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

NCT ID: NCT04425551

Last Updated: 2025-12-30

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 30 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2022-12-06
• Study Completion Date: 2025-07-18

Brief 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. 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.

Conditions

Dry Eye; Dry Eye Syndromes; Meibomian Gland Dysfunction

Keywords

dry eye; meibomian gland dysfunction; subthreshold laser; telangiectasia; eyelid margin vascularity

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: TRIPLE

Study Groups

Laser Group

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.

Group Type: ACTIVE_COMPARATOR

laser light

Intervention Type: PROCEDURE

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

Control Group

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.

Group Type: PLACEBO_COMPARATOR

Sham treatment

Intervention Type: DEVICE

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.

Interventions

laser light

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

Intervention Type: PROCEDURE

Sham treatment

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.

Intervention Type: DEVICE

Eligibility Criteria

Inclusion Criteria

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

Exclusion Criteria

14 Exclusion criteria were: (a) history of ocular trauma or surgery; (b) use of any treatment for DED or MGD other than artificial tears within the past 3 months; (c) active allergy, infection, or inflammatory disease at the ocular surface unrelated to DED or MGD; (d) lacrimal drainage system anomalies; (e) contact lens wear; and (f) use of any systemic or topical anti-inflammatory medicine. These criteria were selected to ensure a homogeneous cohort with vascular MGD and eliminate confounding factors that could influence tear production or corneal staining.

• Minimum Eligible Age: 18 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

National and Kapodistrian University of Athens

OTHER

Sponsor Role: collaborator

Naval Hospital, Athens

OTHER

Sponsor Role: lead

Responsible Party

Nikolaos Kappos

Ophthalmologist Surgeon, Clinical Investigator

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Nikolaos Kappos, MD

Role: PRINCIPAL_INVESTIGATOR

Naval Hospital, Athens

Locations

Naval Hospital of Athens

Athens, , Greece

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

Athens, , Greece

Countries

Greece

Other Identifiers

6/19

Identifier Type: -

Identifier Source: org_study_id