Transcutaneous Auricular Vagus Nerve Stimulation in Dry Eye

Transcutaneous Auricular Vagus Nerve Stimulation in Dry Eye: a Randomized Clinical Trial

Objective: To evaluate the effect of transcutaneous auricular vagus nerve stimulation (taVNS) for the patients with dry eye disease.

Methods: The investigators enrolled 256 patients at Beijing Tongren Hospital. Patients completed questionnaires at baseline, 1 month, 3 months, and 6 months. OSDI score, TBUT, Schirmer I, CFS, SF36, DEQ5, and psychological status to evaluate the therapeutic effects. A difference of P < 0.05 was considered statistically significant.

Study Overview

• Status: Recruiting
• Conditions: Dry Eye Disease
• Intervention / Treatment: Device: Transcutaneous Auricular Vagus Nerve Stimulation; Drug: 0.1% sodium hyaluronate eye drop

• Study Type: Interventional
• Enrollment (Estimated): 256
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Dong Wu, Doctor; Phone Number: 8613810988682; Email: wudong0120@outlook.com

Study Locations

• China
  • Beijing
    • Beijing, Beijing, China, 100730
      • Recruiting
      • China Beijing TongRen Hospital, Capital Medical University Beijing, China
      • Contact: Dong Wu, Doctor; Phone Number: 8613810988682; Email: wudong0120@outlook.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Age >=18 and Age <=65.
2. complaint of DED symptoms for 6 months or longer at screening.
3. ocular surface disease index (OSDI) score of 25 or higher.
4. tear film breakup time (TFBUT) of 5 seconds or less.
5. Schirmer I test without anesthesia of 5 mm or more at 5 minutes.
6. tCFS score of 4 or higher.

Exclusion Criteria:

1. History systemic autoimmune diseases and ocular/periocular malignancy.
2. Clinically relevant slitlamp findings or abnormal lid anatomy.
3. Active ocular allergies and active infection.
4. Pregnant or lactating women.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: taVNS group; taVNS device (Elmmedicare, EC100, Shenzhen, China) was used to apply stimulation for patients. Stimulation parameters comprised an electrical current of 1 mA at a frequency of 20 Hz, with a waveform width of 1 ms. Repurposed off-the-shelf devices were utilized for this purpose, with the stimulator generating single square-wave pulses lasting 1 ms each. Enhancing conductivity was achieved by wiping the ear with tap water. The electrodes were placed on the cymba conchae and concha around the affected ear, which is the region of rich vagus nerve branch distribution.	Device: Transcutaneous Auricular Vagus Nerve Stimulation; taVNS device (Elmmedicare, EC100, Shenzhen, China) was used to apply stimulation for patients. Stimulation parameters comprised an electrical current of 1 mA at a frequency of 20 Hz, with a waveform width of 1 ms. Repurposed off-the-shelf devices were utilized for this purpose, with the stimulator generating single square-wave pulses lasting 1 ms each. Enhancing conductivity was achieved by wiping the ear with tap water. The electrodes were placed on the cymba conchae and concha around the affected ear, which is the region of rich vagus nerve branch distribution.; Drug: 0.1% sodium hyaluronate eye drop; Participants received 0.1% sodium hyaluronate eye drop (HYLO COMOD® eye drops, Ursapharm, Ltd., Germany).
Sham Comparator: Control Group; taVNS device (Elmmedicare, EC100, Shenzhen, China) was used to apply stimulation for patients. Stimulation parameters comprised an electrical current of 1 mA at a frequency of 20 Hz, with a waveform width of 1 ms. Repurposed off-the-shelf devices were utilized for this purpose, with the stimulator generating single square-wave pulses lasting 1 ms each. Enhancing conductivity was achieved by wiping the ear with tap water. The electrodes were placed on the cymba conchae and concha around the affected ear, which is the region of rich vagus nerve branch distribution. Patients in control group were applied using the same stimulator, stimulation parameters and same sessions. However, the electrodes were placed on the antihelix around the affected ear, which is the region of few vagus nerve branch distribution.	Device: Transcutaneous Auricular Vagus Nerve Stimulation; taVNS device (Elmmedicare, EC100, Shenzhen, China) was used to apply stimulation for patients. Stimulation parameters comprised an electrical current of 1 mA at a frequency of 20 Hz, with a waveform width of 1 ms. Repurposed off-the-shelf devices were utilized for this purpose, with the stimulator generating single square-wave pulses lasting 1 ms each. Enhancing conductivity was achieved by wiping the ear with tap water. The electrodes were placed on the cymba conchae and concha around the affected ear, which is the region of rich vagus nerve branch distribution.; Drug: 0.1% sodium hyaluronate eye drop; Participants received 0.1% sodium hyaluronate eye drop (HYLO COMOD® eye drops, Ursapharm, Ltd., Germany).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
OSDI	The Ocular Surface Disease Index (OSDI) includes 12 questions grouped by poor symptoms and visual disturbance (light sensitivity, eyes feel gritty, painful or sore eyes, blurred vision or poor vision); visual function/tasks (problems when reading, driving at night, working on a computer or watching TV); and environmental questions (problems in windy conditions, places/areas with low humidity or areas that are air conditioned). The scores range from 0 to 100. On the basis of the score, the patient's symptoms can be categorized as normal (0-12), mild dry eye (13-22), moderate dry eye (23-32), or severe dry eye (33-100).	Baseline, month 1, 3, and 6

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
TBUT	Tear breakup time (TBUT) is a clinical test used to assess for evaporative dry eye disease. To measure TBUT, fluorescein is instilled into the patient's tear film and the patient is asked not to blink while the tear film is observed under a broad beam of cobalt blue illumination. The TBUT is recorded as the number of seconds that elapse between the last blink and the appearance of the first dry spot in the tear film, as seen in this progression of these slit lamps' photos over time. A TBUT under 10 seconds is considered abnormal.	Baseline, month 1, 3, and 6
Schirmer	The Schirmer test is objectively used to measure tear secretion without anesthetized. A healthy eye should wet more than 10 mm of the standard filter strip in 5 minutes. The travel rate along the test strip is proportional to the tear production rate.	Baseline, month 1, 3, and 6
CFS	Corneal Fluorescein Staining (CFS) was measured using the National Eye Institute (NEI) scale, which ranges from 0 (no staining) to 3 (heavy staining) for each of the 5 areas of the cornea (inferior, superior, central, nasal, and temporal). The total score ranging from 0 to 15 is the sum of the 5 regions, with higher scores indicating greater symptom severity.	Baseline, month 1, 3, and 6
DEQ-5	The 5-Item Dry Eye Questionnaire (DEQ-5) contains five questions regarding the frequency and intensity of eye discomfort, eye dryness and watery eyes in the past month. The score ranges from 0 to 22, a score > 6 suggests dry eye, with higher scores indicating greater symptom severity.	Baseline, month 1, 3, and 6
PHQ-9	Depression was assessed with the 9-item Patient Health Questionnaire (PHQ). Patients were classified as having no depression (PHQ score: 0-4), mild (PHQ, score: 5-9), and moderate to severe depression (PHQ score: 10-27). Scores range from 0 to 27, with higher scores indicating greater symptom severity.	Baseline, month 1, 3, and 6
SF-36	36-Item Short Form Health Survey (SF36) measures quality of life on the basis of eight dimensions or concepts that are frequently used in health studies. These eight dimensions are estimated from eight subscales that examine physical functioning (SF36-PF), role functioning-physical (SF36-RP), bodily pain (SF36-BP), general health (SF36- GH), vitality (SF36-VT), social functioning (SF36-SF), role functioning-emotional (SF36-RE), mental health (SF36-MH) and reported health transition (SF36-HT). Item responses were ranging from 0 (best) to 100 (worst), with higher scores are equivalent to greater severity of better quality of life.	Baseline, month 3, 6 and 12

Collaborators and Investigators

• Sponsor: Beijing Tongren Hospital

Study record dates

Study Major Dates

• Study Start (Actual): July 1, 2021
• Primary Completion (Estimated): November 1, 2025
• Study Completion (Estimated): December 1, 2025

Study Registration Dates

• First Submitted: November 18, 2024
• First Submitted That Met QC Criteria: November 18, 2024
• First Posted (Estimated): November 20, 2024

Study Record Updates

• Last Update Posted (Estimated): November 20, 2024
• Last Update Submitted That Met QC Criteria: November 18, 2024
• Last Verified: October 1, 2024

More Information

Terms related to this study

• Keywords: RCT; Dry eye; taVNS
• Additional Relevant MeSH Terms: Corneal Diseases; Lacrimal Apparatus Diseases; Keratoconjunctivitis; Conjunctivitis; Conjunctival Diseases; Keratitis; Eye Diseases; Dry Eye Syndromes; Keratoconjunctivitis Sicca; Immunologic Factors; Physiological Effects of Drugs; Protective Agents; Adjuvants, Immunologic; Pharmaceutical Solutions; Viscosupplements; Hyaluronic Acid; Ophthalmic Solutions
• Other Study ID Numbers: DED_taVNS_2024

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No