Clinical Efficacy of Electrical Auricular Transcutaneous Stimulation for Dry Eye: A sham-controlled, Randomized Trial

Abstract

Background: This study aimed to evaluate the clinical efficacy of low-frequency ear transcutaneous stimulation (TS) for improving ocular symptoms and signs in patients with dry eye disease (DED). The primary outcome was the Ocular Surface Disease Index (OSDI) score difference between TS and sham groups, while secondary outcomes included tear break-up time (TBUT), Schirmer's test (SM tube), and corneal staining (National Eye Institute [NEI] score).

Methods: Patients with a tear film break-up time (TBUT) < 5 s and tear volume by Schirmer's test < 5 mm, along with ocular symptoms, were randomized into a TS treatment group (n=25) and a sham group (n=24). The TS treatment device was applied bilaterally twice daily for 8 weeks, with each session lasting 30 minutes. The ocular surface disease index (OSDI) questionnaire score, corneal and conjunctival stain score (National Eye Institute [NEI]), TBUT, and tear secretion volume (SM tube) were analyzed at baseline and 4 and 8 weeks after treatment.

Results: The sham group showed no significant changes in any parameters at 4 and 8 weeks. The TS group demonstrated significant improvements in NEI score, TBUT, and SM tube values at both 4 and 8 weeks compared to the sham group (p= 0.002, 0.001, 0.017 at 4 weeks; p= 0.001, 0.001, and 0.001 at 8 weeks). No significant difference in OSDI was found between groups at 4 weeks (p= 0.061), but at 8 weeks, the TS group showed a significantly greater improvement (p= 0.018).

Conclusion: The low-frequency ear TS device significantly improved DED symptoms and objective measures compared to the sham group. These findings support the potential of TS as a novel treatment option for DED.

Keywords: Dry eye disease; Electrical transcutaneous stimulation; Ocular surface disease index.