Five-Year Clinical Outcomes of Inferior Quadrant Trabectome Surgery for Open Angle Glaucoma

Abstract

Précis: This retrospective study of 264 eyes having inferior quadrant trabectome surgery confirms its safety and relative effectiveness. Most patients however still require IOP-lowering agents, and a considerable proportion may need additional glaucoma surgery. Purpose: To report outcomes from a large single-center cohort of inferiorly-applied trabectome surgery. Patients and Methods: Retrospective review of patients undergoing trabectome surgery for chronic open angle glaucoma (COAG) at the University Eye Clinic Bonn, Germany, from 2012 to 2020. Results: Two hundred sixty-four eyes of 206 patients with COAG were included. The mean review period was 45.43 (range 12–101) months. One hundred five eyes (39.8%) underwent standalone surgery, of which 74 were pseudophakic and 31 phakic. The mean preoperative IOP was 17.58 mm Hg (range 12–50 mm Hg). One hundred five eyes (39.8%) developed a ‘failure event’ according to pre-defined criteria at a mean interval of 14.8 months postoperative. In absolute terms, 211 patients (79.9%) had a long-term IOP >14 mm Hg at 7.6 months, 174 patients (65.9%) >16 mm Hg at 10.6 months, 127 patients (48.1%) >18 mm Hg at 10.9 months, and 77 patients (29.2%) >21 mm Hg at 11.1 months. Over a five-year period, overall mean IOP remained stable at 13 mm Hg. The majority of patients were still on glaucoma drops (the mean number reduced from 2.9 to 2.7 agents). Subgroup analyses showed that a higher preoperative IOP was a positive predictor for failure, whereas combined surgery (with phaco) had better IOP outcomes (16.5 mm Hg vs. 19.3 mm Hg, respectively). Forty-one patients (15.5%) developed minor complications: 22 had high postoperative IOP within 3 months, 11 developed a self-resorbing hyphema, and 6 had fibrinous uveitis. Conclusions: Trabectome surgery is a safe and relatively effective procedure for lowering IOP, but most patients still need IOP-lowering agents, and a considerable proportion may need additional glaucoma surgery within a relatively short time. Inferior quadrant treatment may result in inferior IOP outcomes when compared with nasal quadrant surgery.