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

Naval Hospital, Athens30 enrolled

Overview

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.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

TRIPLE

Enrollment

Conditions

Dry Eye Dry Eye Syndromes

Interventions

laser lightPROCEDURE

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.

Eligibility

Sex: ALLMin age: 18 Years

Medical Language ↔ Plain English

Inclusion criteria were: * 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. Exclusion criteria were: * 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

Locations (2)

Naval Hospital of Athens

Athens, Greece

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

Athens, Greece

Outcomes

Primary Outcomes

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

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.

Secondary Outcomes

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.

Lower Eyelid Tear Meniscus Height

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

Lower Eyelid Tear Meniscus Depth

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

Meibomography

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

Best Corrected Visual Acuity (BCVA)

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

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

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).

corneal staining and the conjunctival injection

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

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)

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).

secretion quality

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

Data from ClinicalTrials.gov

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