Comparative Efficacy and Safety of 1064‐nm Picosecond Laser and 1927‐nm Fractional Thulium Laser for Atrophic Acne Scars in Asian Patients: A Prospective, Randomized, Split‐Face Study

BACKGROUND: Atrophic acne scars are a common sequela of inflammatory acne, resulting from abnormal dermal remodeling due to imbalance in collagen synthesis and degradation. Laser therapies, including picosecond and fractional lasers, have emerged as effective treatments, yet direct comparative studies remain limited. OBJECTIVE: To compare the efficacy, safety, and tolerability of 1064-nm microlens array picosecond laser (P-MLA) versus 1927-nm sub-ablative fractional thulium laser (FTL) in Asian patients with atrophic acne scars. METHODS: This prospective, single-center, evaluator-blinded, randomized trial employed a split-face design. Thirty-five patients with symmetric facial atrophic acne scars received three sessions of P-MLA on one side and FTL on the contralateral side at 4-week intervals. Clinical outcomes were assessed using ECCA scores and blinded physician GAIS. Objective skin parameters (TEWL, MI, and EI) were measured, and patient satisfaction and adverse events were recorded. RESULTS: Both lasers significantly improved ECCA scores compared to baseline (P-MLA: 102.86 ± 47.47 → 86.86 ± 47.42, p < 0.001; FTL: 101.43 ± 44.89 → 85.57 ± 50.54, p < 0.001), with no significant difference between sides. GAIS score was significantly higher on the P-MLA side (2.83 ± 1.272 vs. 2.57 ± 1.243, p = 0.037). P-MLA demonstrated lower MI and EI at 3 months post-treatment, reduced intraoperative pain, shorter crusting duration, and minimal social downtime, whereas FTL exhibited higher crusting and erythema. TEWL returned to baseline for both groups. Patient satisfaction was high and comparable between sides. CONCLUSION: Both P-MLA and FTL are effective for treating atrophic acne scars in Asian patients, demonstrating comparable clinical efficacy.