Effectiveness and Safety of Intense Pulsed Light in Patients With Meibomian Gland Dysfunction

Meibomian gland dysfunction (MGD) is one of the most common causes of dry eye diseases. Over the past decade, several treatment options in MGD have been extensively studied including warm compression, lid hygiene, ocular lubricants, forceful expression, LipiFlow thermal pulsation system, intraductal probing, debridement scaling and intense pulsed light (IPL). IPL is a broad spectrum, non-coherent and polychromatic light source with a wavelength spectrum of 500-1200 nm. It can be filtered to allow only a range of wavelengths to be emitted. Different wavelength makes different depth of tissue to absorb a specific light energy. Intense pulsed light (IPL) has been widely used in dermatology as a therapeutic tool for removal of hypertrichosis, benign cavernous hemangioma, benign venous malformations, telangiectasia, port-wine stain and pigmented lesions. Concurrent ocular surface improvements have been observed in patients undergone IPL treatment. Very few prospective clinical trials showed that subjective dry eye symptoms decreased and some of the dry eye signs also improved. Nonetheless, there is still inconsistency in the efficacy of IPL among these studies. Biomarkers, specifically cytokines, in dry eye diseases have been studied to some extent. Moreover, the change in ocular surface inflammatory cytokines in patients with MGD after IPL treatment is unclear. The investigators proposed a prospective randomized double-masked sham-controlled clinical trial to investigate the efficacy and safety of intense pulse light in MGD patients.