NCT05295225

Brief Summary

This research project is intended to understand the mechanisms of action for the pain-relieving properties of visual green light exposure. The investigators have shown previously that greenlight exposure decreased acute and chronic pain in both animals and humans. However, the investigators do not yet understand how green light exposure is capable of such function.

Trial Health

75
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
30

participants targeted

Target at below P25 for not_applicable chronic-pain

Timeline
7mo left

Started Jun 2022

Longer than P75 for not_applicable chronic-pain

Geographic Reach
1 country

1 active site

Status
active not recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

Study Progress87%
Jun 2022Dec 2026

First Submitted

Initial submission to the registry

February 22, 2022

Completed
1 month until next milestone

First Posted

Study publicly available on registry

March 25, 2022

Completed
3 months until next milestone

Study Start

First participant enrolled

June 14, 2022

Completed
4.6 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

December 31, 2026

Expected
Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

December 31, 2026

Last Updated

January 5, 2026

Status Verified

December 1, 2025

Enrollment Period

4.6 years

First QC Date

February 22, 2022

Last Update Submit

December 29, 2025

Conditions

Outcome Measures

Primary Outcomes (2)

  • Ascending Pain Pathway

    Changes in activity of the ascending pain pathway

    Two hours

  • Descending Pain Pathway

    Changes in activity of the descending pain pathway

    Two hours

Secondary Outcomes (5)

  • Delta Brain Activities

    Two hours

  • Theta Brain Activities

    Two hours

  • Alpha Brain Activities

    Two hours

  • Sigma Brain Activities

    Two hours

  • Beta Brain Activities

    Two hours

Study Arms (2)

Green Light Exposure

ACTIVE COMPARATOR

Subjects will complete thermal and mechanical pain threshold detection tests and Electroencephalography (EEG). After completion, subjects will be exposed to a green light-emitting diode for two hours. After exposure, thermal and mechanical pain threshold assessments and Electroencephalography (EEG) will be conducted.

Device: Green Light Emitting Diode

White Light Exposure

PLACEBO COMPARATOR

Subjects will complete thermal and mechanical pain threshold detection tests and Electroencephalography (EEG). After completion, subjects will be exposed to a white light-emitting diode for two hours. After exposure, thermal and mechanical pain threshold assessments and Electroencephalography (EEG) will be conducted.

Device: White Light Emitting Diode

Interventions

GLED exposure for two hours

Also known as: GLED
Green Light Exposure

WLED exposure for two hours

Also known as: WLED
White Light Exposure

Eligibility Criteria

Age18 Years - 50 Years
Sexall
Healthy VolunteersYes
Age GroupsAdult (18-64)

You may qualify if:

  • years healthy men or women
  • Able to speak and understand English
  • No history of Chronic pain
  • No known neuropathies in areas that testing will take place, (forearms, muscle at the base of thumb on the palm of the hand and upper back/shoulder area.

You may not qualify if:

  • Serious mental illness defined as distortions of perception, delusions, hallucinations, and unusual behaviors resulting in loss of contact with reality. This will be assessed during the screening interview.
  • Colorblindness or uncorrected cataracts.
  • Tissue damage in areas that testing will take place, (forearms, muscle at the base of the thumb on the palm of the hand, and upper back/should area.

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

Banner University Medical Center Tucson

Tucson, Arizona, 85724, United States

Location

Related Publications (1)

  • Ibrahim MM, Patwardhan A, Gilbraith KB, Moutal A, Yang X, Chew LA, Largent-Milnes T, Malan TP, Vanderah TW, Porreca F, Khanna R. Long-lasting antinociceptive effects of green light in acute and chronic pain in rats. Pain. 2017 Feb;158(2):347-360. doi: 10.1097/j.pain.0000000000000767.

MeSH Terms

Conditions

Chronic Pain

Condition Hierarchy (Ancestors)

PainNeurologic ManifestationsSigns and SymptomsPathological Conditions, Signs and Symptoms

Study Officials

  • Mohab Ibrahim, PhD, MD.

    University of Arizona

    PRINCIPAL INVESTIGATOR

Study Design

Study Type
interventional
Phase
not applicable
Allocation
RANDOMIZED
Masking
NONE
Purpose
BASIC SCIENCE
Intervention Model
PARALLEL
Sponsor Type
OTHER
Responsible Party
PRINCIPAL INVESTIGATOR
PI Title
Associate Professor, Anesthesiology

Study Record Dates

First Submitted

February 22, 2022

First Posted

March 25, 2022

Study Start

June 14, 2022

Primary Completion (Estimated)

December 31, 2026

Study Completion (Estimated)

December 31, 2026

Last Updated

January 5, 2026

Record last verified: 2025-12

Data Sharing

IPD Sharing
Will not share

Locations