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Dry EyeNCT04425551

Effect of Micropulse Laser on Dry Eye Disease Due to Meibomian Gland Dysfunction

A study testing laser light in people with Dry Eye and Dry Eye Syndromes, run by Naval Hospital, Athens at 2 sites in Greece.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

The modern treatment of meibomian gland dysfunction(MGD) is based on anti-inflammatory drops or oral antibiotics for decreasing dry eye disease (DED) associated inflammation, warm compresses for liquefying the thicker meibum, and lid hygiene for reducing the bacterial overload. Read more about this study

Who is it for?
Ages 18 years and older
What is being tested?
laser light
Type of treatment
Surgery or procedure
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
30 participants
Where
2 sitesGreece
Study dates
6 Dec 2022to 18 Jul 2025
Phase
Interventional
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 years and older
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • chief complaint of at least one of the following symptoms: dryness, foreign-body sensation, burning, and tearing for 3 months
  • diagnosis of DED secondary to MGD with eyelid margin telangiectasias in both eyes
  • a baseline Ocular Surface Disease Index (OSDI) score ≥ 40
  • tear break-up time (TBUT) ≤ 5 seconds
  • corneal fluorescein staining ≥ 6 as per the National Eye Institute (NEI) grading scale for corneal staining.

Who cannot join

  • history of ocular trauma or surgery
  • use of any treatment for DED or MGD other than artificial tears within the past 3 months
  • active allergy, infection, or inflammatory disease at the ocular surface unrelated to DED or MGD
  • lacrimal drainage system anomalies
  • contact lens wear
  • use of any systemic or topical anti-inflammatory medicine

Trial locations and contacts

2 sites in 1 country.

Greece2 sites

  • Naval Hospital of Athens

    Athens, 11521

  • First Department of Ophthalmology, National and Kapodistrian University of Athens, Athens, Greece

    Athens

Other trials in Greece

About this study

Official title: Prospective Study of the Effect of Micropulse Laser on Dry Eye Disease Due to Meibomian Gland Dysfunction

The modern treatment of meibomian gland dysfunction(MGD) is based on anti-inflammatory drops or oral antibiotics for decreasing dry eye disease (DED) associated inflammation, warm compresses for liquefying the thicker meibum, and lid hygiene for reducing the bacterial overload. But, such treatments have shown limited effectiveness to a large proportion of patients with MGD, due to the multifactorial background of the disease. Thus, alternative approaches aiming at different aspects of the DED pathophysiology are needed.

Elimination of posterior lid-margin hyperemia with telangiectasia could be a treatment target for reducing the secretion of inflammatory mediators in the course of MGD. Using the mechanism of photocoagulation via selective thermolysis, laser light could contribute to the destruction of abnormal vessels at the posterior lid-margin and thus, the reduction of inflammation. Recently, sub-threshold (micropulse) laser photocoagulation was introduced in ophthalmology and offers significant clinical advantages compared to conventional continuous wave (CW) approach, preventing laser induced thermal damage and related treatment side effects.

This study investigates the effect of sub-threshold (micropulse) laser treatment for dry eye disease due to meibomian gland dysfunction combined with increased eyelid margin vascularity.

Being tested
laser light, Sham treatment
Keywords
dry eye, meibomian gland dysfunction, subthreshold laser, telangiectasia, eyelid margin vascularity
Medical subject headings
Dry Eye Syndromes, Meibomian Gland Dysfunction, Telangiectasis

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • laser lightProcedure or surgery

    laser photocoagulation of the telangiectatic vessels of the lower eyelid margin with a slit lamp-based 532 nm optically pumped dual- diode solid-state subthreshold (SP-Mode) laser system

  • Sham treatmentDevice

    Sham treatment replicated all procedural steps (eyelid eversion, stabilization, slit-lamp aiming, equivalent spot count) using identical laser settings, but with minimal power (50 mW, duration 10 ms) and beam offset to the adjacent non-vascular periorbital skin, ensuring no energy delivery to eyelid margin vessels, and preserving the device operational sound, laser light, and foot pedal activation. No laser energy was delivered to eyelid margin vasculature in the sham treatment, and no visible tissue reaction or blanching was observed during the procedure. The anesthesia and cleaning procedures were identical.

Study groups in NCT04425551
Study groupRoleWhat they receive
Laser GroupActive comparatorThe treatment involved laser photocoagulation of the telangiectatic vessels of the lower eyelid margin with a slit lamp-based 532 nm optically pumped dual- diode solid-state subthreshold (SP-Mode) laser system (LightLas TruScan Pro 532 nm, LightMed Corporation, San Clemente, CA, USA). The laser settings were selected to induce vascular photocoagulation without visible tissue blanching or epithelial disruption. The subthreshold treatment parameters were set at 50 μm spot size and duration of 200 ms with duty cycle of 20%. Laser power was titrated in mono-spot micropulse mode starting at 500 mW and increased in 100 mW steps, until focal blanching without epithelial whitening, maximum 1500 mW. The treatment endpoint was defined as immediate focal blanching (disappearance of the red reflex) of the target telangiectatic vessel, assessed under a high-magnification slit-lamp view, with the effect confined to the targeted vessel and no visible impact on adjacent tissue.
Receives: Procedure: laser light
Control GroupPlacebo comparatorSham treatment replicated all procedural steps (eyelid eversion, stabilization, slit-lamp aiming, equivalent spot count) using identical laser settings, but with minimal power (50 mW, duration 10 ms) and beam offset to the adjacent non-vascular periorbital skin, ensuring no energy delivery to eyelid margin vessels, and preserving the device operational sound, laser light, and foot pedal activation. No laser energy was delivered to eyelid margin vasculature in the sham treatment, and no visible tissue reaction or blanching was observed during the procedure. The anesthesia and cleaning procedures were identical.
Receives: Device: Sham treatment

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Tear Break Up Time (TBUT)

    Using a slit-lamp biomicroscope with cobalt blue illumination, the time interval between the last complete blink and first appearance of a dark dry spot on the corneal surface was measured using a digital stopwatch. The test was repeated three times consecutively, and the mean TBUT was recorded

    Measured: The subjects were evaluated at five different time points: (a) 1 day preoperatively (baseline), (b) 2 weeks (W2), (c) 4 weeks (W4), (d) 8 weeks (W8), and (e) 12 weeks (W12) postoperatively.

Secondary outcomes (11)

  1. Ocular Surface Disease Index (OSDI)

    The scoring system ranges from 0 to 100 and categorizes the ocular surface condition into normal (0-12), mild (13-22), moderate (23-32), or severe dry eye (≥ 33).15 OSDI questionnaire was administered once per patient to assess subjective symptom severity at each visit, whereas all other parameters were evaluated separately for each eye.

    Measured: The subjects were evaluated at five different time points: (a) 1 day preoperatively (baseline), (b) 2 weeks (W2), (c) 4 weeks (W4), (d) 8 weeks (W8), and (e) 12 weeks (W12) postoperatively.

  2. Lower Eyelid Tear Meniscus Height

    height (μm) via Anterior Segment Swept-Source Optical Coherence Tomography

    Measured: The subjects were evaluated at five different time points: (a) 1 day preoperatively (baseline), (b) 2 weeks (W2), (c) 4 weeks (W4), (d) 8 weeks (W8), and (e) 12 weeks (W12) postoperatively.

  3. Lower Eyelid Tear Meniscus Depth

    depth (μm) via Anterior Segment Swept-Source Optical Coherence Tomography

    Measured: The subjects were evaluated at five different time points: (a) 1 day preoperatively (baseline), (b) 2 weeks (W2), (c) 4 weeks (W4), (d) 8 weeks (W8), and (e) 12 weeks (W12) postoperatively.

  4. Meibomography

    scale (0,1,2,3). Higher values represent greater disability.

    Measured: The subjects were evaluated at five different time points: (a) 1 day preoperatively (baseline), (b) 2 weeks (W2), (c) 4 weeks (W4), (d) 8 weeks (W8), and (e) 12 weeks (W12) postoperatively.

  5. Best Corrected Visual Acuity (BCVA)

    using Snellen charts, which was converted to logMAR values for statistical analysis purposes.

    Measured: The subjects were evaluated at five different time points: (a) 1 day preoperatively (baseline), (b) 2 weeks (W2), (c) 4 weeks (W4), (d) 8 weeks (W8), and (e) 12 weeks (W12) postoperatively

  6. Schirmer test

    under topical anesthesia standardized Schirmer strips were gently inserted into the lateral third of the lower eyelid margin, and the length of wetting (in millimeters) on the strip was recorded after 5 minutes

    Measured: The subjects were evaluated at five different time points: (a) 1 day preoperatively (baseline), (b) 2 weeks (W2), (c) 4 weeks (W4), (d) 8 weeks (W8), and (e) 12 weeks (W12) postoperatively.

  7. Eyelid margin vascularity

    via slit-lamp biomicroscopy and graded on a 4-point scale as 0 (no visible telangiectasia), 1 (mild telangiectasia with few dilated vessels), 2 (moderate telangiectasia with several visible vessels), and 3 (severe telangiectasia with numerous engorged vessels and marked redness).

    Measured: The subjects were evaluated at five different time points: (a) 1 day preoperatively (baseline), (b) 2 weeks (W2), (c) 4 weeks (W4), (d) 8 weeks (W8), and (e) 12 weeks (W12) postoperatively.

  8. corneal staining and the conjunctival injection

    using fluorescein dye, according to the National Eye Institute (NEI) scale

    Measured: The subjects were evaluated at five different time points: (a) 1 day preoperatively (baseline), (b) 2 weeks (W2), (c) 4 weeks (W4), (d) 8 weeks (W8), and (e) 12 weeks (W12) postoperatively

  9. Conjunctivochalasis

    graded by the number and height of conjunctival folds using a slit lamp as 0 (no persistent folds), 1 (one small fold), 2 (two or more folds not higher than the tear meniscus), and 3 (multiple folds higher than the tear meniscus)

    Measured: The subjects were evaluated at five different time points: (a) 1 day preoperatively (baseline), (b) 2 weeks (W2), (c) 4 weeks (W4), (d) 8 weeks (W8), and (e) 12 weeks (W12) postoperatively.

  10. Meibomian gland (MG) expressibility

    by applying standardized digital pressure to the central third of the lower lid, graded as 1 (light), 2 (moderate), or 3 (heavy pressure required).

    Measured: The subjects were evaluated at five different time points: (a) 1 day preoperatively (baseline), (b) 2 weeks (W2), (c) 4 weeks (W4), (d) 8 weeks (W8), and (e) 12 weeks (W12) postoperatively.

  11. secretion quality

    0 (clear), 1 (cloudy), 2 (granular), or 3 (toothpaste-like).

    Measured: The subjects were evaluated at five different time points: (a) 1 day preoperatively (baseline), (b) 2 weeks (W2), (c) 4 weeks (W4), (d) 8 weeks (W8), and (e) 12 weeks (W12) postoperatively

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted11 Jun 2020
  2. Study start6 Dec 2022
  3. Primary completion3 Apr 2025
  4. Study completion18 Jul 2025

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Parallel groups
Model description
Please note that there was one group of participants, but two groups of eyes (treated/untreated). Thus, PARALLEL was selected, referring to eyes, not participants
Masking
Triple blind
Who is masked
Participant, Investigator, Outcomes assessor
Enrolment
30 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT04425551
Sponsor's protocol ID
6/19
Status last verified
Dec 2025
First submitted
4 Jun 2020
Last updated
2 Jan 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Publications

  • Kappos N, Georgalas I, Papaconstantinou D, Droutsas K. Focal Subthreshold Laser Photocoagulation of Eyelid Margin Vascularity in Telangiectatic Meibomian Gland Dysfunction. Cornea. 2026 Apr 7. doi: 10.1097/ICO.0000000000004161. Online ahead of print.

    PubMed 41960977

Questions about this trial

What is this clinical trial studying?

A study testing laser light in people with Dry Eye and Dry Eye Syndromes, run by Naval Hospital, Athens at 2 sites in Greece.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 5 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 2 Jan 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 2 sites in Greece. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Tear Break Up Time (TBUT) (time frame: The subjects were evaluated at five different time points: (a) 1 day preoperatively (baseline), (b) 2 weeks (W2), (c) 4 weeks (W4), (d) 8 weeks (W8), and (e) 12 weeks (W12) postoperatively.). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT04425551, which also lists 1 linked publication.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 2 Jan 2026.

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