Skip to main content
OpenTrials
Recruiting

NCT Number: NCT06371300

Photobiomodulation With REd vs BluE Light (REBEL)

The use of photobiomodulation or low-level light therapy (LLLT) in the ophthalmic field stemmed from dermatology which has shown impact on skin blood flow and regeneration. There has been a rise in clinical interest with emerging evidence in the benefits of photobiomodulation in managing chronic inflammatory conditions such as dry eye disease including improvements in ocular discomfort symptoms, tear film stability and tear volume. Despite the observed clinical benefits, limited research has been done to compare photobiomodulation utilising different wavelengths, as most research on dry eye disease has focused on red wavelengths. It has been purported that blue wavelengths may disrupt microbial growth while red wavelengths stimulate energy production and hence increase heat in the affected tissues, although research into these differential impacts at the ocular surface and external eye has been limited. Hence, the aim of this exploratory clinical trial is to compare the impact of using LLLT incorporating red versus blue wavelengths on eyelid haemodynamics and microbiome, as well as conventional ocular surface measures of patients with dry eye disease and blepharitis (inflammation of the eyelids).

Participants with dry eye disease, oil gland disruption and blepharitis will receive 3 treatments with these LLLT, each separted by 1 week apart, and followed up to 1 month after the final treatment session. Participants will be randomised to either of 3 groups: Red light only group, Red + Blue light group, or a sham treatment group.

Recruiting

Interested in participating?

Request Info

Key information

Conditions

Dry Eye Syndromes Blepharitis Eye Diseases Eyelid Diseases Lacrimal Apparatus Diseases Meibomian Gland Dysfunction

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

University of Auckland, Auckland, New Zealand

Loading trial locations.

About this study

This study will be a randomized, double-masked, exploratory clinical study to assess the potential difference in impact between the two wavelengths used for LLLT. The whole study involves a total of 4 visits (consisting of 3 treatment visits, and 1 follow-up visit). All visits will be conducted at the Aston Dry Eye Clinic in Aston University, Birmingham, United Kingdom.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Individuals with dry eye disease symptoms (Ocular Surface Disease Index questionnaire (OSDI) score ≥ 13 or Dry Eye Questionnaire (DEQ5) score > 6) and signs (tear film instability measured with non-invasive tear break-up time < 10 s or ocular surface damage measured using special dyes placed on the front surface of the eyes that temporarily stains any aggravated or damaged cells: > 5 corneal spots, > 9 conjunctival spots or lid margin staining ≥ 2mm in length and ≥ 25% in width)
  • Individuals need to also have Meibomian gland dysfunction. The diagnosis of Meibomian gland dysfunction depends on how many of 5 glands in the central lower eyelid can express oil, and the quality of the oil. A diagnosis is made if there is decreased expressibility (grade 1-3 on the Pflugfelder scale) and reduced quality of oil (grade 1-3 on Bron scale). Any presence of gland blockage and/or loss of oil glands grade 1 to grade 4 of either eyelid [Pult and Reide-Pult, 2013]) will also justify a diagnosis of Meibomian gland dysfunction.
  • Individuals will also need to have ocular demodicosis, diagnosed by clinical observation on slit lamp biomicroscope based on signs including collarettes around the base of lashes, visible Demodex tails, or excessive pouting of lash follicles in those with good lid hygiene where Demodex was confirmed by secondary means such as visible Demodex tails.
  • Age ≥ 18 years, male or female
  • Able to provide written consent in English
  • Able to attend a total of 4 visits: 3 treatment visits and followed up for 1 month after final treatment

Exclusion criteria

  • Pregnancy
  • Ocular light-based therapies including intense pulsed light (IPL) or LLLT treatment within the past 1 month or during study period in addition to those provided in the study
  • Contact lens wear in the past 2 weeks or during study period
  • Other active ocular surface diseases or history of ocular surgery or corneal infections the past 6 months

Treatment and study plan

Red LLLT

Device

Mask with LEDs emitting at wavelengths of 633nm to facial and eyelids region with their eyes closed

Blue LLLT

Device

Mask with LEDs emitting at wavelengths of 428nm to facial and eyelid regions with their eyes closed

Sham Red LLLT

Device

Mask with LEDs emitting at wavelengths of 633nm, but with <10% fluence power output, to facial and eyelids region with their eyes closed

Sham Blue LLLT

Device

Mask with LEDs emitting at wavelengths of 428nm, but with <10% fluence power output, to facial and eyelids region with their eyes closed

Primary outcomes

  1. Change from Baseline in Bacterial Colony to the Final Follow-up 1 Month After Final Treatment Session

    Time frame: Baseline up to 1 month after final treatment session

    Measure of number of bacterial colonisation obtained from eyelid swabs

Secondary outcomes

  1. Change from Baseline in Visual Acuity to the Final Follow-up 1 Month After Final Treatment Session

    Time frame: Baseline up to 1 month after final treatment session

    Subjective measure of visual acuity using Logarithm of the Minimum Angle Resolution (logMAR) scoring, ranging from -0.30 which signify the ability to be able to resolve the smallest letters, to 1.00 which signify the ability to resolve only the largest letters

  2. Change from Baseline in Non-invasive Tear Break Up Time to the Final Follow-up 1 Month After Final Treatment Session

    Time frame: Baseline and 1 month after final treatment session

    Measure of the stability of tears and how fast the tears evaporate in seconds using the Oculus Keratograph 5M instrument. An average of 3 measurements is obtained.

  3. Change from Baseline in Blink Rate to the Final Follow-up 1 Month After Final Treatment Session

    Time frame: Baseline up to 1 month after final treatment session

    Manual subjective count of the number of blinks using the Oculus Keratograph 5M instrument.

  4. Change from Baseline in Tear Meniscus Height to the Final Follow-up 1 Month After Final Treatment Session

    Time frame: Baseline up to 1 month after final treatment session

    Measure of the volume of tears in mm using the Oculus Keratograph 5M instrument. An average of 3 measurements is obtained.

  5. Change from Baseline in Lipid Layer Pattern Grading to the Final Follow-up 1 Month After Final Treatment Session

    Time frame: Baseline up to 1 month after final treatment session

    Subjective grading of the appearance of the lipid layer pattern as a surrogate measure of its thickness using the Oculus Keratograph 5M instrument. This ranges from Grade 1 indicating very thin lipid layer to Grade 6 indicating very thick lipid layer.

  6. Change from Baseline in Bulbar Conjunctival Hyperaemia to the Final Follow-up 1 Month After Final Treatment Session

    Time frame: Baseline up to 1 month after final treatment session

    Automated objective grading of the bulbar conjunctival redness using the Oculus Keratograph 5M instrument. This ranges from Grade 0 indicating no redness to Grade 4 indicating substantial redness.

  7. Change from Baseline in Limbal Conjunctival Hyperaemia to the Final Follow-up 1 Month After Final Treatment Session

    Time frame: Baseline up to 1 month after final treatment session

    Automated objective grading of the limbal conjunctival redness using the Oculus Keratograph 5M instrument. This ranges from Grade 0 indicating no redness to Grade 4 indicating substantial redness.

  8. Change from Baseline in Blood Flow to the Final Follow-up 1 Month After Final Treatment Session

    Time frame: Baseline up to 1 month after final treatment session

    Measure of blood flow using laser doppler flowmetry instrument.

  9. Change from Baseline in Saponification Grading to the Final Follow-up 1 Month After Final Treatment Session

    Time frame: Baseline up to 1 month after final treatment session

    Measure of saponification on a scale of 0 (no saponification) to 3 (severe saponification)

  10. Change from Baseline in Demodex Presence to the Final Follow-up 1 Month After Final Treatment Session

    Time frame: Baseline up to 1 month after final treatment session

    Subjective assessment of the amount of Demodex present at the base of the lashes using slit lamp biomicroscopy and white light illumination.

  11. Change from Baseline in Number of Blocked or Capped Meibomian Glands to the Final Follow-up 1 Month After Final Treatment Session

    Time frame: Baseline up to 1 month after final treatment session

    Subjective assessment of the number of blocked or capped Meibomian Glands using slit lamp biomicroscopy and white light illumination.

  12. Change from Baseline in Lid Margin Telangiectasia Grading to the Final Follow-up 1 Month After Final Treatment Session

    Time frame: Baseline up to 1 month after final treatment session

    Subjective grading of the amount of telangiectasia at the lid margins using slit lamp biomicroscopy and white light illumination. This grading ranges from 0 with no telangiectasia to 3 with severe telangiectasia.

  13. Change from Baseline in Meibum Expressibility to the Final Follow-up 1 Month After Final Treatment Session

    Time frame: Baseline up to 1 month after final treatment session

    Subjective grading of meibum expressibility of lower eyelids using slit lamp biomicroscopy and white light illumination. This grading ranges from 0 with all glands being expressible to 3 with no glands being expressible.

  14. Change from Baseline in Meibum Quality to the Final Follow-up 1 Month After Final Treatment Session

    Time frame: Baseline up to 1 month after final treatment session

    Subjective grading of meibum quality of lower eyelids using slit lamp biomicroscopy and white light illumination. This grading ranges from 0 with clear fluid being expressed to 3 with inspissated toothpaste-like expression.

  15. Change from Baseline in Fluorescein Corneal Staining to the Final Follow-up 1 Month After Final Treatment Session

    Time frame: Baseline up to 1 month after final treatment session

    Subjective grading of the amount of corneal staining using fluorescein instillation, cobalt blue light illumination and the Oxford grading scale. This ranges from 0 with no staining to 5 with intense staining.

  16. Change from Baseline in Bulbar Conjunctival Staining to the Final Follow-up 1 Month After Final Treatment Session

    Time frame: Baseline up to 1 month after final treatment session

    Subjective grading of the amount of bulbar conjunctival staining using fluorescein and lissamine green instillation, white light illumination and the Oxford grading scale. This ranges from 0 with no staining to 5 with intense staining.

  17. Change from Baseline in Lissamine Green Lid Wiper Epitheliopathy to the Final Follow-up 1 Month After Final Treatment Session

    Time frame: Baseline up to 1 month after final treatment session

    Subjective grading of the amount of lid wiper epitheliopathy using lissamine green instillation and white light illumination. This grading ranges from 0 with no lid wiper epitheliopathy to 4 with severe lid wiper epitheliopathy.

  18. Change from Baseline in Meibography Meiboscore to the Final Follow-up 1 Month After Final Treatment Session

    Time frame: Baseline up to 1 month after final treatment session

    Subjective grading of the amount of Meibomian gland loss using infrared imaging and the Pult meiboscore. This grading ranges from 0 with no gland loss to 4 with severe gland loss (Pult and Reide-Pult, 2013).

  19. Change from Baseline in MMP-9 Tear Concentration to the Final Follow-up 1 Month After Final Treatment Session

    Time frame: Baseline up to 1 month after final treatment session

    Measure of matrix metalloproteinase-9 concentration in tears collected with a capillary and measured with a rapid immunoassay test.

  20. Change from Baseline in LTA Tear Concentration to the Final Follow-up 1 Month After Final Treatment Session

    Time frame: Baseline up to 1 month after final treatment session

    Measure of lymphotoxin-A in tears collected with a capillary and measured with a rapid immunoassay test.

Study contacts

Contact information is provided by the study sponsor or research team.

James S Wolffsohn, PhD

CONTACT

[email protected]

+441212044400 ext. 3934

Sponsors and collaborators

Lead sponsor

Aston University

Other

Registry information

Official study title

Photobiomodulation of the Ocular Surface and Eyelids With Different Wavelengths: REd vs BluE Light (REBEL)

Important dates

Study start
2024
Primary completion
2026
Study completion
2026
First posted
Apr 17, 2024
Registry last updated
Jan 21, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Related clinical trials

Published trials that share one or more normalized conditions with this study.