A Review of Applications and Intracellular Mechanisms of Intense Pulsed Light in Eyelid Inflammatory Diseases.

To evaluate relevant clinical outcomes and conclude possible mechanisms of intense pulsed light (IPL) in eyelid inflammation. IPL devices were primarily applied in cutaneous vascular malformations and have been used in ocular diseases for about 20 years, mostly including meibomian gland dysfunction (MGD), blepharitis, and ocular rosacea. Seventy-two original clinical researches were included, 57 for MGD, 4 for blepharitis or blepharitis-related keratoconjunctivitis, and 11 for rosacea. Dry eye symptoms, (tear) break-up time (BUT), and meibomian structure and/or functions were improved in most patients, but production of reactive oxygen species is an important link in the photobiomodulation mediated by IPL, which can influence numerous signal pathways to achieve anti-inflammatory, anti-infective, and prodifferentiation effects. The evidence suggests that IPL is an effective therapeutic tool for most patients with MGD, but more clinical evidence is needed for other indications.