Gonioscopy-Assisted Transluminal Trabeculotomy; A Review

Is GATT the Answer?

How to cite this article: Bhartiya S, Aktas Z, Ichhpujani P. Is GATT the Answer? J Curr Glaucoma Pract 2023;17(4):167-168.

Minimally Invasive Glaucoma Surgery: A Review of the Literature

Minimally invasive glaucoma surgery (MIGS) has emerged as a novel approach in the glaucoma treatment spectrum, offering a range of diverse procedures and devices aimed at reducing intraocular pressure (IOP). MIGS can be broadly classified into several categories: those that enhance trabecular outflow (Trabectome, iStent, Hydrus Microstent, Kahook Dual Blade, high frequency deep sclerotomy, and gonioscopy-assisted transluminal trabeculotomy), those that augment suprachoroidal outflow (CyPass Microstent and iStent Supra), those that target Schlemm's canal (TRAB360 and the OMNI Surgical System, Streamline, and Ab Interno Canaloplasty), and conjunctival bleb-forming procedures (EX-PRESS Glaucoma Filtration Device, Xen Gel Stent and PreserFlo MicroShunt). MIGS is considered to have a shorter surgical time and fewer severe complications when compared to traditional glaucoma surgeries such as trabeculectomy and glaucoma drainage device implantation (Ahmed, Baerveldt, and Molteno valves). This literature review comprehensively examines the distinct MIGS devices and procedures, their underlying mechanisms, and clinical outcomes, emphasizing the importance of evaluating the efficacy and complications of each approach individually. As the field of MIGS continues to evolve, it is crucial to prioritize high-quality, long-term studies to better understand the safety and effectiveness of these innovative interventions in glaucoma management.

Gonioscopy-Assisted Transluminal Trabeculotomy following Failed Glaucoma Surgery in Primary Congenital Glaucoma: One-Year Results

Purpose

To evaluate the one-year outcomes of gonioscopy-assisted transluminal trabeculotomy (GATT) in primary congenital glaucoma (PCG) with a history of prior glaucoma surgery.

Methods

A retrospective chart review was performed to identify all PCG patients ≤ 16 years who underwent GATT surgery at Cairo University Children's Hospital from January 2016 to March 2022. Pre- and postoperative intraocular pressure (IOP) and glaucoma medications were collected at 1, 3, 6, 9, 12, and last follow-up visits. Success was defined as IOP ≤ 21 mmHg without (complete) or with (qualified) glaucoma medications at the last follow-up.

Results

Seven eyes of 6 subjects were included in the study. The mean IOP was statistically significantly reduced from 25.7 ± 5.9 mmHg preoperatively to a mean IOP of 12 ± 1.5 mmHg (P = 0.001) at 12 months and 11.5 ± 1.2 mmHg (P = 0.001) at the last follow-up visit. Six eyes (85.7%) achieved complete success, and one eye (14.2%) achieved qualified success. No patients required further glaucoma procedures. No serious intra- or postoperative complications were identified.

Conclusions

Our early experience highlights that GATT can be performed as an alternative procedure before considering conjunctival or scleral glaucoma surgeries.