Surgical Success and Predictive Factors in Patients Undergoing Gonioscopy-Assisted Transluminal Trabeculotomy

This retrospective study aimed to evaluate the one-year surgical success of gonioscopy-assisted transluminal trabeculotomy (GATT) and identify prognostic factors influencing surgical outcomes in eyes diagnosed with open-angle glaucoma.

A total of 225 eyes (214 patients) treated with GATT between March 1, 2018, and June 1, 2024, were included in the study. Preoperative and postoperative data were analyzed. Complete surgical success (Criterion A) was defined as having an intraocular pressure (IOP) between 5 and 18 mmHg or at least a 30% reduction in IOP without the need for additional surgery. Overall success referred to achieving the same IOP with or without glaucoma medications. Surgical failure was defined as IOP >18 mmHg or <5 mmHg, significant vision loss, or the need for additional surgical intervention.

The mean age of patients was 64.4±11.9 years, and the mean axial length (AL) was 24.0±2.0 mm. The mean preoperative IOP was 26.7±7.3 mmHg, which decreased to 14.3±6.5 mmHg at 12 months postoperatively (p<0.05). The rate of complete success according to Criterion A was 41.3%, while the rate of overall success was 87.6%. Multivariate analysis revealed that higher preoperative IOP (odds ratio [OR]: 1.07; p=0.02), longer AL (OR: 1.3; p<0.01), and postoperative IOP spikes (OR: 5.18; p<0.01) were significantly associated with surgical failure. Patients who underwent circumferential (360°) GATT had significantly higher success rates compared to those who received hemi-GATT (OR: 4.69; p=0.01). Glaucoma stage, presence of pseudoexfoliation glaucoma, history of prior trabeculectomy, and vitrectomy were not significantly associated with surgical outcomes (p>0.05 for all).

GATT is an effective and safe surgical option for various types of glaucoma. Higher preoperative IOP, longer AL, and postoperative IOP spikes increase the risk of surgical failure, whereas circumferential GATT is associated with improved success rates. GATT can also be considered as a potential alternative for patients with prior glaucoma surgery or advanced-stage glaucoma.