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

Naval Hospital, Athens

Status: Completed

Conditions: Dry Eye; Meibomian Gland Dysfunction; Dry Eye Syndromes

Treatments: Device: Sham treatment; Procedure: laser light

Study type: Interventional

Funder types: Other

Identifiers

NCT04425551

6/19

Details and patient eligibility

About

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.

Enrollment: 30 patients

Sex: All

Ages: 18 to 80 years old

Volunteers: No Healthy Volunteers

Inclusion and exclusion criteria

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

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Triple Blind

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30 participants in 2 patient groups, including a placebo group

Laser Group

Active Comparator group

Description:

The 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.

Treatment:

Procedure: laser light

Control Group

Placebo Comparator group

Description:

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.

Treatment:

Device: Sham treatment