Which type of atrophic acne scar (ice-pick, boxcar, or rolling) responds to nonablative fractional laser therapy?

Background: Few studies have examined the role of fractional lasers in individual acne scars (ice-pick, box car, rolling) using objective assessment tools in darkly pigmented skin.

Objective: To evaluate the effect of 1,540-nm fractional lasers on individual acne scars.

Methods: A prospective interventional study was conducted in 35 patients using a 1,540-nm fractional laser. Six sessions were performed with four passes per session and a dose varying from 70 to 100 mJ to maximize the DWR. A self-devised objective assessment tool with dose settings to optimize the depth-to-width ratio (DWR) and a visual analog scale (VAS) were used to count individual atrophic scars. Final results were assessed 6 months after final laser treatment.

Results: Acne scar reduction efficiency was used to validate the improvement of individual scars, a meaningful difference was considered as 51% or greater improvement. The boxcar scars (52.9%) responded better than the rolling (43.1%) and ice-pick scars (25.9%), with statistically significant improvement (p < .05) seen in boxcar scars after four sessions. Overall VAS scores revealed significant improvement (p < .001).

Conclusions: Using an objective evaluation tool, an erbium-doped glass laser was found to improve atrophic acne scars, markedly so for boxcar and rolling scars. The VAS score overestimated improvement because of its subjective nature.