Three-Year Outcomes of a Schlemm Canal Microstent (Hydrus Microstent) with Concomitant Phacoemulsification in Open-Angle Glaucoma

Abstract

HORIZON trials have reported the medium- and long-term outcomes of the Hydrus microstent. However, outside of randomized clinical trials, outcomes beyond 24 months have not been previously reported. Here, we examine the 3-year outcomes of the Hydrus microstent with cataract surgery outside of a randomized clinical trial setting. Single-surgeon consecutive case series. Glaucomatous eyes that underwent implantation of a Hydrus microstent with concomitant cataract surgery at a single ophthalmology center in Montreal, Canada. Success was defined according to the absence of specific failure criteria: (A) glaucoma reoperation; (B) selective laser trabeculoplasty; (C) intraocular pressure (IOP) < 5 mmHg, > 18 mmHg, or increase in the number of antiglaucoma medications (AGMs) used (after the first postoperative month), or loss of light perception due to glaucoma; (D) aggregation of criteria A-C. Predictors of treatment failure and postoperative changes in IOP and AGM use were assessed. Safety included best-corrected visual acuity (BCVA), cup-to-disc ratio (CDR), retinal nerve fiber layer (RNFL) thickness, ganglion cell inner plexiform layer (GC-IPL) thickness, visual field mean deviation (VF-MD) and pattern standard deviation (VF-PSD), and adverse events. Surgical success, predictors of treatment failure, postoperative changes in IOP and AGM use, and structural and functional markers of disease stability. One hundred six eyes were included. The 3-year surgical success according to Criteria A to D was 86%, 83%, 91%, and 67%, respectively. Intraocular pressure decreased by 26.5% from 18.9 ± 4.8 to 13.9 ± 2.3 mmHg (P < 0.001) and AGM use reduced by 33% from 3.0 ± 1.2 to 2.0 ± 1.2 medications (P < 0.001). The postoperative improvement in BCVA was preserved (P < 0.001). The structural and functional markers of disease stability, including CDR, RNFL, and GC-IPL thickness, as well as VF-MD and VF-PSD, remained stable (P > 0.05). Postoperative adverse events were few and transient. The 36-month results from this study show that the Hydrus microstent with phacoemulsification is safe and effective in reducing the IOP and AGM among patients with mild to severe open-angle glaucoma and can slow down the disease progression by preserving both structural and functional parameters. Proprietary or commercial disclosure may be found after the references.