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NCT Number: NCT05531643

Pilot Study of TENS for Ocular Pain

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.

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Key information

Conditions

Eye Pain Dry Eye Syndromes Eye Diseases Eye Manifestations Lacrimal Apparatus Diseases Nervous System Diseases Neuralgia Neurologic Manifestations Neuromuscular Diseases Pain Pathological Conditions, Signs and Symptoms Peripheral Nervous System Diseases Signs and Symptoms

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Miami VA Healthcare System, Miami, FL

Miami, Florida, 33125, United States

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

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
  • naïve 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

Treatment and study plan

High frequency forehead TENS

Device

Transcutaneous electrical nerve stimulation (TENS) device with electrode placement at the forehead. Biphasic rectangular impulses at 60Hz frequency 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.

Low frequency forehead TENS

Device

Transcutaneous electrical nerve stimulation (TENS) device with electrode placement at the forehead. A 3Hz biphasic square wave will be delivered for 20 minutes up to a maximum amplitude of 16mA.

Primary outcomes

  1. Reported Device-related Side-effects

    Time frame: 6 months

    An open-ended question 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. Presence, description of symptom, severity of symptoms, participant assessment of device/treatment-relatedness of symptoms, and desire or actual discontinuation of device use will be recorded.

  2. Time to Peak Change in Numerical Rating Scale (NRS, 0-10)

    Time frame: 6 months

    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.

  3. Number of Screen Failures

    Time frame: 6 months

    The number of individuals who meet pre-screening requirements, consent to study procedures, but who do not meet full criteria after screening visit is conducted

  4. Treatment Compliance Rate

    Time frame: 6 months

    Count of the number (and calculated percentage) of individuals who reported completing at least 75% of treatment sessions.

Secondary outcomes

  1. Percentage of Individuals Who Score 100% on Checklist for Proper Use of TENS Device

    Time frame: baseline

    The percentage of individuals who, after instruction, score 100% on checklist items for safe and proper use of the device.

  2. Rate of Uncertainty in Participant Treatment Allocation Guess

    Time frame: 6 months

    Percentage of individuals who rate at least moderate uncertainty in guessing which treatment arm they were allocated to.

Other outcomes

  1. Beta Coefficients for Participant Demographics (Sex, Age, Race/Ethnicity) in Regression Model Predicting Adherence to Treatment Protocol

    Time frame: 1 year

    Exploratory regression analysis to identify associations between demographic variables and number of treatment sessions completed

  2. Beta Coefficients for Participant Demographics (Sex, Age, Race/Ethnicity) in Regression Model Predicting Change in Pain (Numerical Rating Scale)

    Time frame: 1 year

    Exploratory regression analysis to identify associations between demographic variables and change in pain ratings (before vs. after 6 month TENS treatment)

Sponsors and collaborators

Lead sponsor

VA Office of Research and Development

Fed

Registry information

Official study title

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

Important dates

Study start
2022
Primary completion
2024
Study completion
2024
First posted
Sep 8, 2022
Registry last updated
Jun 10, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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