Recruiting

Light Therapy

Sponsor:

University of North Carolina, Chapel Hill

Code:

NCT05956067

Conditions

Chronic Low-back Pain

Chronic Pain

Fibromyalgia

Eligibility Criteria

Sex: All

Age: 18 - 65

Healthy Volunteers: Not accepted

Interventions

Green Light stimulation

Equal Energy White stimulation

S-cone modulating white light

Study Details

Brief summary:

Participants with chronic pain conditions including chronic low back pain and fibromyalgia may benefit from light stimuli presented to the retina to reduce chronic pain severity and pain sensitivity. Participants will be recruited into this study and will be presented with one of three uniform light stimuli via a wide-field ganzfeld in three conditions to determine the retinal mechanisms that reduce pain. This work will lead to a greater understanding of retinal mechanisms that contribute to pain and will assist the design of future studies to harness the potential of light based pain therapies.

Conditions

Chronic Low-back Pain

Chronic Pain

Fibromyalgia

Study ID

NCT05956067

Start date

Aug 25, 2023

Status verified date

Oct, 2026

Completion date

Oct 9, 2027

Anticipated

Primary completion date

Oct 1, 2027

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18 - 65

Healthy Volunteers: Not accepted

Inclusion Criteria:

  • Adults greater than or equal to 18 and less than or equal to 65.
  • Individuals who have been diagnosed with fibromyalgia or chronic low back pain by their physician.
  • Individuals who experience an average pain severity greater than 4/10 in intensity at baseline.
  • Willingness to wear a battery-operated portable ganzfeld light stimulator device for 2 hours per day at the same time each day (ideally complete the light therapy session between 5 am-10 am each morning) for 5 days.
  • Alert and oriented, and able to provide informed consent
  • Ability to read and speak English to complete validated questionnaires.

Exclusion Criteria:

  • Vision disorders or conditions resulting in severe vision impairment or blindness
  • Individuals with self-report of color blindness
  • Prisoner Status
  • Pregnancy
  • No other history or condition that would, in the investigator's judgment, indicate that the patient would very likely be non-compliant with the study or unsuitable for the study (e.g., might interfere with the study, confound interpretation, or endanger the patient).
  • History of seizure disorder

Study Design

Enrollment

20 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Other

Interventions and Outcome Measures

Arms

experimental: Equal energy white stimulus

Equal energy white light at 500 lux. The International Commission on Illumination (CIE) coordinates of this light are (x=y=0.33), indicating that the stimulus appears uniformly white which means that the activation of each of the three classes of photoreceptors are equivalent, thus silencing any chromatic opponency. The stimulus will be delivered by a portable battery-operated ganzfeld light stimulation device for 2 hours per day for 5 consecutive days.

experimental: Green light stimulus

Green light at 500 lux. Participants will view 545 nm green light delivered via a portable battery-operated ganzfeld light stimulation device for 2 hours per day for 5 consecutive days.

experimental: S-cone modulating white light

The S-cone modulating light stimulus will alternate between two light conditions at 500 lux that will activate the S-cones by about 100x differentially between the two conditions while maintaining the L- an M-cones at constant activation between the two alternating conditions using 427 nm versus 545 nm light. The stimulus will be delivered by a portable battery-operated ganzfeld light stimulation device for 2 hours per day for 5 consecutive days.

Interventions

Green Light stimulation

A portable battery-operated ganzfeld light display will be used to deliver green light for 2 hours per day for 5 consecutive days.

Equal Energy White stimulation

A portable battery-operated ganzfeld light display will be used to deliver white light for 2 hours per day for 5 consecutive days.

S-cone modulating white light

A portable battery-operated ganzfeld light display will be used to deliver S-cone modulating light for 2 hours per day for 5 consecutive days.

Primary outcome measure

  • Feasibility: Percent follow-up [ Time Frame: 1 week ]
  • Feasibility: Percent of flash surveys completed [ Time Frame: 1 week ]
  • Feasibility: Self-reported light stimulation sessions completed [ Time Frame: 1 week ]

Central Contacts and Locations

Central contacts

Matthew C Mauck, MD, PhD

919-966-5136matt_mauck@med.unc.edu

Locations

University Of North Carolina

Recruiting

Chapel Hill, North Carolina, United States, 27517

Contacts

Matthew C Mauck, MD PhD

919-966-5136matt_mauck@med.unc.edu

Principal Investigator:

Matthew C Mauck, MD PhD

More Information

Sponsor

University of North Carolina, Chapel Hill

Last update posted

Nov 2, 2026

Last verified

Oct, 2026

Trial information was received from ClinicalTrials.gov and was last updated on 2026-11-03. This information was provided to ClinicalTrials.gov by University of North Carolina, Chapel Hill on 2026-11-02. Recruitment status is synced daily from ClinicalTrials.gov and may not reflect the sponsor's current status. Confirm during your call.