Symptom improvement in dry eye subjects following intranasal tear neurostimulation: Results of two studies utilizing a controlled adverse environment.

Purpose: To evaluate the safety and effectiveness of the intranasal tear neurostimulator (ITN) in improving dry eye symptoms assessed in a controlled adverse environment (CAE®).
Methods: Study 1: Multicenter, subject-masked, randomized-sequence, crossover design. Single intranasal (active) and extranasal (control) ITN administration during CAE exposure. Study 2: Single-arm, open-label design. Intranasal ITN administration ≥2 times/day for 45 days, CAE assessment at days 0 and 45. In both studies, upon CAE entry, and every 5 min thereafter, subjects assessed eye dryness score (visual analog scale, 0-100 mm; EDS-VAS), and ocular discomfort score (ODS; Ora Calibra™, 0-4), for ≈2 h. Study 1: when ODS was ≥3 at 2 consecutive timepoints, subjects applied ITN intranasally or extranasally for ≈3 min, and again when achieving the same ODS criteria in randomized sequence. Study 2: days 0 and 45, ITN was applied for ≈3 min employing the same ODS criteria as Study 1.
Results: Study 1: Significantly greater pre- to post-application reductions in mean [SEM] EDS (-16.5 [1.7] vs -3.1 [1.7], P < 0.0001) and ODS (-0.93 [0.08] vs -0.34 [0.08], P < 0.0001; n = 143) with intranasal vs extranasal stimulation. Study 2: On day 0 (n = 52) and day 45 (n = 48), significant pre- to post-application reductions in mean [SEM] EDS (-15.9 [2.7] and -15.2 [2.4]; P < 0.0001), and ODS (-1.3 [0.2] and -1.3 [0.1]; P < 0.0001). Few device-related adverse events were reported, none serious.
Conclusions: Acute symptom relief is significant with the ITN and remains undiminished after daily use.
(Copyright © 2019 The Authors. Published by Elsevier Inc. All rights reserved.)