Gonioscopy-assisted transluminal trabeculotomy (GATT), combined with goniosynechialysis (GSL), can significantly reduce intraocular pressure (IOP) and the number of anti-glaucoma medications needed to treat primary angle closure patients, a study shows. However, GATT does not appear to produce better results than GSL with phacoemulsification (PEA) or PEA alone, according to the findings published in International Ophthalmology. 

Prior research suggested that GATT can lower IOP to about 15 mm Hg with or without medication in open-angle glaucoma patients, according to investigators. However, GATT is not a treatment of choice in angle closure patients because of the angle of the anterior chamber, which blocks the visibility of the trabecular meshwork during surgery. Investigators thought GATT might still be useful for these patients because long-term peripheral anterior synechiae causes the trabecular meshwork to malfunction, reducing aqueous outflow.

In this study, investigators tried to reform the anatomy of the anterior chamber angle in patients with primary angle closure by using GSL before performing GATT. They then analyzed outcomes pre- and post-surgery.

Primary angle closure patients who underwent GATT + GSL with or without PEA and intraocular lens (IOL) implantation between December 2016 and May 2018 were recruited. IOP and the number of anti-glaucoma medications were compared pre- and post-surgery. In total, 39 eyes of 30 patients, including 37 chronic angle closure glaucoma (CACG), 1 acute primary angle closure (APAC), and 1 plateau iris syndrome case were recruited. The mean preoperative IOP was approximately 21.8 mm Hg. Success was defined as achieving IOP less than or equal to 15 mm Hg (calculated from mean baseline IOP) with or without anti-glaucoma medication.

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The team found a success rate was 71.8% (28 eyes; P =.006) at the last follow-up visit. Specifically, mean postoperative IOP was lowered (to 15.1 mm Hg ± 3.8 mm Hg at 1 month, 14.4 mm Hg ± 1.2 mm Hg at 3 months, 14.8 mm Hg ± 2.1 mm Hg at 6 months, 14.5 mm Hg ± 0.8 mm Hg at 1 year, and 15 mm Hg at 2 years, P <.001, P =.0012, P =.001, P =.028, and P =.317, respectively). The mean overall postoperative IOP at the last follow-up was 15.1 mm Hg (± 4.4 mm Hg, P <.001). Mean preoperative number of anti-glaucoma medications was 3.5 (± 1.4). Mean postoperative number of antiglaucoma medications was reduced (to 1.5 ± 1.4 at 1 month, 0.9 ± 0.9 at 3 months, 1.4 ± 1.4 at 6 months, 1.5 ± 0.5 at 1 year, and 2 at 2 years (P <.001, P =.01, P =.002, P =.028, and P =.317, respectively). The mean overall postoperative number of antiglaucoma medications was 1.1 (± 1.2, P <.001). No significant difference was found between the IOP-lowering effect in subgroup analysis.

Researchers note several limitations of their study, including the dissimilarity of the number of cases between the groups and that the loss ratio of the follow-up cases was particularly high.

Disclosure: A study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.


Chira-Adisai T, Mori K, Kobayashi A, et al. Outcomes of combined gonioscopy-assisted transluminal trabeculotomy and goniosynechialysis in primary angle closure: a retrospective case series. Int Ophthalmol. Published online January 3, 2021. doi:10.1007/s10792-020-01676-y.