Lower-fluence, higher-density versus higher-fluence, lower-density treatment with a 10,600-nm carbon dioxide fractional laser system: A split-face, evaluator-blinded study

Background Adequate laser settings in the treatment of scars using a carbon dioxide fractional laser system (CO₂ FS) have not been established. Objective To compare the efficacy and safety of low-fluence, high-density with high-fluence, low-density treatment with CO₂ FS on acne scars and enlarged pores. Methods Ten patients with mild to severe atrophic acne scars and enlarged pores were enrolled. Half of each subject's face was treated with a single session of CO₂ FS with a fluence of 70 mJ and a density of 150 spots/cm²; the other half was treated with a fluence of 30 mJ and a density of 250 spots/cm². Results Follow-up results 3 months after a single low-fluence, high-density treatment with CO₂ FS showed that four of 10 participants had clinical improvement of 51% to 75% from baseline. After the high-fluence, low-density CO₂ FS treatment, five of 10 patients demonstrated marked clinical improvements of more than 76%. Conclusion Higher-energy, lower-density laser settings seem to be more effective than lower-energy, higher-density settings for acne scars and enlarged pores, although our results do not constitute a conclusive comparison of the two different modes of CO₂ FS.