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Transcutaneous Auricular Vagus Nerve Stimulation in Dry Eye

Not Applicable
Recruiting
Conditions
Dry Eye Disease
Interventions
Device: Transcutaneous Auricular Vagus Nerve Stimulation
Drug: 0.1% sodium hyaluronate eye drop
Registration Number
NCT06696625
Lead Sponsor
Beijing Tongren Hospital
Brief Summary

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.

Detailed Description

Not available

Recruitment & Eligibility

Status
RECRUITING
Sex
All
Target Recruitment
256
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 & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
taVNS groupTranscutaneous Auricular Vagus Nerve StimulationtaVNS 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.
taVNS group0.1% sodium hyaluronate eye droptaVNS 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.
Control GroupTranscutaneous Auricular Vagus Nerve StimulationtaVNS 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.
Control Group0.1% sodium hyaluronate eye droptaVNS 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.
Primary Outcome Measures
NameTimeMethod
OSDIBaseline, month 1, 3, and 6

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).

Secondary Outcome Measures
NameTimeMethod
TBUTBaseline, month 1, 3, and 6

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.

SchirmerBaseline, month 1, 3, and 6

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.

CFSBaseline, month 1, 3, and 6

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.

DEQ-5Baseline, month 1, 3, and 6

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.

PHQ-9Baseline, month 1, 3, and 6

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.

SF-36Baseline, month 3, 6 and 12

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.

Trial Locations

Locations (1)

China Beijing TongRen Hospital, Capital Medical University Beijing, China

🇨🇳

Beijing, Beijing, China

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