Surgery Outcomes of Prolene Suture Gonioscopy Assisted Transluminal Trabeculotomy (GATT)– up to 4 years follow-up and Prognostic Factors

Abstract

Precis: Long-term success was achievable after GATT. GATT performed at early stage of glaucoma had better surgery outcomes. Trabeculoplasty may compromise surgery success. Purpose: To evaluate the long-term effectiveness of prolene suture gonioscopy assisted transluminal trabeculotomy (GATT) and identify factors that may affect surgical outcomes. Patients and Methods: This is a retrospective cohort study of adult patients with prolene suture GATT performed by a single surgeon at one medical center. Results: Of the 145 eyes from 124 patients studied, intraocular pressure was reduced from 22.1±7.8 to 15.1±3.2 and 15.1±3.5 mmHg, and the number of glaucoma medications was reduced from 3.2±1.1 to 1.3±1.4 and 1.4±1.5 at postoperative years 3 and 4, respectively. 93 and 71 eyes completed a 3 and 4-year follow-up, with 44% of the eyes at year 4 remaining medication free. Compared to eyes with combined GATT/cataract extraction (CE), eyes with GATT alone had significantly more preoperative medications and a higher reoperation rate (31% vs. 16.5%). Eyes with prior trabeculoplasty had a higher reoperation rate (28.8%) than those without (16.1%). Kaplan-Meier survival analysis revealed that GATT/CE eyes without trabeculoplasty had a longer median time to failure (48 mo) than GATT/CE eyes with trabeculoplasty (18 mo), and GATT eyes with or without trabeculoplasty (9 mo and 12 mo, respectively). Conclusion: Prolene suture GATT successfully reduced IOP. Eyes with more preoperative medications responded less well to GATT. Prior laser trabeculoplasty was associated with poorer outcomes. Further study is needed to verify these findings.