For a study, researchers sought to point to gonioscopy-assisted transluminal trabeculotomy (GATT) as a viable and safe surgical option for treating open-angle glaucoma (OAG). In their analysis, the only risk factor for failure was age. GATT 12-month clinical outcomes, safety profile, and success predictors in patients with OAG were reported. A retrospective study of patients (18 years and older) with medically uncontrolled OAG who underwent GATT alone or in conjunction with phacoemulsification (PHACO-GATT) between January 2018 and January 2020. At 12 months, success was defined as intraocular pressure (IOP) of less than 15 mm Hg, with an IOP reduction of at least 20% OR a reduction of at least 2 glaucoma medications compared to baseline. Success predictors and safety parameters were secondary outcomes. There were 73 eyes (GATT=38; PHACO-GATT=35) from 58 patients, with a mean age of 54.8, somewhat about 11.6 years. After a year of monitoring, the mean IOP dropped from 24.9, somewhat 8.5, to 12.1, somewhat about 2.1 mm Hg (P<0.001). The average number of glaucoma medications used decreased from 3.5, somewhat about 0.7, to 1.2, somewhat about 1.2 (P<0.001). At 12 months, the success rate was 87%, with no significant differences (P=0.330) between GATT (85%) and PHACO-GATT (91%) eyes. After adjusting for preoperative IOP and the number of glaucoma medications, age was the only factor associated with surgical success (hazard ratio=1.35; P=0.012). Patients over the age of 60 had a significantly higher risk of failure (hazard ratio=10.96; P=0.026) than those under 60. Transient hyphema (39%; median duration, 5 days) was the most common postoperative complication. There were no sight-threatening adverse events reported. In OAG, GATT was effective and safe for lowering IOP with or without cataract extraction. Patients aged 60 and up had a higher risk of failure than those younger.