Eye PainNCT05531643

Pilot Study of TENS for Ocular Pain

A study testing High frequency forehead TENS and Low frequency forehead TENS in people with Eye Pain, run by VA Office of Research and Development at 1 site in United States.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record

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Trial summary

Who is it for?: Ages 18 years and older
Conditions the study is for: Eye Pain
What is being tested?: High frequency forehead TENS and Low frequency forehead TENS
Type of treatment: Medical device
Could I receive a placebo?: No, everyone receives an active treatment
How many people: 39 participants
Where: 1 siteUnited States
Study dates: 3 Oct 2022to 30 Nov 2024
Phase: Interventional
Are there results?: Yes, posted in the registrySummary in the doctors' view

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

Ages 18 years and older
All sexes
No healthy volunteers
Adult, Older adult

Who may be able to join

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

Who cannot join

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

Trial locations and contacts

1 site in 1 country.

United States1 site

Miami VA Healthcare System, Miami, FL
Miami, Florida, 33125

Other trials in United States

About this study

Official title: A Pilot Study of the Safety and Feasibility of Transcutaneous Electrical Nerve Stimulation (TENS) for Chronic 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.

Conditions: Eye Pain
Being tested: High frequency forehead TENS, Low frequency forehead TENS
Keywords: Eye pain, Dry Eye, Neuropathic Pain, Transcutaneous Electrical Nerve Stimulation
Medical subject headings: Eye Pain, Dry Eye Syndromes, Neuralgia

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

High frequency forehead TENSDevice
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 TENSDevice
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.

Study groups in NCT05531643
Study group	Role	What they receive
high frequency TENS	Experimental	high frequency (60Hz) TENS delivered for 20 minutes to the forehead; at least 3 times per week in-home; for 6 months. Receives: Device: High frequency forehead TENS
low frequency TENS	Active comparator	low frequency (3Hz) TENS delivered for 20 minutes to the forehead; at least 3 times per week in-home; for 6 months. Receives: Device: Low frequency forehead TENS

What is being measured

The primary outcome is the main question the study is designed to answer.

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.
Measured: 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.
Measured: 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
Measured: 6 months
Treatment Compliance Rate
Count of the number (and calculated percentage) of individuals who reported completing at least 75% of treatment sessions.
Measured: 6 months

Secondary outcomes (2)

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.
Measured: 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.
Measured: 6 months

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

3 Oct 202230 Nov 2024

First posted8 Sep 2022
Study start3 Oct 2022
Primary completion30 Nov 2024
Study completion30 Nov 2024

Resources

Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
Publications (1)Papers the sponsor has linked to this study.
Other trials for Eye PainStudies of the same condition, open and under way.
More trials run by VA Office of Research and DevelopmentThe sponsor's other registered studies.
What the trial phases meanHow a treatment moves from first tests in people to approval.

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design

Study type: Interventional
Phase: Phase N/A
Primary purpose: Treatment
Allocation: Randomised
Intervention model: Parallel groups
Masking: Triple blind
Who is masked: Participant, Investigator, Outcomes assessor
Enrolment: 39 participants (actual)

IDs, dates and publications

ClinicalTrials.gov ID: NCT05531643
Sponsor's protocol ID: F3883-P
Status last verified: May 2026
First submitted: 30 Aug 2022
Last updated: 10 Jun 2026
Results posted: Yes, on ClinicalTrials.gov
Data monitoring committee: No
FDA-regulated drug: No
FDA-regulated device: Yes
Individual data sharing: No

Publications

Shields C, Qazi S, Zaldivar A, Cabrera K, Mangwani-Mordani S, Peterson H, Bhatt S, Tang F, Galor A, Felix ER. Randomized Pilot Study of Transcutaneous Electrical Nerve Stimulation for Neuropathic/Nociplastic Ocular Pain. Am J Ophthalmol. 2026 Jun;286:318-331. doi: 10.1016/j.ajo.2026.03.008. Epub 2026 Mar 10.
PubMed 41812852

Want to know more?

The sponsor has not listed a contact. The official record may have more details.

Talk to your doctor first and take this page with you. Only the study team can confirm whether you can join.

Questions to ask the study team

What is the study trying to find out?
What would I need to do, and how often would I visit?
Could I receive a placebo instead of the treatment?
What are the possible risks and benefits for me?
Will it cost me anything? Are travel or time paid for?
Can I keep seeing my own doctor during the study?
What happens when the study ends?

See locations

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All Eye Pain trials

Study at a glance

From the registry record, last updated by the sponsor on 10 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title: A Pilot Study of the Safety and Feasibility of Transcutaneous Electrical Nerve Stimulation (TENS) for Chronic Ocular Pain
ClinicalTrials.gov ID: NCT05531643
Acronym / sponsor ID: F3883-P
Conditions: Eye Pain
Keywords: Eye pain, Dry Eye, Neuropathic Pain, Transcutaneous Electrical Nerve Stimulation
Study type: Interventional
Recruitment status: Completed
Enrolment: 39 participants (actual)
Lead sponsor: VA Office of Research and DevelopmentUS federal agency
Study start: 3 Oct 2022 (actual)
Primary completion: 30 Nov 2024 (actual)
Study completion: 30 Nov 2024 (actual)
First posted: 8 Sep 2022 (actual)
Results: Posted 10 Jun 2026

Clinical summary

The research question as the sponsor registered it. This describes what the study plans to test, not what it found.

Study design

Primary purpose: Treatment
Allocation: Randomised
Intervention model: Parallel groups
Masking: Triple blind (participant, investigator, outcomes assessor)
Number of arms: 2

Arm	Type	Receives
high frequency TENS	Experimental	Device: High frequency forehead TENShigh frequency (60Hz) TENS delivered for 20 minutes to the forehead; at least 3 times per week in-home; for 6 months.
low frequency TENS	Active comparator	Device: Low frequency forehead TENSlow frequency (3Hz) TENS delivered for 20 minutes to the forehead; at least 3 times per week in-home; for 6 months.

Who may qualify

Ages: 18 years and older
Sex: All
Healthy volunteers: Not accepted
Age groups: Adult, Older adult

Key inclusion criteria (8 listed)

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

Key exclusion criteria (4 listed)

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

Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.

Interventions

Intervention	Type	Arms
High frequency forehead TENSTranscutaneous 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.	Device	high frequency TENS
Low frequency forehead TENSTranscutaneous 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.	Device	low frequency TENS

Primary outcome

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.
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.
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
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.

2 secondary outcomes

Percentage of Individuals Who Score 100% on Checklist for Proper Use of TENS Device
Time frame: baseline
Rate of Uncertainty in Participant Treatment Allocation Guess
Time frame: 6 months

Results and safety

Results posted to the registry on 10 Jun 2026, as reported by the sponsor. Figures are copied from the record, not re-analysed. Full results on ClinicalTrials.gov.

Participant flow

Group	Started	Completed
High Frequency TENS	24	17
Low Frequency TENS	13	10

Primary outcome: Reported Device-related Side-effects

Time frame: 6 months. Number. Unit: partcipants

Measure	High Frequency TENS n = 24	Low Frequency TENS n = 13
# of people reporting	12	10
# of people temporary discontinue device use	4	2

Primary outcome: Time to Peak Change in Numerical Rating Scale (NRS, 0-10)

Time frame: 6 months. Median (Inter-Quartile Range). Unit: weeks after start of treatment

Measure	High Frequency TENS n = 14	Low Frequency TENS n = 12
Value	13 (6 to 17.5)	10 (2 to 17)

Population analysed: Calculation to peak reduction was only made for those who had at least a 1pt reduction in pain on the 0-10 NRS from baseline at at least one time point after baseline

Primary outcome: Number of Screen Failures

Time frame: 6 months. Count of participants. Unit: Participants

Measure	Across Study n = 39
Value	2

Primary outcome: Treatment Compliance Rate

Time frame: 6 months. Count of participants. Unit: Participants

Measure	High Frequency TENS n = 24	Low Frequency TENS n = 13
Value	6	5

Population analysed: Calculated based on all participants who were assigned to a treatment group - how many completed at least 75% of sessions based on self-report across the 6 month intervention period

2 secondary outcomes are reported in the full results.

Adverse events

Time frame: from initiation of first treatment session until the end of the six month intervention period. Other adverse events reported at 0% frequency or more

Group	Serious adverse events	Other adverse events	Deaths
High Frequency TENS	0 of 24 (0%)	12 of 24 (50%)	0 of 24
Low Frequency TENS	0 of 13 (0%)	10 of 13 (76.9%)	0 of 13

Limitations and caveats (from the sponsor): This was a pilot investigation, primarily targeted to determine what methodology changes might be needed to ensure feasibility for a fully-powered clinical trial of TENS for chronic ocular pain. As such, many limitations are present within the results, and all reported information should be interpreted with caution.

Loading the posted results from ClinicalTrials.gov…

Research links

Official record on ClinicalTrials.govLast updated by the sponsor 10 Jun 2026.
Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
Derived from this study: PubMed 41812852Shields C, Qazi S, Zaldivar A, Cabrera K, Mangwani-Mordani S, Peterson H, Bhatt S, Tang F, Galor A, Felix ER. Randomized Pilot Study of Transcutaneous Electrical Nerve Stimulation for Neuropathic/Nociplastic Ocular Pain. Am J Ophthalmol. 2026 Jun;286:318-331. doi: 10.1016/j.ajo.2026.03.008. Epub 2026 Mar 10.
Individual participant dataSharing planned: No

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Referral and contact

AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.

Elizabeth R Felix, PhD principal investigator

Miami VA Healthcare System, Miami, FL

1 site in 1 country: see every site and its status.

Questions about this trial

What is this clinical trial studying?

A study testing High frequency forehead TENS and Low frequency forehead TENS in people with Eye Pain, run by VA Office of Research and Development at 1 site in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 8 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 10 Jun 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

Yes. Results are posted in the registry (first posted 10 Jun 2026). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Reported Device-related Side-effects (time frame: 6 months). The study lists 4 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT05531643, which also lists 1 linked publication.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 10 Jun 2026.