Efficacy of Combination Therapy With Fractional Carbon Dioxide Laser and Ultraviolet B Phototherapy for Vitiligo: A Systematic Review and Meta-Analysis

Vitiligo is a common cutaneous depigmentation disease. Various treatment modalities are available for vitiligo. Phototherapy with ultraviolet B (UVB) is one of the first-line therapies for extensive vitiligo; it induces melanocyte differentiation and melanin production.1 However, a high proportion of patients with vitiligo still have refractory disease.2,3 Previous systematic reviews and meta-analyses have suggested that the fractional carbon dioxide (CO2) laser is an effective adjuvant therapy to various treatment modalities for vitiligo.2-4 However, other studies published since then have shown conflicting results regarding the additive effects of the laser. In this study, we evaluated the efficacy of the fractional CO2 laser as a combination treatment to UVB phototherapy in repigmentation of vitiligo by performing an updated systematic review and meta-analysis. One author (H.C.C.) performed a systematic search of databases (on July 21, 2019), including PubMed, Embase, Web of Science, and Cochrane Library, for head-to-head studies investigating the efficacy of the combination therapy of fractional CO2 laser and UVB phototherapy (intervention group) vs UVB phototherapy alone (control group) for vitiligo. Studies focusing on UVB phototherapy alone were excluded. Two authors (H.C.C. and M.H.L.) extracted data from eligible studies individually. The primary outcome was the repigmentation rates of vitiligo. Risk of bias 2.0 (RoB 2.0) tool was employed for evaluation of the quality of randomized controlled trials (RCTs) by 2 independent authors. Disagreements between reviewers were resolved through discussion with a senior author (H.H.T.). A random-effects model was utilized for pooled analyses, and data were assessed by estimating the risk ratio (RR) with 95% confidence interval (CI). Heterogeneity across studies was assessed with the Χ2 statistic and I2 statistic, and publication bias was evaluated utilizing Egger's test. Statistical significance was defined as P < 0.05. All statistical analyses were performed with Comprehensive Meta-Analysis 3.0 (Biostat, Englewood, NJ).