关键词: 痤疮, 瘢痕, 激光, 皮秒激光, CO2点阵激光

Abstract: 【Abstract】 Objective To compare the efficacy and safety of picosecond alexandrite laser and ultrapulsed fractional CO2 laser for the treatment of facial atrophic acne scars in a prospective, split-face clinical trial. Methods From October 2015 to October 2017, patients with facial symmetrical atrophic acne scars were enrolled from Department of Cosmetic Laser Surgery, Hospital for Skin Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College. The left side of the face of the patients was treated with ultrapulsed fractional CO2 laser, and the right side of the face was treated with a 755-nm picosecond alexandrite laser with a diffractive lens array. All patients received 3 sessions of laser treatment at a 2-month interval. The severity of scars was evaluated by 2 dermatologists before and after the treatment according to the ECCA grading scale （échelle d′évaluation clinique des cicatrices d′acné）, and clinical efficacy was self-assessed by the patients according to a 4-point scale. Pain scores and adverse reactions were recorded. Paired t test was used to compare ECCA scores and pain scores between the 2 sides of the face, as well as between pre- and post-treatment values, and Wilcoxon rank sum test was used to compare the 4-point scores between the 2 groups. Results There was no significant difference in the ECCA score between the picosecond laser side and the fractional laser side before the treatment （t = 1.06, P = 0.300）, while the ECCA score was significantly higher in the picosecond laser side than in the fractional laser side after 3 sessions of treatment （70.98 ± 21.48 vs. 58.04 ± 17.63, t = 3.76, P = 0.001）. Compared with the pre-treatment severity score of scars, the improvement in severity score was significantly less in the picosecond laser side than in the fractional laser side （2.21 ± 1.09 vs. 2.83 ± 1.11, z = 2.70, P = 0.007）. Compared with the fractional laser side, the picosecond laser side showed significantly lower pain scores （3.71 ± 0.62 vs. 6.23 ± 1.06, t = 11.93, P < 0.001） and less adverse reactions, which mainly manifested as transient erythema and edema. Conclusions Both picosecond alexandrite laser and fractional CO2 laser can effectively improve atrophic acne scars. Fractional CO2 laser is more effective, but picosecond alexandrite laser has less adverse effects.

Key words: Acne, Cicatrix, Lasers, Picosecond laser, Fractional CO2 laser