About this trial
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.
Eligibility criteria
This trial does not accept healthy volunteersQualifiers
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
Disqualifiers
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
Trial design
Parallel
Treatments tested in this trial
Red LLLT
DeviceMask with LEDs emitting at wavelengths of 633nm to facial and eyelids region with their eyes closed
Blue LLLT
DeviceMask with LEDs emitting at wavelengths of 428nm to facial and eyelid regions with their eyes closed
Sham Red LLLT
DeviceMask 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
DeviceMask with LEDs emitting at wavelengths of 428nm, but with \<10% fluence power output, to facial and eyelids region with their eyes closed
Treatment groups
Trial outcomes
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
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
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.
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.
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.
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