Purpose: To determine outcomes of minimally invasive glaucoma surgeries (MIGS) and traditional incisional glaucoma surgeries (TIGS)—trabeculectomy and glaucoma drainage devices—in IRIS® Registry (Intelligent Research in Sight). Design: Retrospective cohort study. Subjects: Age ≥18 years with open-angle glaucoma who underwent MIGS or TIGS. Methods: We identified patients in the IRIS Registry who had MIGS or TIGS between 2014-2018 and at least 1-year of follow-up. Inclusionary criteria included diagnosis of open-angle. Main Outcome Measures: Co-primary outcomes included success rates at 1 year, defined as intraocular pressure (IOP) ≤14, ≤18, or ≤21 mmHg or IOP reduction ≥20%; IOP not ≤5 mmHg at 2 consecutive visits; no additional glaucoma surgery; and no loss of light perception. Additional outcomes included mean IOP and medications at 1 year. Results: After the inclusion/exclusion criteria, there were 56,915 MIGS eyes and 17,983 TIGS eyes (total 74,898 eyes from 56,136 patients). MIGS success rates at 1 year were low using targets of IOP ≤14 mmHg (43%) or reduction ≥20% (25%) and were higher with ≤18 mmHg (80%) and ≤21 mmHg (91%). Although TIGS had greater success at achieving IOP ≤14 mmHg (54%) and reduction ≥20% (59%), they were significantly lower than MIGS with ≤18 mmHg (77%) and ≤21 mmHg (85%). Adjusted IOPs for MIGS were 16.49 (95% CI 16.27, 16.71) pre-treatment and 14.84 (95% CI 14.65, 15.03) at 1 year. For TIGS, adjusted IOPs went from 23.54 (95% CI 22.91, 24.17) to 14.00 (95%CI: 13.62, 14.37). Adjusted medication changes were from 2.06 (95% CI 1.99, 2.12) to 2.19 (95% CI 2.11, 2.26) and 3.38 (95% CI 3.27, 3.48) to 2.78 (95% CI 2.67, 2.88) for MIGS and TIGS, respectively. Rates of severe complications (endophthalmitis, suprachoroidal hemorrhage, hypotony/flat anterior chamber, retinal detachment) were substantially lower in the MIGS group (P<0.05 for all). Conclusions: MIGS success in achieving low IOPs (≤14) or reduction ≥20% was low but higher with cutoffs of ≤18 and ≤21. With TIGS, there was good success at all the cutoff values (>50%). Both groups had significant reductions in IOP, with TIGS having a significant reduction in medications at 1 year. MIGS had less severe complications.