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

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.

Each participant's clinically worse eye was selected for treatment, while the other eye was observed as control. If both eyes were clinically same, one of them was randomly selected. *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

The lower eyelid margin of the clinically worse eye was selected for treatment. A slit lamp based 532 nm optically pumped dual diode solid state SP-Mode (subthreshold) laser system was used. After cleaning eyelids with a cosmetic face wash, a drop of proparacaine hydrochloride 0.5% was then administered onto the conjunctival sac. No eye or cornea shield was used, since laser light was directly aimed at telangiectasias. The treatment parameters were set with 50 μm spot size and 200 ms duration with 30% duty cycle. The power ranged from 1500 to 1700 mW with monospot micropulse model and a just visible destruction of the telangiectatic vessels served as the threshold burn. After the procedure, the patient received corticosteroid ointment for 5 days on both eyes and was advised to continue applying her pre-treatment medication on both eyes.

Lower Eyelid Margin Vascularity is measured with ImageJ® software for vessels analysis from photographs of lower eyelid margin. Vascularity is evaluated as percentage (%) of lower eyelid margin surface. Time points are referred at ''Time Frame'' section.

Baseline, Day 0 after treatment, Day 14 after treatment, Day 30 after treatment, Day 60 after treatment

Inclusion Criteria: 18-80 years chief complaint of more than one of dryness, foreign-body sensation, burning, and tearing for 3 months diagnosis of MGD with palpebral telangiectasia in both eyes Exclusion Criteria: ocular structural abnormalities history of ocular trauma or surgery use of any treatment for DE or MGD, other than artificial tears, within the past month active allergy, infection, or inflammatory disease at the ocular surface unrelated to DE or MGD lacrimal drainage-system anomalies contact-lens wear use of any systemic anti-inflammatory medicine