A Prospective Randomized Trial Comparing Hydrus and iStent Microinvasive Glaucoma Surgery Implants for Standalone Treatment of Open-Angle Glaucoma

Purpose

To compare the efficacy of different microinvasive glaucoma surgery (MIGS) devices for reducing intraocular pressure (IOP) and medications in open-angle glaucoma (OAG).

Design

Prospective, multicenter, randomized clinical trial.

Participants

One hundred fifty-two eyes from 152 patients aged 45 to 84 years with OAG, Shaffer angle grade III–IV, best-corrected visual acuity (BCVA) 20/30 or better, and IOP 23 to 39 mmHg after washout of all hypotensive medications. Eyes with secondary glaucoma other than pseudoexfoliative or pigmentary glaucoma, angle closure, previous incisional glaucoma surgery, or any significant ocular pathology other than glaucoma were excluded.

Intervention

Study eyes were randomized 1:1 to standalone MIGS consisting of either 1 Hydrus Microstent (Ivantis, Inc, Irvine, CA) or 2 iStent Trabecular Micro Bypass devices (Glaukos Inc, San Clemente, CA). Follow-up was performed 1 day, 1 week, and 1, 3, 6, and 12 months postoperatively.

Main Outcome Measures

Within-group and between-group differences in IOP and medications at 12 months and complete surgical success defined as freedom from repeat glaucoma surgery, IOP 18 mmHg or less, and no glaucoma medications. Safety measures included the frequency of surgical complications, changes in visual acuity, slit-lamp findings, and adverse events.

Results

Study groups were well matched for baseline demographics, glaucoma status, medication use, and baseline IOP. Twelve-month follow-up was completed in 148 of 152 randomized subjects (97.3%). At 12 months, the Hydrus had a greater rate of complete surgical success (P < 0.001) and reduced medication use (difference = −0.6 medications, P = 0.004). More Hydrus subjects were medication free at 12 months (difference = 22.6% P = 0.0057). Secondary glaucoma surgery was performed in 2 eyes in the 2-iStent group (3.9%) and in none of the Hydrus eyes. Two eyes in the Hydrus group and 1 in the 2-iStent group had BCVA loss of ≥2 lines.

Conclusion

Standalone MIGS in OAG with the Hydrus resulted in a higher surgical success rate and fewer medications compared with the 2-iStent procedure. The 2 MIGS devices have similar safety profiles.