Eye Pain
Conditions
Keywords
Eye pain, Dry Eye, Neuropathic Pain, Transcutaneous Electrical Nerve Stimulation
Brief summary
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.
Interventions
DEVICEHigh 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.
DEVICELow frequency forehead TENS
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.
Sponsors
VA Office of Research and Development
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
TRIPLE (Subject, Investigator, Outcomes Assessor)
Masking description
Participants and all study staff involved in participant evaluations will be blinded to treatment allocation. Each device will have the stimulation program pre-set according to the randomization assignment and be numbered. The randomization assignment will be held by the study statistician to match the device number to the intervention assignment. Devices will be distributed in numeric order according to the participant's chronologic order of enrollment.
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Reported Device-related Side-effects | 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) | 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 | 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 | 6 months | Count of the number (and calculated percentage) of individuals who reported completing at least 75% of treatment sessions. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Percentage of Individuals Who Score 100% on Checklist for Proper Use of TENS Device | baseline | The percentage of individuals who, after instruction, score 100% on checklist items for safe and proper use of the device. |
| Rate of Uncertainty in Participant Treatment Allocation Guess | 6 months | Percentage of individuals who rate at least moderate uncertainty in guessing which treatment arm they were allocated to. |
Countries
United States
Contacts
PRINCIPAL_INVESTIGATORElizabeth R Felix, PhD
Miami VA Healthcare System, Miami, FL
Participant flow
Recruitment details
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
Pre-assignment details
Two participants screened out after consent. Thus 37 participants were randomized to treatment. (Some outcome measures (e.g., number of screen failures) are based on the total number of enrolled participants (39); while other outcomes are based on the number of individuals assigned to treatment (37).
Baseline characteristics
| Characteristic | — |
|---|---|
| Age, Continuous | 59 year STANDARD_DEVIATION 9 |
| Ethnicity (NIH/OMB) Hispanic or Latino | 5 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 8 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 0 Participants |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants |
| Race (NIH/OMB) Asian | 1 Participants |
| Race (NIH/OMB) Black or African American | 5 Participants |
| Race (NIH/OMB) More than one race | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants |
| Race (NIH/OMB) White | 8 Participants |
| Sex: Female, Male Female | 12 Participants |
| Sex: Female, Male Male | 18 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 24 | 0 / 13 |
| other Total, other adverse events | 12 / 24 | 10 / 13 |
| serious Total, serious adverse events | 0 / 24 | 0 / 13 |
Outcome results
None listed