PURPOSE:To evaluate the safety and efficacy of a trabecular microbypass stent combined with cataract surgery in patients with severe open-angle glaucoma. PATIENTS:The series included 59 eyes with severe primary open-angle glaucoma and severe visual field loss as defined by American Academy of Ophthalmology preferred practice pattern criteria. MATERIALS AND METHODS:Retrospective case series. Patients were implanted with 1 trabecular microbypass stent with concomitant cataract surgery. Primary outcome measures were intraocular pressure (IOP) and number of glaucoma medications. Safety measures included postoperative IOP pressure spikes ≥15 mm Hg or IOP<6 mm Hg at any time point, and the need for additional surgery. RESULTS:The mean preoperative IOP was 19.25±6.97 mm Hg. Postoperatively, the mean IOP was 14.38±3.63 mm Hg (P<0.01) at 12 months and 14.92±3.86 mm Hg (P<0.01) at 24 months. The mean number of glaucoma medications was 2.27±1.06 preoperatively and 1.63±1.17 (P<0.01) at 24 months postoperative, indicating a 28% reduction in medication use. In total, 4 (7%) eyes required additional surgery. In total, 5 eyes (8%) experienced IOP spikes ≥15 mm Hg, 14 (24%) eyes had IOP spikes ≥10 mm Hg. Overall 55% of eyes had a 20% IOP reduction after 24 months of surgery. Eyes with baseline IOP≤19 had a mean reduction of 2.24 mm Hg 36 months after surgery. CONCLUSIONS:Trabecular microbypass stent implantation during cataract surgery safely and effectively lowers IOP and medication use in patients with severe primary open-angle glaucoma.