Laser and light-based therapies combined with topical agents for melasma: A systematic review and meta-analysis

This comprehensive review aimed to evaluate the efficacy and safety of combining laser or light therapy with topical agents for melasma treatment.

A comprehensive search was conducted utilizing PubMed, NCBI, Google Scholar, ScienceDirect, Wiley, Embase, and the Cochrane Library. The search aimed to identify pertinent studies from the database's inception until August 31, 2024. This research encompassed 11 randomized controlled trials including 461 people. The melasma area and severity index and its modified variant (mMASI) were employed for outcome assessment. The Cochrane risk-of-bias tool was used to assess study quality. The GRADE (grading of recommendations assessment, development and evaluation) approach was employed to assess the certainty of evidence. Sensitivity analyses were performed to evaluate the robustness of findings. Data were analyzed using RevMan 5.4.1.

Combination therapy demonstrated no significant benefit at 4 weeks, but statistically significant improvements at 8, 12, and 16 weeks (standardized mean difference [SMD]: -0.55; 95% confidence interval: -0.74 to -0.36; P < .00001), indicating a cumulative therapeutic effect. Moderate heterogeneity was observed (I2 = 64%). Sensitivity analysis excluding parallel-design studies (Souza, Bansal, Verma, Qu) confirmed the robustness of efficacy outcomes, with a similar effect size (SMD: -0.45) and reduced heterogeneity (I2 ≈ 41%). Safety analysis showed a significantly higher risk of adverse events in the combination group (OR: 8.96; 95% confidence interval: 3.71-21.64), mainly erythema and post-inflammatory hyperpigmentation. The certainty of evidence was rated as moderate for efficacy and very low for safety outcomes. Both were judged critically important (importance score 9 and 8, respectively) for clinical decision-making.

These findings suggest that combination therapy can effectively enhance melasma treatment. However, careful patient selection and monitoring are crucial due to the risk of side effects. Further large-scale studies with standardized protocols are recommended to validate these findings and optimize treatment strategies.