Two Second-Generation Trabecular Micro-bypass Stents to Treat Glaucoma Subjects on One Hypotensive Medication

INCLUSION CRITERIA: Screening Exam Inclusion Criteria: * Phakic patients or pseudophakic patients with posterior chamber intraocular lenses (PC-IOLs). * Primary open-angle glaucoma (including pigmentary or pseudoexfoliative). * Cup-to-disc ratio ≤ 0.9. * Visual field defects, or nerve abnormality characteristic of glaucoma. * One topical hypotensive medication at time of screening exam. * Intraocular pressure (IOP) \> 18 mmHg and ≤ 30 mmHg (medicated) at screening exam. * Study eye BCVA 20/100 or better. * Normal angle anatomy as determined by gonioscopy. * Absence of peripheral anterior synechia (PAS), rubeosis or other angle abnormalities that could impair proper placement of stent. Baseline Exam Inclusion Criteria: * Subject has completed appropriate medication washout. * Mean IOP \> 22 mmHg and ≤ 38 mmHg after anti-glaucoma medication washout period. EXCLUSION CRITERIA: Screening Exam Exclusion Criteria: * Aphakic patients or pseudophakic patients with anterior chamber IOLs (AC-IOLs). * Prior stent implantations (study eye). * Traumatic, uveitic, neovascular, or angle-closure glaucoma; or glaucoma associated with vascular disorders. * Functionally significant visual field loss, including severe nerve fiber bundle defects such as Bjerrum scotoma. * Prior incisional glaucoma surgery. * Prior SLT within 90 days prior to screening. * Prior ALT. * Iridectomy or laser iridotomy. * Ineligibility for ocular hypotensive medication washout period as determined by the investigator such as: visual field status would be placed at risk by washout period, or unmedicated IOP after washout period would be expected to exceed upper limit of ≥ 38 mmHg. * Any active corneal inflammation or edema (e.g., keratitis, keratoconjunctivitis, keratouveitis). * Clinically significant corneal dystrophy (e.g., bullous keratopathy, Fuch's dystrophy); any guttata. * Corneal surgery (prior or anticipated) of any type (including LASIK, LASEK, PRK, etc.) that may interfere with IOP measurement reliability. * Corneal opacities or disorders that would inhibit visualization of the nasal angle. * Congenital or traumatic cataract. * Retinal or optic nerve disorders, either degenerative or evolutive, that are not associated with the existing glaucoma condition. * Elevated episcleral venous pressure such as associated with: active thyroid orbitopathy, cavernous sinus fistula, Sturge-Weber syndrome, orbital tumors, orbital congestive disease. * Clinically significant sequelae from trauma (e.g., chemical burns, blunt trauma, etc.). * Chronic ocular inflammatory disease or presence of active ocular inflammation (e.g., uveitis, iritis, iridocyclitis, retinitis). * Pregnant or nursing women. Baseline Exam Exclusion Criteria: * Subject did not complete medication washout. * Mean IOP \< 22 mmHg or \> 38 mmHg after anti-glaucoma medication washout. * Subject did not have a 3mmHg IOP increase over screening mean diurnal IOP.