An interventional study of High frequency forehead TENS and Low frequency forehead TENS in Eye Pain, sponsored by VA Office of Research and Development. Completed at 1 site in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-06-10.
Sponsored by VA Office of Research and Development · Not applicable, Interventional, and Treatment
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.
23 studies on the registry are indexed under Eye Pain; 7 are open to participants now.
This study's enrollment of 39 is above the median of 35 across 20 interventional studies indexed under Eye Pain.
Browse Eye Pain studies →VA Office of Research and Development is the lead sponsor of 1,733 studies on the registry; 396 are open to participants now.
Of its 206 completed or terminated interventional studies of FDA-regulated products, 180 (87%) have results posted.
Counted across the registry records on this site, refreshed daily.
Exclusion Criteria:
high frequency (60Hz) TENS delivered for 20 minutes to the forehead; at least 3 times per week in-home; for 6 months.
Device: High frequency forehead TENS
low frequency (3Hz) TENS delivered for 20 minutes to the forehead; at least 3 times per week in-home; for 6 months.
Device: Low frequency forehead TENS
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.
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.
Reported Device-related Side-effects
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.
Time frame: 6 months
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.
Time frame: 6 months
Number of Screen Failures
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
Time frame: 6 months
Treatment Compliance Rate
Count of the number (and calculated percentage) of individuals who reported completing at least 75% of treatment sessions.
Time frame: 6 months
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.
Time frame: baseline
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.
Time frame: 6 months
Beta Coefficients for Participant Demographics (Sex, Age, Race/Ethnicity) in Regression Model Predicting Adherence to Treatment Protocol
Exploratory regression analysis to identify associations between demographic variables and number of treatment sessions completed
Time frame: 1 year
Beta Coefficients for Participant Demographics (Sex, Age, Race/Ethnicity) in Regression Model Predicting Change in Pain (Numerical Rating Scale)
Exploratory regression analysis to identify associations between demographic variables and change in pain ratings (before vs. after 6 month TENS treatment)
Time frame: 1 year
enrollment includes all individuals who signed the informed consent form with intent to complete the study and who attended the initiating/baseline visit of the study
| Milestone | High Frequency TENS | Low Frequency TENS |
|---|---|---|
| Started | 24 | 13 |
| Completed | 17 | 10 |
| Not completed | 7 | 3 |
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.
| partcipants | High Frequency TENS | Low Frequency TENS |
|---|---|---|
| # of people reporting | 12 | 10 |
| # of people temporary discontinue device use | 4 | 2 |
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.
| weeks after start of treatment | High Frequency TENS | Low Frequency TENS |
|---|---|---|
| Time to Peak Change in Numerical Rating Scale (NRS, 0-10) | 13 (6 to 17.5) | 10 (2 to 17) |
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
| Participants | Across Study |
|---|---|
| Number of Screen Failures | 2 |
Count of the number (and calculated percentage) of individuals who reported completing at least 75% of treatment sessions.
| Participants | High Frequency TENS | Low Frequency TENS |
|---|---|---|
| Treatment Compliance Rate | 6 | 5 |
The percentage of individuals who, after instruction, score 100% on checklist items for safe and proper use of the device.
| Participants | High Frequency TENS | Low Frequency TENS |
|---|---|---|
| Percentage of Individuals Who Score 100% on Checklist for Proper Use of TENS Device | 24 | 13 |
Percentage of individuals who rate at least moderate uncertainty in guessing which treatment arm they were allocated to.
| Participants | High Frequency TENS | Low Frequency TENS |
|---|---|---|
| Rate of Uncertainty in Participant Treatment Allocation Guess | 10 | 7 |
Exploratory regression analysis to identify associations between demographic variables and number of treatment sessions completed
Results for this outcome have not been posted.
Exploratory regression analysis to identify associations between demographic variables and change in pain ratings (before vs. after 6 month TENS treatment)
Results for this outcome have not been posted.
Collected over from initiation of first treatment session until the end of the six month intervention period. Non-serious events are listed at a 0% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| High Frequency TENS | 0/24 (0%) | 0/24 (0%) | 12/24 (50%) |
| Low Frequency TENS | 0/13 (0%) | 0/13 (0%) | 10/13 (76.9%) |
| Event | High Frequency TENS | Low Frequency TENS |
|---|---|---|
| headacheNervous system disorders | 5/24 | 7/13 |
| forehead dysesthetic sensationNervous system disorders | 4/24 | 2/13 |
| ear dysesthetic sensationsNervous system disorders | 2/24 | 0/13 |
| skin rashSkin and subcutaneous tissue disorders | 1/24 | 1/13 |
| Age, Continuous(year) | High Frequency TENS | Low Frequency TENS | Total |
|---|---|---|---|
| Mean | 59 ± 9 | 56 ± 16 | 58 ± 12 |
| Sex: Female, Male(Participants) | High Frequency TENS | Low Frequency TENS | Total |
|---|---|---|---|
| Female | 12 | 7 | 19 |
| Male | 12 | 6 | 18 |
| Race (NIH/OMB)(Participants) | High Frequency TENS | Low Frequency TENS | Total |
|---|---|---|---|
| American Indian or Alaska Native | 0 | 0 | 0 |
| Asian | 1 | 0 | 1 |
| Native Hawaiian or Other Pacific Islander | 0 | 0 | 0 |
| Black or African American | 5 | 5 | 10 |
| White | 18 | 8 | 26 |
| More than one race | 0 | 0 | 0 |
| Unknown or Not Reported | 0 | 0 | 0 |
| Ethnicity (NIH/OMB)(Participants) | High Frequency TENS | Low Frequency TENS | Total |
|---|---|---|---|
| Hispanic or Latino | 12 | 5 | 17 |
| Not Hispanic or Latino | 12 | 8 | 20 |
| Unknown or Not Reported | 0 | 0 | 0 |
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