Purpose: To assess (1) safety and efficacy of MicroPulse transscleral laser therapy (TLT) for primary open-angle glaucoma (POAG) and (2) the influence of prior incisional glaucoma surgery, lens status, and visual acuity on TLT outcomes. Setting: Institutional. Design: Retrospective cohort study. Materials and methods: Study population: Included were POAG patients aged 18–85 with TLT between 1st January 2020 and 15th July 2023; excluded were patients with secondary glaucomas, inflammatory disease, or pregnancy. Intervention: MicroPulse TLT was performed on one or both eyes with an Iridex Cyclo G6 Laser with settings: 31.3% duty cycle, 2,500 mW, 20 second/sweep/hemisphere, four to six sweeps. The revised MP3 probe was used. Outcome measures: Pre- and postop: intraocular pressure (IOP), best-corrected visual acuity (BCVA), glaucoma meds, subsequent procedures, cystoid macular edema (CME). Analysis: Kaplan–Meier (KM) survival statistics starting one month postop with dropout parameters: hypotony, subsequent glaucoma procedure, glaucoma medications >baseline, IOP >21 mm Hg, IOP reduction <20%, or loss of LP vision. Results: Thirty-three eyes were included. Mean KM survival (months) was: all eyes 8.4 ± 1.1; phakia 6.2 ± 0.8; pseudophakia 10.8 ± 2.4; aphakia 9.2 ± 1.8; prior tube shunt 10.2 ± 1.8; no filtration 6.8 ± 0.8. IOP and glaucoma medications remained at or below baseline at all postoperative timepoints. There were no significant changes in BCVA for patients with good baseline vision (>20/40), and no patients developed hypotony, persistent inflammation, or lost LP vision. Factors limiting success were time from the procedure and number of sweeps. Conclusion: Survival was better in pseudophakic eyes and after tube shunt surgery. Six sweeps resulted in higher success compared to four. There were no significant cases of postop CME. The procedure did not negatively impact vision in eyes with good baseline vision.