Chromatic Retinal Stimulation to Reduce Chronic Pain and Pain Sensitivity

Chronic Pain Clinical Trial

Official title:

Chromatic Retinal Stimulation to Reduce Chronic Pain and Pain Sensitivity

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT05956067
• Other study ID #: 23-1301
• Status: Recruiting
• Phase: N/A
• Start date: August 25, 2023
• Est. completion date: July 29, 2025

Study information

• Verified date: October 2023
• Source: University of North Carolina, Chapel Hill
• Contact: Matthew C Mauck, MD, PhD
• Phone: 919-966-5136
• Email: matt_mauck[@]med.unc.edu
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial 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.

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 60
• Est. completion date: July 29, 2025
• Est. primary completion date: July 17, 2025
• Accepts healthy volunteers: No
• Gender: All
• Age group: 18 Years to 65 Years

Eligibility

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

Related Conditions & MeSH terms

• Chronic Low-back Pain
• Chronic Pain
• Fibromyalgia
• Low Back Pain

Intervention

Device:
• 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.

Locations

Country	Name	City	State
United States	University Of North Carolina	Chapel Hill	North Carolina

Sponsors (1)

Lead Sponsor	Collaborator
University of North Carolina, Chapel Hill

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Feasibility: Percent follow-up	Percent follow-up for 1 week baseline visit. Follow-up greater than 70% will be considered feasible.	1 week
Primary	Feasibility: Percent of flash surveys completed	Percent of flash surveys completed during light stimulation period. 0% is the lowest and 100% is the highest. Higher percentages indicate greater percent of flash surveys completed.	1 week
Primary	Feasibility: Self-reported light stimulation sessions completed	Self-reported light stimulation sessions completed by flash survey administered after each light stimulation session over the 5 day stimulation period. Number of sessions will be reported the minimum is 0 and the maximum is 5.	1 week
Secondary	Change in pain intensity after stimulation	Pain intensity measured by a 0-10 numeric rating scale for overall pain. 0 represents no pain, and 10 represents the worst pain imaginable.	Baseline, 1 week
Secondary	Change in pressure pain threshold	Pressure Pain Threshold is the threshold in which pain is experienced in response to increasing force applied to the trapezius measured by a pressure algometer in kilograms of force per square centimeter (kgf/cm^2). The higher the value, the higher the threshold. The maximum is 10 kgf/cm^2 and minimum is 0.	Baseline, 1 week
Secondary	Change in Conditioned Pain modulation	Conditioned Pain modulation magnitude will be calculated as the difference in mean pressure pain threshold (kgf/cm^2) measured prior to and during the conditioning stimulus (cold water bath), with increases in pressure pain threshold during conditioning interpreted as evidence of efficient endogenous pain inhibition.	Baseline, 1 week
Secondary	Change in Temporal Summation	Temporal Summation. The investigators will evaluate temporal summation using a 40g Neuropen applied to the skin of the volar forearm and lumbar region, following a train of 10 identical stimuli (1 Hz). Participants will report retrospectively, the pain intensity of the 1st and 10th pinprick using a 0-10 numerical rating scale (NRS). 0 is the minimum and 10 is the maximum pain intensity that will be reported.	Baseline, 1 week
Secondary	Change in activity measured with an accelerometer	Activity will be measured by an accelerometer. Average daily step count for the duration of the stimulus. Average non-sedentary time in minutes will able be determined over the stimulation period and compared to the data collected over the 1 week run-in period.	1 week prior to baseline and 1 week during light stimulation