Outcomes of Hydrus Microstent with Cataract Surgery in Asian and Non-Asian Eyes with Normal Tension Glaucoma

To evaluate the efficacy and safety of the Hydrus Microstent in conjunction with cataract surgery in patients with normal tension glaucoma (NTG) with minimum 12-month follow-up.

Retrospective cohort study.

Normal tension glaucoma eyes having Hydrus with cataract surgery and cataract-only controls.

Glaucoma was staged by the Hodapp-Parrish-Anderson criteria. Generalized estimating equations were used to account for intraocular correlation in regression analyses.

The primary outcome was medication reduction from baseline at 1 year. Secondary outcomes were medication reduction in subsequent years, mean intraocular pressure (IOP) change from baseline, proportion of eyes meeting IOP targets, and percentage of eyes requiring secondary surgical interventions (SSI) at yearly time points.

Sixty-four eyes of 40 patients undergoing Hydrus Microstent and cataract surgery were included in the analysis, of which 32 eyes were from Asian patients. Thirty-nine eyes of 25 patients were used as cataract-only controls. Glaucoma severity was mild (37.5%), moderate (40.6%) and severe (21.9%) in treated eyes. The median follow-up available was 2.5 years (range: 1-5 years). Baseline IOP was 13.83 ± 2.93 mmHg on 2.11 ± 1.04 medication classes in treated eyes. At year 1, there was a mean reduction of medication classes by 1.25 ± 0.84 (P < 0.0010) and IOP by 0.89 ± 2.61 mmHg (P = 0.02). Medication class reduction remained significant through year 4 and IOP reduction through year 3. Compared to controls, treated eyes had significant differences in mean medication change (-1.25 vs. -0.03 at year 1, P < 0.001) and percentage of eyes with medication reduction (85.9% vs. 5.3% at year 1, P < 0.001), which were sustained through at least year 4. There were no significant differences in medication reduction and IOP observed between treated Asian and non-Asian eyes at any time point. In treated eyes, IOP was 16 mmHg or less on same or fewer medications in more than 90% (range: 90.6%-100%) of eyes at all time points and medication-free in more than 31% (range: 31.3%-54.5%) at all time points. No SSI occurred during the study period.

Hydrus Microstent was safe and effective in all NTG eyes with a significant, sustained reduction in medication use through at least 4 years of follow-up.

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