Efficacy And Safty Profile Of Q-switched Nd:YAG Laser For The Treatment Of Melasma

Background Melasma is a kind of common pigmentary disorder that affects all skin types especially in Fitzpatrick skin typesâ…£-â…¥.However,safe and effective treatment of melasma still needs to be explored.Proved effective for pigmentary disorder,laser has been applied to melasma in recent years.Objective To evaluate the efficacy and safety profile of Q-switched(QS) 1064nm Nd:YAG laser for the treatment melasma.Methods A total of 50 patients were recruited,including 47 female patients and 3 male patients.All were treated with QS Nd:YAG laser at low energy level weekly for a total of 10 sessions.Follow up visit was carried out at 6 months after treatment,and recurrence rate and degree were evaluated.Digital photographs were taken before treatment and at each subsequent visit.Melanin index(MI)was measured by Mexameter before each treatment.A dermatologist not involved in the study evaluated Melasma Area and Severity Index Score(MASI) for each subjects during the whole process.Patients were inquired of their satisfaction to the treatment at the end of the study.We also performed Confocal laser scanning microscope(CLSM) for several patients at baseline and the end of 10 sessions of treatments.Statistical analysis was performed to evaluate clinical response and factors relate to therapeutic outcome.Results Of the 50 melasma patients,42 people(84%) achieved more than 50% improvement,of whom 27 people(54%) achieved 75%-100%clearance,and 3 of them achieved 100%clearance.CLSM test findings proved melanin decrease in the treated regions,suggesting QS Nd:YAG laser can inhibit melanocyte function.Mean MI decreased with the ongoing of treatment,and significant decrease of mean MI was showed after the 3^rd session(P=0.019).MASI decreased significantly(P=0.000) after treatment.Multiple liner regression indicated that therapeutic outcome depended on disease severity(P=0.001,R=0.494) at the basline.Recurrence rate at 6 months after the final session of treatment was 69%.There were hardly any other severe adverse effects.Conclusion QS Nd:YAG 1064nm laser is effective and safe for the treatment of melasma,however,further studies are still required to explore it's mechanisms and prevent recurrence.