Long-term Outcomes of GATT for Glaucoma: ≥3 Year Follow-up at a UK Tertiary Center

At ≥3 years, GATT significantly lowered IOP and medication use in a diverse UK glaucoma cohort and subtype, with Afro-Caribbean ethnicity, non-360-degree trabeculotomy, and early postoperative IOP spikes identified as independent predictors of surgical failure.

To report the 5-year clinical outcomes of gonioscopy-assisted transluminal trabeculotomy (GATT) in a heterogenous glaucoma cohort at a major tertiary glaucoma center.

This is a single-center, multisurgeon, retrospective consecutive case series of all patients (111 eyes of 95 patients) who underwent GATT, with a minimum follow-up of 3 years (median: 5.1 y, range: 3-7 y) at the Birmingham Midland Eye Centre. The primary outcome was surgical success as defined by World Glaucoma Association criteria. Secondary outcome measures included intraocular pressure (IOP), number of medications, visual field parameters, retinal nerve fiber layer (RNFL) changes, further procedures, and complications.

Primary glaucoma was most common (68 eyes, 61.3%), predominantly open angle (43.2%), while secondary glaucoma comprised 38.7%, primarily uveitic (18.0%). Among these, 60 eyes (54.1%) underwent GATT alone, and 51 eyes (45.9%) had GATT with cataract surgery. The mean (SD) preoperative IOP significantly improved from 30.3 mm Hg (10.5) on 3.8 (1.1) medications to 17.5 mm Hg (7.7) on 2.2 (1.7) medications at the final follow-up. Qualified and complete success rates were 57.7% and 20.7%, respectively, with an overall failure rate of 42.3% and reoperation rate of 27.9%. Mean time to failure was 1.6 years (1.5), with 21.4% of failures occurring within the first postoperative year.

Overall, GATT provides a minimally invasive, effective alternative to traditional surgeries, with stable visual outcomes and a manageable reoperation rate, supporting its role in advanced glaucoma management. Identified risk factors for increased surgical failure include Afro-Caribbean ethnicity and IOP spike at 1 month and non-360 degrees GATT.