Nonablative fractional laser (NAFL) therapy is a noninvasive procedure that has been suggested as a treatment option for hypertrophic scars.


To evaluate the efficacy and safety of 1540-nm NAFL therapy in the treatment of hypertrophic scars.

Materials and Methods

An intraindividual randomized controlled trial (RCT) with split lesion design and single-blinded outcome evaluations. Patients received four NAFL treatments at monthly intervals. Primary endpoint was a blinded on-site visual and palpable Physician Global Assessment (PhGA). Adverse event registration and pain evaluation were used to evaluate safety. Patient global assessment (PGA) was a secondary endpoint to additionally evaluate efficacy.


The PhGA did not find a statistically significant difference between the treated and untreated control side of 18 patients, although there was significant difference on the PGA 1 (= .006) and 3 (= .02) months after last treatment (Wilcoxon signed rank test). Patients experienced moderate pain during treatment and mild adverse events.


In this trial, blinded PhGA could not confirm the clinical efficacy of 1540-nm nonablative fractional laser in the treatment of hypertrophic scars, but the treatment is safe, and patients judged that the treated part had a better global appearance.