Objective: To compare and analyze the effects of Er:YAG laser treatment in the microlaser peeling, fractional ablative laser, or combined modes for the treatment of concave acne scars.

Method: Ninety patients of concavity acne scar were randomly assigned to three different groups:microlaserpeeling mode group (MM group), fractional ablative mode group (FM group) and combined mode group (CM group). MM group received microlaserpeeling mode with depth of 60 μm and a repetition rate of 20%, FM group received fractional ablative mode with depth of 300 μm and a fractional density of 8%, and CM group received a fractional depth of 200 μm, density of 8%, and a peeling depth of 30 μm, repetition rate of 20%. All patients were evaluated for their treatment effects and side effects 30 days after treatment, including the treatment satisfaction, the ECCA grading scale, pain score and pigmentation level.

Results: According to the effect satisfaction of patients' self-assessment, the difference among the three groups was statistically significant (P < .05), the CM group was better than the other two groups, but there was no significant difference between the FM group and the MM group (P > .05). About the ECCA grading scale 30 days after treatment, the statistical result among the three groups was significant (P < .05), the CM group is much lower than the FM group which is approximately equal to the MM group. There was statistical difference in pain score among the three groups and every two groups (P < .05), the CM group had the highest pain score, while FM group had the lowest. About the pigmentation level, there was statistical difference among the three groups (P < .05), FM group had the lightest pigmentation, while the CM group had the heaviest.

Conclusions: Three treatment modes are all effective in treating the concavity acne scar. Among the three modes, CM group is best effective, also accompanied with the most severe side effect; FM group achieves the best balance between treatment effect and side effect. The treatment practices indicate that when the Er:YAG laser with a wavelength of 2940 nm is used to treat concavity acne scars, the right treatment mode should be subject to the severity of the scar.

Copyright © 2021 the Author(s). Published by Wolters Kluwer Health, Inc.