Structural and Metabolic Imaging After Short-term Use of the Balance Goggles System in Glaucoma Patients: A Pilot Study

Precis: Short-term use of the Balance Goggles System (BGS) in glaucoma patients was not associated with the observable changes in conventional ocular coherence tomography (OCT) imaging, but metabolic imaging using peripapillary flavoprotein fluorescence (FPF) may represent a useful adjuctive investigation. Objective: To determine whether the intraocular pressure (IOP)-lowering effects of the BGS are accompanied by changes in retinal thickness measured by OCT, retinal vascular density measured by ocular coherence tomography-angiography (OCTA), or novel peripapillary metabolic profiling using FPF measured by a fundus camera. Design: Prospective comparative case-series. Subjects: Eight eyes from 8 patients with open angle glaucoma ranging from mild to severe. Methods: In this prospective, single-center, open-label, nonrandomized, and single-arm study patients received a baseline evaluation including retinal imaging, then 1 hour of negative pressure application through the BGS, followed by repeat retinal imaging. Participants then used the BGS at home for 1 month and underwent a repeat evaluation at the conclusion of the trial. Main Outcome Measures: Changes in nerve fiber layer thickness, OCTA vascular parameters, and FPF scores. Results: Mean baseline IOP was 18.0 +/- 3.1 mmHg and there was no significant change in IOP at follow-up. At 1 month compared with baseline, there was a statistically significant improvement in FPF optic nerve head rim scores (12.7 +/- 11.6 to 10.5 +/- 7.5; P=0.04). In addition, there was a trend toward an increase in retinal nerve fiber layer thickness after 1 month (69.5 +/- 14.2 to 72.0 +/- 13.7; P=0.1), but there were no statistically significant differences observable with any of the OCTA vascular parameters either at 1 hour or after 1 month. Conclusions: There were no significant changes observable using conventional OCT imaging after short-term use of the BGS, although metabolic imaging using FPF may be a useful potential biomarker to complement existing investigations. Additional studies are warranted to further investigate these changes.