Intraocular pressure spikes after gonioscopy-assisted transluminal trabeculotomy (GATT).

Purpose: Intraocular pressure (IOP) spikes (IOP > 30 mmHg or > 10 mmHg above baseline IOP) are a common and worrisome complication of gonioscopy-assisted transluminal trabeculotomy (GATT). The purpose of this study is to identify risk factors for IOP spikes and to describe their characteristics, management, and clinical course in a large cohort of patients.

Methods: A retrospective, single-center study which included 217 consecutive eyes of patients that underwent GATT between December 2019 and April 2022 with follow-up of at least 90 days.

Results: IOP spikes occurred in 52 of 217 (24%) eyes. Spikes occurred in 15.5% of patients in whom pre-operative IOP-lowering medications were continued after surgery (90 eyes), and in 29.9% in whom IOP-lowering medications were stopped after surgery (127 eyes). Spikes were diagnosed at a mean of 7.7 ± 6.5 days after surgery. All IOP spikes occurred within the first month of surgery. The mean duration of a spike was 4.9 ± 5.4 days. Management of IOP spikes included adding a mean of 3.13 ± 1.7 groups of glaucoma medications. Thirty-seven (72.5%) eyes were treated with oral carbonic anhydrase inhibitor, 11 (21.6%) were treated with IV mannitol, and anterior chamber paracentesis was performed in 16 (31.4%). Six (11.8%) eyes underwent additional glaucoma surgery to control IOP. Patients that continued their pre-operative IOP-lowering medications after surgery were 2.3 times less likely to develop a spike as compared to patients who discontinued their medications (P = 0.016). Spikes were found to be a risk factor for failure of GATT.

Conclusions: IOP spikes are a common occurrence after GATT. They most commonly appear during the first two post-operative weeks and usually resolve with topical and systemic IOP-lowering treatment. The continuation of IOP-lowering medications after GATT is recommended to lower the risk of IOP spikes.