The purpose of this study was to evaluate the efficacy and safety of pulsed-dye laser (PDL) and near-infrared light (NAFL) in treating surgical scars. Healing via time alone has not been compared to PDL or NAFL. Therefore, an urban academic medical center conducted a randomized, controlled, single-blind clinical trial. Adults in good health who had had primary closure of an incision in the skin were randomly assigned to receive either 3 sessions of combination PDL and NAFL every 2-8 weeks or no therapy at all. Both the Patient and Observer Scar Assessment Scale and the Scar Cosmesis Assessment and Rating were performed by both participants and blinded physicians at both the baseline and 36-week follow-up visits. 

In this study, scar improvement was the primary endpoint, and the mean change in scores over time was used as an indicator of success. About 52 people out of 76 finished the study (July 2017 to June 2019). There were no serious side effects noted. However, patient reports [mean difference (standard deviation), laser: 12.86 (6.91) vs. control: 7.25 (6.34); P = 0.004] and observer reports [18.32 (8.69) vs 13.08 (9.63); P = 0.044)] on the Scar Assessment Scale revealed an improvement in overall score in the laser group compared to controls. 

When comparing the effects of lasers and conventional treatments, patients noted greater reductions in scar thickness (3.68 (2.04) vs. 1.88 (1.85); P = 0.002) and stiffness (3.57 (2.78) vs. 1.50 (2.11); P = 0.004), while doctors noted greater reductions in vascularity (3.71 (1.98) vs. 1.71 (1.52); P = 0.0002). Lasers led to a statistically significant increase in the subscore for erythema on the live Scar Cosmesis Assessment and Rating [1.04 (0.79) vs. 0.42 (0.50); P = 0.001]. Improvement of the scarring was seen after PDL and NAFL were used together. Scars became less thick, less rigid, and less red.