Purpose <p>To compare the efficacy and safety of 360º suture gonioscopy-assisted transluminal trabeculotomy (GATT) and 180º GATT (hemi-GATT) combined with cataract surgery in patients with open-angle glaucoma (OAG).</p> Methods <p>This single-center retrospective study included patients with OAG treated by GATT or hemi-GATT combined with phacoemulsification with at least six months of follow-up. Outcome measures included change in intraocular pressure (IOP), best-corrected visual acuity (BCVA), and number of glaucoma medications (NGM) used. Success was defined as IOP &lt; 18 mmHg with complete reduction of NGM, or IOP &lt; Pre-Op IOP with complete reduction of NGM, or more than 20% IOP reduction with the same or a smaller number of NGM.</p> Results <p>Data from 35 patients (mean age = 76 years) and 38 treated eyes were included in this study. The procedural success rate with GATT and hemi-GATT was 94% and 91%, respectively. Average IOP reduced from 17.0 ± 4.8 to 12.9 ± 2.7 mmHg in GATT (Δ=-4.2 mmHg, <i>p</i> = 0.005) and from 17.8 ± 4.9 to 13.8 ± 3.12 mmHg in hemi-GATT (Δ=-4 mmHg, <i>p</i> = 0.002) groups after six months. Average NGM was reduced from 3.5 to 0.3 medications in GATT (Δ=-3.2, <i>p</i> &lt; 0.0001) and from 2.5 to 0.5 medications in hemi-GATT (Δ=-2, <i>p</i> &lt; 0.0001) after six months. There were no serious adverse events in the two study groups.</p> Conclusion <p>GATT and hemi-GATT with concomitant phacoemulsification cataract surgery are equally safe and effective procedures for decreasing IOP and NGM.</p>