Intranasal Neurostimulator Induces Morphologial Changes in Meibomian GLands in Patients with Dry Eye Disease

Abstract

Purpose : The Intranasal Tear Neurostimulator (ITN) delivers a small electrical current to sensory neurons of the nasal cavity that stimulate the nasolacrimal reflex to induce tear production. Most patents with dry eye (DE) suffer from decreased tear break-up time with varying degrees of meibomian gland (MG) dysfunction. Meibum expression is typically achieved though coordinated muscular activity of the orbicularis and Riolan’s muscles, both of which are innervated by the cranial nerve CN-VII. This study explored whether MG morphology was altered following use of the ITN.

Methods : Twelve DE subjects were enrolled in a single-center, single-arm study. Anterior segment optical coherence tomography (AS-OCT) meibography was performed on the lower eyelids of each patient before and after approximately 3 minutes of ITN stimulation. Central MGs clearly shown in both sets of AS-OCT images were selected for analysis. The same MGs were selected before and after stimulation. In the selected images three or four glands were analyzed. The MGs were selected according to the accuracy and quality from the image. Two masked observers then analyzed images using ImageJ™ software. The area and perimeter of selected MGs were quantified, and the effect of ITN on MGs was determined by morphological changes after stimulation. 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 pre- and post-stimulation MG areas were 2,184.76±135.51µm² and 1,933.2±114.82mm², respectively. The mean change in area, 251.56±20.69 µm², representing a 11.6% reduction following use of the ITN, was statistically significant (p<0.001). Mean pre- and post-stimulation MG perimeters were 222.2±10.14 µm and 235.9±10.95mm, respectively. The mean change in perimeter, 13.7±0.81 µm, representing a 5.81% reduction following use of the ITN, was statistically significant (p<0.012). The images after use of the INT showed an increase in brightness at the conjunctival surface, and hyporeflective areas at orifices of the MGs suggesting release of meibum.

Conclusions : In addition to lacrimal gland stimulation, use of the ITN has a significant effect on MG morphology. Post-ITN use, MGs were measurably reduced in area and perimeter, suggesting release of meibum.

This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.