Colored-light pain relief and brain mapping in chronic musculoskeletal pain

Neural Mechanisms of Light Driven Analgesia

NA · University of North Carolina, Chapel Hill · NCT07245303

This trial will test whether showing different colored lights to the eyes can reduce pain and change brain activity in adults with chronic musculoskeletal pain compared with healthy, age- and sex-matched controls.

Quick facts

PhaseNA
Study typeInterventional
Enrollment60 (estimated)
Ages18 Years and up
SexAll
SponsorUniversity of North Carolina, Chapel Hill (other)
Locations1 site (Chapel Hill, North Carolina)
Trial IDNCT07245303 on ClinicalTrials.gov

What this trial studies

Researchers will enroll 30 adults with chronic musculoskeletal pain and 30 age- and sex-matched healthy controls who will undergo quantitative sensory testing and fMRI. Participants will receive three different colored retinal light stimuli and an evoked pressure pain stimulus while whole-brain activity and functional connectivity are recorded. Pain sensitivity, conditioned pain modulation, and brief pain ratings during scanning will be collected to correlate with BOLD signal changes. Imaging data will be preprocessed for quality control and analyzed to identify neural circuits linking visual input to pain modulation.

Who should consider this trial

Good fit: Ideal participants are adults (≥18) with chronic musculoskeletal pain meeting the 2016 fibromyalgia-related WPI/SSS criteria, with pain for ≥3 months in at least 4 of 5 body regions, average monthly pain ≥4/10, willing and able to undergo MRI, not planning treatment or medication changes, and able to read and speak English.

Not a fit: Patients who cannot undergo MRI (for example due to claustrophobia or incompatible implants), who have planned treatment changes, who do not meet the fibromyalgia/musculoskeletal inclusion criteria, or whose pain is from other unrepresented causes may not receive benefit from this protocol.

Why it matters

Potential benefit: If successful, the findings could point to a non-drug way to reduce pain using specific light exposures and identify brain circuits for future targeted therapies.

How similar studies have performed: Preclinical studies and some small clinical reports have shown retinal light can relieve pain, but using fMRI to map the detailed neural mechanisms in chronic musculoskeletal pain is relatively novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria for participants with cMSP and healthy controls (n=30)

* Adults ≥18 years of age.
* Individuals who do not have any plans for medication or treatment changes for the next 3 months.
* Participants must be willing and able to undergo an MRI.
* Participants must not be claustrophobic
* Participants must be alert and oriented and able to provide informed consent.
* Individuals must be able to speak and read English.

Inclusion Criteria for participants with cMSP only (n=30)

* To be eligible, participants must have a score of ≥7 on the Widespread pain index (WPI) and ≥5 on the symptom severity scale (SSS), or 4-6 on the WPI and ≥9 on the SSS in the 2016 Fibromyalgia Questionnaire.
* Pain symptoms must have been present for 3 months or longer.
* Pain must be present in 4 out of 5 body regions.
* Individuals enrolled will have an average pain severity ≥4 on the 0-10 NRS over the month prior to enrollment to recruit individuals with moderate to severe chronic MSP.

Inclusion Criteria for Participants with Congenital Stationary Night Blindness (n=2)

-2 additional participants without chronic MSP will be recruited with diagnosed congenital stationary night blindness

Exclusion Criteria:

* Presence of retinal vision disorders or conditions resulting in vision impairment.
* Patient-reported photosensitivity, photophobia, or aversion (as may occur in autoimmune diseases such as systematic lupus erythematosus).
* Disorders including uveitis, cataracts, color-blindness, history of seizure disorder.
* Plans for analgesic treatment plan changes in next 3 months (surgery, analgesic medication changes, injections, pain procedures, etc).
* Prisoner Status.
* Pregnancy.
* Contraindications to MRI imaging. These include the presence of implanted/embedded ferromagnetic materials, implanted medical devices that are not MRI compatible, and claustrophobia.

Where this trial is running

Chapel Hill, North Carolina

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.

View on ClinicalTrials.gov →

Conditions: Musculoskeletal Pain, Fibromyalgia, Healthy Controls Group - Age and Sex-matched, functional connectivity, colored light analgesia, functional magnetic resonance imaging, quantitative sensory testing

Last reviewed 2026-05-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.