RecruitingNCT06371300Updated Jan 21, 2026

Photobiomodulation With REd vs BluE Light (REBEL)

An interventional study of Red LLLT and Blue LLLT in Dry Eye Syndromes, Meibomian Gland Dysfunction and Blepharitis, sponsored by Aston University. Recruiting at 2 sites in 2 countries. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-01-21.

Sponsored by Aston University · Not applicable, Interventional, and Treatment

From the registry’s dates

Started May 2024; still recruiting 2 years 6 months later.

Phase: Not applicable
Study type: Interventional
Enrollment: 36
Allocation: Randomized
Ages: 18 Years and older
Sex: All

Study summary

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.

Read the detailed description

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.

Conditions studied

Dry Eye Syndromes
Meibomian Gland Dysfunction
Blepharitis

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Keywords

Low-level light therapy

In context

Dry Eye Syndromes

1,366 studies on the registry are indexed under Dry Eye Syndromes; 207 are open to participants now.

This study's planned enrollment of 36 is below the median of 60 across 1,129 interventional studies indexed under Dry Eye Syndromes.

Browse Dry Eye Syndromes studies →

Lead sponsor

Aston University is the lead sponsor of 27 studies on the registry; 8 are open to participants now.

Counted across the registry records on this site, refreshed daily.

Who can participate

Ages eligible: 18 Years and older
Sexes eligible: All
Accepts healthy volunteers: No

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

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

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

Study design

Phase: Not applicable
Primary purpose: Treatment
Allocation: Randomized
Intervention model: Parallel assignment
Masking: Triple (Participant, Investigator, Outcomes assessor)
Enrollment: 36 participants (estimated)

Study arms

Active comparator
Red light only group
LLLT will be administered using the Espansione Group Ltd Eye-light unit. LLLT consisting of a wearable facial mask with red light emitting diodes (LEDs) is administered for 30 minutes.
Device: Red LLLT
Experimental
Red plus blue light group
LLLT consisting of a wearable facial mask with red LEDs is administered for 15 minutes, followed by a mask with blue LEDs for another 15 minutes.
Device: Red LLLT · Device: Blue LLLT
Sham comparator
Sham treatment group
Sham treatment will be administered by using facial mask with red LEDs emitting at less than 10% fluence power output for 15 minutes, followed by a mask with blue LEDs emitting at less than 10% fluence power output for another 15 minutes.
Device: Sham Red LLLT · Device: Sham Blue LLLT

Interventions

DeviceRed LLLT
Mask with LEDs emitting at wavelengths of 633nm to facial and eyelids region with their eyes closed
DeviceBlue LLLT
Mask with LEDs emitting at wavelengths of 428nm to facial and eyelid regions with their eyes closed
DeviceSham Red LLLT
Mask with LEDs emitting at wavelengths of 633nm, but with \<10% fluence power output, to facial and eyelids region with their eyes closed
DeviceSham Blue LLLT
Mask with LEDs emitting at wavelengths of 428nm, but with \<10% fluence power output, to facial and eyelids region with their eyes closed

What researchers measure

Primary outcomes

Change from Baseline in Bacterial Colony to the Final Follow-up 1 Month After Final Treatment Session
Measure of number of bacterial colonisation obtained from eyelid swabs
Time frame: Baseline up to 1 month after final treatment session

Secondary outcomes

Change from Baseline in Visual Acuity to the Final Follow-up 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
Time frame: Baseline up to 1 month after final treatment session
Change from Baseline in Non-invasive Tear Break Up Time to the Final Follow-up 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.
Time frame: Baseline and 1 month after final treatment session
Change from Baseline in Blink Rate to the Final Follow-up 1 Month After Final Treatment Session
Manual subjective count of the number of blinks using the Oculus Keratograph 5M instrument.
Time frame: Baseline up to 1 month after final treatment session
Change from Baseline in Tear Meniscus Height to the Final Follow-up 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.
Time frame: Baseline up to 1 month after final treatment session
Change from Baseline in Lipid Layer Pattern Grading to the Final Follow-up 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.
Time frame: Baseline up to 1 month after final treatment session
Change from Baseline in Bulbar Conjunctival Hyperaemia to the Final Follow-up 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.
Time frame: Baseline up to 1 month after final treatment session
Change from Baseline in Limbal Conjunctival Hyperaemia to the Final Follow-up 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.
Time frame: Baseline up to 1 month after final treatment session
Change from Baseline in Blood Flow to the Final Follow-up 1 Month After Final Treatment Session
Measure of blood flow using laser doppler flowmetry instrument.
Time frame: Baseline up to 1 month after final treatment session
Change from Baseline in Saponification Grading to the Final Follow-up 1 Month After Final Treatment Session
Measure of saponification on a scale of 0 (no saponification) to 3 (severe saponification)
Time frame: Baseline up to 1 month after final treatment session
Change from Baseline in Demodex Presence to the Final Follow-up 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.
Time frame: Baseline up to 1 month after final treatment session
Change from Baseline in Number of Blocked or Capped Meibomian Glands to the Final Follow-up 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.
Time frame: Baseline up to 1 month after final treatment session
Change from Baseline in Lid Margin Telangiectasia Grading to the Final Follow-up 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.
Time frame: Baseline up to 1 month after final treatment session
Change from Baseline in Meibum Expressibility to the Final Follow-up 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.
Time frame: Baseline up to 1 month after final treatment session
Change from Baseline in Meibum Quality to the Final Follow-up 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.
Time frame: Baseline up to 1 month after final treatment session
Change from Baseline in Fluorescein Corneal Staining to the Final Follow-up 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.
Time frame: Baseline up to 1 month after final treatment session
Change from Baseline in Bulbar Conjunctival Staining to the Final Follow-up 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.
Time frame: Baseline up to 1 month after final treatment session
Change from Baseline in Lissamine Green Lid Wiper Epitheliopathy to the Final Follow-up 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.
Time frame: Baseline up to 1 month after final treatment session
Change from Baseline in Meibography Meiboscore to the Final Follow-up 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).
Time frame: Baseline up to 1 month after final treatment session
Change from Baseline in MMP-9 Tear Concentration to the Final Follow-up 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.
Time frame: Baseline up to 1 month after final treatment session
Change from Baseline in LTA Tear Concentration to the Final Follow-up 1 Month After Final Treatment Session
Measure of lymphotoxin-A in tears collected with a capillary and measured with a rapid immunoassay test.
Time frame: Baseline up to 1 month after final treatment session

Study locations

1 of 2 sites recruiting

University of Auckland
Auckland, New Zealand
9 other open studies at this site →
Recruiting
- Jennifer P Craig, PhD · Contact · jp.craig@auckland.ac.nz · +6493737599
Recruiting
Aston Dry Eye Clinic
Birmingham, West Midlands B4 7ET, United Kingdom
Completed
Not enrolling at this site.
Completed

References and documents

Publications

Tomlinson A, Bron AJ, Korb DR, Amano S, Paugh JR, Pearce EI, Yee R, Yokoi N, Arita R, Dogru M. The international workshop on meibomian gland dysfunction: report of the diagnosis subcommittee. Invest Ophthalmol Vis Sci. 2011 Mar 30;52(4):2006-49. doi: 10.1167/iovs.10-6997f. Print 2011 Mar. No abstract available. PubMed 21450918 ↗
Pult H, Riede-Pult B. Comparison of subjective grading and objective assessment in meibography. Cont Lens Anterior Eye. 2013 Feb;36(1):22-7. doi: 10.1016/j.clae.2012.10.074. Epub 2012 Oct 27. PubMed 23108007 ↗
Wolffsohn JS, Arita R, Chalmers R, Djalilian A, Dogru M, Dumbleton K, Gupta PK, Karpecki P, Lazreg S, Pult H, Sullivan BD, Tomlinson A, Tong L, Villani E, Yoon KC, Jones L, Craig JP. TFOS DEWS II Diagnostic Methodology report. Ocul Surf. 2017 Jul;15(3):539-574. doi: 10.1016/j.jtos.2017.05.001. Epub 2017 Jul 20. PubMed 28736342 ↗
Schiffman RM, Christianson MD, Jacobsen G, Hirsch JD, Reis BL. Reliability and validity of the Ocular Surface Disease Index. Arch Ophthalmol. 2000 May;118(5):615-21. doi: 10.1001/archopht.118.5.615. PubMed 10815152 ↗
Chalmers RL, Begley CG, Caffery B. Validation of the 5-Item Dry Eye Questionnaire (DEQ-5): Discrimination across self-assessed severity and aqueous tear deficient dry eye diagnoses. Cont Lens Anterior Eye. 2010 Apr;33(2):55-60. doi: 10.1016/j.clae.2009.12.010. Epub 2010 Jan 25. PubMed 20093066 ↗
Arita R, Minoura I, Morishige N, Shirakawa R, Fukuoka S, Asai K, Goto T, Imanaka T, Nakamura M. Development of Definitive and Reliable Grading Scales for Meibomian Gland Dysfunction. Am J Ophthalmol. 2016 Sep;169:125-137. doi: 10.1016/j.ajo.2016.06.025. Epub 2016 Jun 23. PubMed 27345733 ↗

Individual participant data

Plan to share: Yes — Deidentified datasets will be available upon request.

Time frame: Deidentified datasets will be available upon request.

Access criteria: Deidentified datasets will be available upon request.

Timeline

Tracking since Sep 25, 2026

ElapsedEstimatedEstimated, not yet reachedSimilar studies: half by the dot; the band is the middle halfHalf of similar studies reached it by the dot; the band is the middle half, from a quarter to three quarters

Started May 2024 (actual). Primary completion is estimated for Oct 2026, 29 months after the start.

Of 199 non-industry interventional studies with no phase under Dry Eye Syndromes, half reached primary completion within 12 months of starting (the median), counting those still running; a quarter within 5 and three quarters within 25. This study's planned 29 months is above that.

Counting every sponsor, half of 312 studies reached it within 10 months; a quarter within 4 and three quarters within 18.

How these figures are worked out, and which studies are left out of them.

Registered: Apr 15, 2024
First posted: Apr 17, 2024
StartActual: May 1, 2024
Primary completionEst.: Oct 30, 2026
CompletionEst.: Dec 30, 2026
Last update: Jan 21, 2026

What these dates mean

Start.: When the first participant enrolled; while estimated, when the study expects to open to recruitment.
Primary completion.: When the last participant was examined or treated to collect data for the study's main question, its primary outcome. A study that stopped early gives the date its data collection stopped.
Completion.: When the last participant's last visit took place, for every outcome, secondary ones and side effects included: the end of the study. Often later than primary completion, sometimes the same day.
Actual and Est.: Actual means the registry says the date has happened. Est. (estimated) is a date the sponsor plans or expects. It can still move, and the sponsor is expected to change it to actual once it has passed.

No changes since tracking began. The registry record was last updated on Jan 21, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗

Registry details

Key details

Study ID: NCT06371300
Lead sponsor: Aston University
Responsible party: Sponsor
First posted: Apr 17, 2024
Start date: May 1, 2024
Primary completion: Oct 30, 2026 (estimated)
Completion: Dec 30, 2026 (estimated)
Last update: Jan 21, 2026

Study contacts

James S Wolffsohn, PhD

Contact

j.chiang@aston.ac.uk

+441212044400 ext. 3934

James S Wolffsohn, PhD

study director · Aston University

Oversight

Data monitoring committee: No
FDA-regulated drug: No
FDA-regulated device: No

View the source record on ClinicalTrials.gov ↗

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