Chromatic Retinal Stimulation to Reduce Chronic Pain and Pain Sensitivity

University of North Carolina (UNC)

Status: Suspended

Conditions: Chronic Low-back Pain; Fibromyalgia; Chronic Pain

Treatments: Device: Equal Energy White stimulation; Device: S-cone modulating white light; Device: Green Light stimulation

Study type: Interventional

Funder types: Other

Identifiers

NCT05956067

23-1301

Details and patient eligibility

About

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.

Enrollment: 60 estimated patients

Sex: All

Ages: 18 to 65 years old

Volunteers: No Healthy Volunteers

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

Trial design

Primary purpose: Other

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

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60 participants in 3 patient groups

Equal energy white stimulus

Experimental group

Description:

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.

Treatment:

Device: Equal Energy White stimulation

Green light stimulus

Experimental group

Description:

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.

Treatment:

Device: Green Light stimulation

S-cone modulating white light

Experimental group

Description:

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.

Treatment:

Device: S-cone modulating white light