Dual Effect of Photobiomodulation on Melasma: Downregulation of Hyperpigmentation and Enhanced Solar Resistancea??A Pilot Study

摘要

Overview. Melasma is a resistant, sun-induced facial hyperpigmentation capable of remaining present for decades with ensuing psychological distress. Treatment is difficult and focuses on an array of measures to reduce skin hyperpigmentation resulting from triggered hyperactive melanocytes. The pathogenesis of melanoma is not clearly understood but it has been reported that some growth factors and specific cell-signaling pathways are involved. Objective. The objective of the current study was to evaluate the use of pulsed photobiomodulation to modulate melasma via the regulation of gene expression pertaining to skin pigmentation. Methods. We evaluated a two-step approach via a spilt-face pilot study involving seven patients with bilateral dermal melasma who had formerly undergone unsuccessful treatments. During treatment, the initial mobilization phase with microdermabrasion was closely followed by the modulation phase, delivering low-energy pulsed photons (940nm) to downregulate highly metabolic melanocytes in the dermis. A weekly treatment was performed for eight consecutive weeks. White light pictures, ultraviolet pictures, melanin index scores, and Melasma Area and Severity Index scores were obtained at baseline and at Week 12. Results. The pulsed photobiomodulation-treated side versus the control side showed statistically significant results for pigment reduction. Conclusion. This pilot study shows that dermal melasma can be significantly improved with pulsed photobiomodulation. Interestingly, it might also precondition the skin, helping it to build a resistance to future solar ultraviolet ray exposure.