Initial Clinical Experience With the CyPass Micro-Stent

Abstract

To evaluate safety and clinical outcomes of a novel supraciliary device, the CyPass Micro-Stent, for surgical treatment of open-angle glaucoma when implanted in conjunction with cataract surgery. Subjects (n=142) with open-angle glaucoma and cataract underwent combined phacoemulsification, with intraocular lens insertion, and microstent implantation into the supraciliary space of study eyes (n=167). Two analysis cohorts were prespecified based upon medicated baseline intraocular pressure (IOP): ≥21 mm Hg (cohort 1, n=65) or <21 mm Hg (cohort 2, n=102). Glaucoma medications were discontinued or tapered at surgery, and restarted at investigator discretion. The main postoperative outcome measures were adverse events, IOP changes, and number of IOP-lowering medications. Mean±SD follow-up was 294±121 days. No major intraoperative or postoperative complications occurred. Preoperative baseline mean IOP was 20.2±6.0 mm Hg and mean number of IOP-lowering medications was 2.0±1.1. Cohort 1 showed a 35% decrease in mean IOP and a 49% reduction in mean glaucoma medication usage; cohort 2 demonstrated a 75% reduction in mean medication usage while maintaining mean IOP<21 mm Hg. For all eyes, mean IOP at 12 months was 15.9±3.1 mm Hg (14% reduction from baseline). Early and late postoperative IOP elevation occurred in 1.2% and 1.8% of eyes, respectively. Two subjects developed mild transient hyphema, and none exhibited prolonged inflammation, persistent hypotony, or hypotony maculopathy. CyPass Micro-Stent implantation, combined with cataract surgery, resulted in minimal complications and reduced IOP and IOP-lowering medication use at 12 months postoperatively.