 12 months of follow-up. The patients were examined at 1 day, 7 days, 1 month, 3 months, 6 months, and 12 months after surgery, with evaluation of visual acuity, intraocular pressure (IOP), number of antiglaucoma drops, and possible surgical complications. Results: The mean IOP before surgery was 37.22 ± 9.07 mmHg, and after the GATT procedure, it significantly decreased to 15.91 ± 5.28 mmHg at the 12-month follow-up. A comparison of patients with one or more previous antiglaucoma procedures showed no differences. A comparison of the degrees of successful canulating and deroofing of Schlemm's canal revealed no statistical significance concerning IOP values or the number of medications. When comparing the IOP between the patients after standalone GATT and Phaco-GATT, a tendency for higher IOP values in the latter group was observed. In 21 (33.3%) patients, hyphema affecting visual acuity was observed early after surgery, which resolved spontaneously. Six patients (9.7%) needed additional surgery to obtain the target pressure. Conclusions: GATT is an effective and safe IOP-lowering surgical option in open-angle glaucoma patients with failed trabeculectomy.