Outcomes of gonioscopy-assisted transluminal trabeculotomy in advanced pigmentary glaucoma

Purpose To compare outcomes of gonioscopy-assisted transluminal trabeculotomy (GATT) over a 12-month period with trabeculectomy in patients with advanced pigmentary glaucoma (PG). Methods This was a pilot randomised controlled trial of patients with advanced PG (mean deviation worse than −12 dB), undergoing either GATT or a fornix-based trabeculectomy. Absolute success (criterion A) was defined as a postoperative intraocular pressure (IOP) between 6 and 18 mm Hg, with a drop of at least 30% from the treated preoperative value without need of any IOP-lowering medication. Success (criterion B) was also defined as per the target IOP, with an upper limit of 15 mm Hg for eyes with mean deviation (MD) between −12 and −24 dB, and 12 mm Hg or lower for MD values worse than −24 dB. Qualified success was a similar IOP standard on the same or fewer antiglaucoma medications. Results For GATT (n=10), mean preoperative IOP and number of glaucoma medications were 28.2±11.2 mm Hg and 4±0.8 that reduced to 11.8±2.5 mm Hg and 0.7 at 12 months postoperatively, while in the trabeculectomy (n=12) group, they were 27.3±5.5 mm Hg and 3.6±0.7 that reduced to 11.5±2.2 mm Hg and 0.5±0.9, respectively. All eyes (100%) achieved qualified success. Absolute success was 60% and 67.7% by criterion A and 50% and 58.3% by criterion B for GATT and trabeculectomy, respectively. Two eyes in the trabeculectomy group developed hypotony while none of the GATT group had any sight-threatening complications (p=0.4). Conclusions GATT alone demonstrated a significant reduction in IOP and number of glaucoma medications in patients with advanced PG.