Negative Pressure Application by the Ocular Pressure Adjusting Pump to Lower IOP in Normal-Tension Glaucoma: Hercules Study.

Abstract

Purpose: To evaluate the safety and IOP-lowering efficacy of the Ocular Pressure Adjusting Pump in subjects with normal-tension glaucoma.

Design: Prospective, multi-center, masked, randomized, fellow-eye controlled trial.

Subjects, participants and/or controls: Subjects with normal-tension glaucoma (NTG) with an IOP ≥12 mmHg and ≤21 mmHg were enrolled. One eye of each subject was randomized to receive negative pressure application; the fellow eye served as a control.

Methods: Subjects wore the device overnight for 1 year and the applied negative pressure was programmed by subtracting a reference IOP of 6 mmHg from the baseline IOP.

Main outcome measures: The primary effectiveness endpoint was the proportion of eyes achieving an IOP reduction ≥20% at Week 52 during the day. The secondary endpoint was the proportion of eyes achieving a nocturnal IOP reduction ≥20% at Week 52. Exploratory endpoints included mean IOP reduction in clinic and in the sleep lab.

Results: 186 eyes were randomized across 11 sites. 120 eyes successfully completed all visits across 52 weeks without protocol deviations. At Week 52, 88.3% (n=53) of study eyes versus 1.7% (n=1) of control eyes met the primary endpoint. For the secondary endpoint, 96.7% (n=58) of study eyes versus 5.0% (n=3) met the endpoint. For exploratory IOP analysis, the mean nocturnal IOP reduction at Week 52 was 8.0 mmHg (39.1%) from a baseline of 20.4 ± 2.5 mmHg to 12.4 ± 2.7 mmHg. There were no serious adverse events (AEs). The most commonly reported adverse events were lid (11.8% study, 1.1% control) and periorbital edema (12.9%, 1.1%).

Conclusions: The Ocular Pressure Adjusting Pump safely and effectively lowers both daytime and nocturnal IOP in patients with normal-tension glaucoma.