Malignant Glaucoma Following Gonioscopy-Assisted Transluminal Trabeculotomy

In this observational case-series study, we aimed to report malignant glaucoma (MGL) occurence in 4 consecutive cases (4 women; mean age, 60±11.0 y) after gonioscopy-assisted transluminal trabeculotomy (GATT) between January 2021 and September 2024 and to evaluate clinical characteristics and treatment outcomes. All patients had primary angle closure glaucoma (PACG) before GATT. They were hypermetropic (+1.75 to +2.00 diopters) and had 360-degree peripheral anterior synechia (PAS) on gonioscopy. Axial length and anterior chamber depth values ranged from 20.85 to 21.22 mm and 1.92 to 2.04 mm, respectively. Preoperative plateau iris appearance was confirmed by using ultrasound biomicroscopy and anterior segment optical coherence tomography in all cases. Intraocular pressure (IOP) ranged from 36 to 45 mm Hg before GATT with maximal antiglaucoma therapy. MGL was diagnosed on the first postoperative day after GATT. IOP levels at the time of MGL diagnosis ranged from 19 to 29 mm Hg. Due to no response to initial medical treatment, one case underwent pars plana vitrectomy with subsequent Nd:YAG laser hyaloidotomy for MGL recurrence, and, other 3 cases received irido-zonulo-hyaloido-vitrectomy (IZHV). The incidence of post-GATT MGL development was 1.3% (4/300 eyes). We first describe post-GATT MGL occurrence in 4 consecutive cases that had advanced PACG. They all had preoperative plateau iris appearance. Proper detection and adequate treatment of MGL are necessary to provide good IOP control and to prevent further angle damage after GATT.