Abstract
Purpose :
Studies have demonstrated that intranasal stimulation via use of the Intranasal Tear Neurostimulator (ITN)results in a statistically significant increase in tear production measured by the Schirmer’s test. While this test is a clinically relevant and accepted measure, the strip itself absorbs a substantial percentage of the resident and secreted tear volume, confounding repeat measurements over a discrete time frame. Tear meniscus height (TMH) as captured by optical coherence tomography (OCT) has been established as a non-invasive and accurate measure of tear quantity and production. The objective of this study was to compare the change in TMH between pre- and post-ITN vs extranasal (control) applications.
Methods :
25 dry eye subjects were enrolled in acrossover,4-visit study consisting of one screening examination (V1) and 3 application visits (V2-V4). At V2, subjects received two applications of approximately 3 minutes each (ITN or extranasal control) in randomized order, with tear production measured via the unanesthetized Schirmer’s test. At V3 and V4, subjects received a single treatment (ITN or extranasal control) in randomized order with TMH captured prior to and immediately following ~2 minutes of application (Heidelberg Spectralis).All data are shown as Mean±SD. Mean data were compared using a paired t-test. P-values <0.05 were considered statistically significant.
Results :
Mean tear production at V2 was 25.9±9.8 mm and 5.8±4.9 mm post-stimulation with the ITN and extranasal control, respectively. The mean paired difference, 20.1±9.2 mm, was statistically significant (p<0.0001). Consistent with these results, mean change in TMH (post- minus pre-stimulation), for the INT and the extranasal control application was 449±543 µm and 56±198 µm, respectively. The mean paired difference in TMH change between the INT and extranasal control, 394±520 µm, was also statistically significant (p=0.002).
Conclusions :
Use of the ITN results in a statistically significant increase in acute tear production in dry eye subjects as measured by both the Schirmer’s test and TMH captured by OCT. Assessment of TMH provides a non-invasive option for future studies aimed at further characterizing tear production stimulated by ITN.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.