Pilot Study of TENS for Ocular Pain

Study Overview
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Brief Summary
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Approximately 20% of Veterans have a diagnosis of dry eye (DE) syndrome which is often accompanied by ocular pain that significantly impacts activities of daily living. Currently very few treatments are available for chronic ocular pain, likely because the mechanisms underlying this type of pain have only recently begun to be studied. New treatments that target the neuropathic mechanisms contributing to this type of pain are needed. The proposed research provides a crucial step in addressing the lack of treatments for neuropathic ocular pain by validating the methodology needed to support a randomized controlled trial of transcutaneous electrical nerve stimulation (TENS). TENS is a non-pharmacologic, non-addictive, non-invasive treatment that has been shown to be effective in other chronic pain conditions. The present pilot study aims to address the need for preliminary support of safety and efficacy of TENS for ocular pain, t to advance the study of new treatments for the long-term relief of chronic ocular pain and its impact on health.

Official Title
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A Pilot Study of the Safety and Feasibility of Transcutaneous Electrical Nerve Stimulation (TENS) for Chronic Ocular Pain

Conditions
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Eye Pain

Intervention / Treatment
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* Device: Active Cefaly Dual (R)
* Device: Sham Cefaly Dual (R)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: male or female all races and ethnicities at least 18 years of age persistent eye pain for at least 6 months average eye pain intensity of 4 or more on a 0-10 numerical rating scale on a stable medication regimen for at least the past 3 months na�ve to TENS use for orofacial conditions eye pain having neuropathic-like characteristics Exclusion Criteria: presence of ocular diseases that are the likely cause of pain (i.e., corneal and conjunctival scarring, corneal edema, uveitis, iris transillumination defects, etc.) contraindication to TENS (i.e., pacemaker, cardioverter defibrillator, neuro-stimulation (brain or spinal cord), bone growth stimulations, indwelling blood pressure monitors, epilepsy, pregnancy) patients with confirmed signs of tear dysfunction current participation in another study with an investigational drug or device within one month prior to screening

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Active TENS<br>TENS delivered for 20 minutes to the forehead via the active Cefaly (R) device; at least 3 times per week in-home; for 6 months. | Device: Active Cefaly Dual (R)<br>* Transcutaneous electrical nerve stimulation (TENS) device with electrode placement at the forehead. A biphasic rectangular wave will be delivered for a maximum of 20 minutes at a maximum amplitude of 16mA. Participant may halt amplitude before it reaches maximum amplitude. The device has previously been cleared by the FDA for use in migraine patients.<br>|
| Sham Comparator: Sham TENS<br>Sham TENS delivered for 20 minutes to the forehead via the sham Cefaly (R) device; at least 3 times per week in-home; for 6 months. | Device: Sham Cefaly Dual (R)<br>* Transcutaneous electrical nerve stimulation (TENS) device with electrode placement at the forehead. A 1Hz wave will be delivered for 20 minutes at 1mA.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Side-effect frequency and severity | An open-ended questionnaire of side-effects will be used to assess any bothersome changes in physical or mental health symptoms every 2 weeks during the 6-month at-home course of treatment. Severity, device/treatment-relatedness of symptoms, and desired or actual discontinuation of device use will be recorded. | 1 year | 
| Time to peak change in numerical rating scale (NRS, 0-10) | Calculation of time (weeks) to peak reduction in eye pain will be made based on NRS scores obtained every two weeks after initiation of intervention protocol. | 1 year | 
| Enrollment rate | Percentage of individuals who meet pre-screening requirements, are told about the study, and are consented and enrolled into the study | 1 year | 
| Screen failure rate | The percentage of individuals who meet pre-screening requirements, consent to study procedures, but who do not meet full criteria after screening visit is conducted | 1 year | 
| Treatment compliance rate | Calculation of the percentage of individuals who complete at least 75% of treatment session. | 1 year | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Percentage of individuals who score 100% on checklist for proper use of TENS device | The percentage of individuals who, after instruction, score 100% on checklist items for safe and proper use of the device. | 1 year | 
| Rate of uncertainty in participant treatment allocation guess | Percentage of individuals who rate at least moderate uncertainty in guessing which treatment arm they were allocated to. | 1 year | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Eye pain, Dry Eye, Neuropathic Pain, Transcutaneous Electrical Nerve Stimulation