Clinical outcomes of Hydrus Microstent implantation for open-angle glaucoma: Results from a large academic center.

Purpose: To assess the clinical outcomes of Hydrus Microstent implantation with cataract extraction for the treatment of open angle glaucoma (OAG) over a maximum of 4 years.

Design: Retrospective, single-center, single-arm, longitudinal cohort study.

Subjects: 308 patients (464 eyes) with OAG who underwent Hydrus Microstent implantation with cataract extraction between February 2019 and December 2021, followed for a median (interquartile range, IQR) of 2.0 (1.3, 2.8) years.

Methods: Medical records were reviewed to collect demographic and clinical data. After assessment for Gaussian distribution, mean and standard deviation (SD) or median and IQR were calculated. Change from baseline was calculated with mixed-effects models and expressed as mean change and standard error (SE).

Main outcome measures: 1) Intraocular pressure (IOP); 2) number of glaucoma medications; 3) need for additional glaucoma procedures; and 4) rate of glaucoma progression, calculated using mean deviation (MD) from standard automated perimetry and optical coherence tomography peripapillary retinal nerve fiber layer (RFNL) thickness.

Results: Among 308 patients, 60.7% (n=187) were White and 50.6% (n=156) were female. The median (IQR) age was 74 (68, 78) years. Most eyes had mild (63.8%) or moderate (23.9%) OAG. Of 464 eyes, 99 (21.4%) had undergone prior procedures for glaucoma. At baseline, the mean (±SD) IOP was 16.0±3.7 mmHg while taking 1.9±1.1 glaucoma medications. After Hydrus implantation, a sustained reduction was observed in mean IOP [mean change±SE]: -1.9±0.3 at 6 months (p<0.0001), -1.2±0.2 at 1 year (p<0.0001), -1.2±0.2 at 2 years (p<0.0001), -1.6±0.3 at 3 years (p<0.0001) and -1.2±0.7 at 4 years (p=0.02)]. Glaucoma medications were reduced by 1.2±0.1 at 6 months (p<0.0001), 1.1±0.1 at 1 year (p<0.0001), 1.0±0.1 at 2 years (p<0.0001), 0.9±0.1 at 3 years (p<0.0001) and 0.5±0.2 at 4 years (p=0.03). Only 14 eyes (3.2%) required additional glaucoma procedures. Compared to the lookback period, the rates of visual field MD and RNFL loss decreased in the postoperative period by 0.18±0.08 dB/year (-0.18±0.02 vs 0.004±0.08 dB/year, p=0.02) and 0.51±0.29 μm/year (-0.47±0.12 vs 0.04±0.21 μm/year, p=0.07), respectively.

Conclusions: In this non-trial setting, cataract surgery with Hydrus Microstent implantation was associated with sustained reductions in IOP, glaucoma medication burden, and disease progression rate.