Effect of Green Light Exposure at Different Times on the Pain of Subjects

NCT07033949 | Completed

• 1 other identifier: GLE
• Study Type: interventional
• Target: 140
• Locations: 1 country
• Sites: 1

Brief Summary

This study investigated the effects of green-light exposure on pain sensitivity in healthy volunteers and on perioperative pain in surgical patients. Healthy volunteers underwent 30-min green-light exposure at three different times of day (08:00-09:00, 12:00-13:00, and 16:00-17:00) on separate days using a within-subject design, with a washout period of at least 2 days between sessions. Surgical patients undergoing elective surgery under general anesthesia with preoperative arterial puncture were randomly assigned in a 1:1 ratio to either a green-light intervention group or a sham-device control group. The assigned intervention was initiated before arterial puncture and continued throughout surgery. The effects of green-light exposure on pain sensitivity, procedural pain, and perioperative pain were evaluated.

Conditions

Pain

Keywords

Acute Pain; Green light

Outcome Measures

Primary Outcomes (1)

• Pain intensity during arterial puncture

  Numeric Rating Scale (NRS), ranging from 0 to 10, with higher scores indicating greater pain intensity.

  The pain score during arterial puncture

Secondary Outcomes (4)

• Pain sensitivity

  Immediately before and 30 minutes after light exposure

• Analgesic consumption during surgery

  From surgery beginning to the ending of the surgery

• Pain intensity after surgery

  From ending of the surgery to 24 hours after surgery

• Analgesic consumption after surgery

  From ending of the surgery to 24 hours after surgery

Other Outcomes (1)

• Heart rate

  from before arterial puncture to 5 minutes after the arterial puncture

Study Arms (2)

Green light exposure group

EXPERIMENTAL

Participants wore GLED light-therapy glasses delivering 511-515 nm green light at 100 lux for 30 min before arterial puncture and throughout surgery.

Device: Green light glasses

Sham-device control group

SHAM COMPARATOR

Participants wore identical GLED light-therapy glasses for 30 min before arterial puncture and throughout surgery. The device remained powered off, and participants were exposed only to ambient room light.

Device: Sham GLED glasses

Interventions

Green light glasses DEVICE

Exposure to green light for 30 minutes and during the surgery.

Green light exposure group

Sham GLED glasses DEVICE

Identical GLED glasses remained powered off for 30 min before arterial puncture and throughout surgery.

Sham-device control group

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Healthy volunteers:
• Age 18-65 years.
• ASA physical status I.
• \. Age 18-65 years. 2. ASA physical status I-III. 3. Scheduled for elective abdominal surgery under general anesthesia requiring arterial puncture.

You may not qualify if:

• Skin ulceration, dermatitis, or allergic reactions at the study site.
• Chronic use of analgesics or psychiatric medications.
• Color blindness or uncorrected cataracts.
• Severe cardiovascular, respiratory, or inflammatory diseases.
• Failure of the initial arterial puncture attempt (surgical cohort only).
• Inability to communicate or provide informed consent.

Sponsors & Collaborators

• The Second Affiliated Hospital of Chongqing Medical University: lead

Study Sites (1)

The Second Affiliated Hospital of Chongqing Medical University

Chongqing, Chongqing Municipality, 4000000, China

Location

MeSH Terms

Conditions

Pain; Acute Pain

Condition Hierarchy (Ancestors)

Neurologic Manifestations; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Study Officials

• Guangyou Duan

  The Second Affiliated Hospital, Chongqing Medical University

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: June 15, 2025
• First Posted: June 24, 2025
• Study Start: July 1, 2025
• Primary Completion: April 4, 2026
• Study Completion: April 6, 2026
• Last Updated: September 17, 2026

Record last verified: 2026-09

Locations

CN (1)