Q-switched lasers provide a short pulse duration with a higher energy intensity. QS lasers that target melanin include the Ruby, Alexandrite and Nd:YAG. Initial studies were somewhat disappointing as the majority of patients experienced significant post-inflammatory hyperpigmentation and worsening melasma. A newer technique called low fluence QS laser is now being studied at the 1064 nm wavelength, with promising results.4 Wattanakrai et al. found an improvement of 92.5% after five consecutive weekly sessions with the low fluence QS Nd:YAG in a split face study. However, hypopigmentation was a common side effect and, unfortunately, there was a 100% recurrence rate. Two separate studies by Xi and Hofbauer Parra have found similar recurrence rates.
More recently, a newer class of lasers called picosecond lasers with even shorter pulse duration have been studied. The thought is that with a shorter pulse duration, there is more of subthermolytic photoacoustic damage that can selectively target pigment without destroying or excessively heating the surrounding tissue.5 There have been only a handful
of case reports using this laser modality in melasma. However, theoretically it seems to represent a potential treatment alternative for melasma with less cutaneous side effects such as dyspigmentation. This could be particularly true if used in combination with topical therapy, or if used with a fractionated handpiece for combination with laser-assisted drug delivery of a variety of bleaching agents.
In conclusion, melasma is a notoriously hard-to-treat condition. The treatment should be personalized to each individual. The most successful approaches tend to rely on the combination of sunscreen, lightening topical products (hydroquinone, tranexamic acid, kojic acid, glycolic acid, retinoic acid, superficial chemical peels), laser/light therapy and, sometimes, even oral tranexamic acid. In our practice, we use IPL, low fuence 1927nm and picosecond treatments with variable success. However, the decision of whether to laser is still up for argument — given the high recurrence rates and the lack of blinded studies — lasers should be used as second line therapy only after a rigid topical regimen has been tried.
1. Sarkar, R, et al. Melasma in Men: A Review of Clinical, Etiological, and Management Issues. J Clin Aesthet Dermatol. 2018 Feb;11(2):53-59
2. Sarkar, R, et al. Lasers in Melasma: A Review with Consensus Recommendations by Indian Pigmentary Expert Group. Indian J Dermatol. 2017 Nov-Dec; 62(6): 585–590
3. Kim EH, et al. The vascular characteristics of melasma. J Dermatol Sci. 2007;46:111–116
4. Trivedi MK. A review of laser and light therapy in melasma. Int J Womens Dermatol. 2017 Mar; 3(1): 11–20
5. Liu T. Photoacoustic generation by multiple picosecond pulse excitation. Med Phys. 2010 Apr;37(4):1518-21