Optical Quality and Tear Film Analysis Before and After Intranasal Stimulation in Patients with Dry Eye Syndrome

PURPOSE: To evaluate the optical quality and tear film quality in patients with dry eye syndrome (DES) before and after using an intranasal neurostimulation device to stimulate tear production. METHODS: Cross-sectional review of 33 eyes in 21 patients with DES who underwent optical quality and tear film analysis as part of their routine dry eye evaluation pre- and post-neurostimulation trial in office. Optical quality was assessed by measuring the objective scattering index (OSI) and modulation transfer function (MTF). The time to blink and mean tear film OSI were used to analyze the tear film. RESULTS: Optical quality after the use of the intranasal neurostimulator improved with an average decrease (improvement) in OSI of 0.30±0.68 (P=0.015) and an average increase (improvement) in MTF of 2.12±9.2 (P=0.15). Pre-intranasal neurostimulation OSI had a positive correlation with age (Spearman’s rho 0.60, p < 0.001), while MTF had a negative correlation (Spearman’s rho −0.38, p = 0.03). Pre-intranasal neurostimulation OSI had a negative correlation with MTF (Spearman’s rho −0.85, p < 0.001) and a positive correlation with tear film mean OSI (Spearman’s rho 0.85, p <0.001). CONCLUSION: The optical quality of patients with DES is improved with the use of intranasal neurostimulation for tear production, and there was a trend towards improved MTF though not statistically significant. Future studies are needed to follow patients longitudinally.