Five-Year Outcomes Of A Schlemm's Canal Microstent With Cataract Surgery In Open Angle Glaucoma: The Canadian Experience

The HORIZON trial reported outcomes of Hydrus up to 5 years, whereas real-world outcomes for Hydrus are limited to 3 years postoperatively. This study aims to validate the findings of HORIZON trials in real-world settings and bridge the knowledge gap regarding long-term Hydrus outcomes beyond 3 years in patients with open-angle glaucoma (OAG).

Single-center retrospective consecutive case series.

This study included mild to moderate OAG patients who underwent Hydrus implantation with cataract surgery, with at least 5 years of follow-up data. Exclusion criteria: prior corneal transplant or retinal surgery. Primary endpoint: 5-year surgical success, defined as intraocular pressure (IOP) ≤18 mmHg on the same or fewer anti-glaucoma medications (AGMs), with no secondary glaucoma surgery. Secondary endpoints: 5-year changes in IOP, AGMs, vision, markers of disease stability (including visual field measures, retinal nerve fiber layer (RNFL) thickness, and ganglion cell- inner plexiform layer (GC-IPL) thickness), and safety.

Sixty-four eyes with an average age of 70.5±9.0 years were included. At 5 years postoperatively, surgical success was 68%, with eight eyes undergoing secondary glaucoma surgery. IOP decreased by 24% from 17.7±4.8 to 13.4±2.8 mmHg (p<0.001), and AGM use reduced by 28% from 2.9±1.2 to 2.1±1.2 medications (p<0.001). The postoperative improvement in BCVA was preserved (p<0.001). At 5 years postoperatively, the structural markers of disease stability, including CDR (0.71±0.13 pre; 0.72±0.10 post), RNFL (71.9±11.0 µm pre; 70.4±11.4 µm post), and GC-IPL thickness (63.1±8.4 µm pre; 61.4±8.4 µm post), remained stable (p>0.05). Postoperative adverse events were few and transient.

The 5-year results from this study show that Hydrus microstent with phacoemulsification is safe and effective in reducing the IOP and AGM use among patients with mild to moderate open-angle glaucoma and can slow down the disease progression evidenced by stability of structural parameters.