The Efficacy Of A Dual-wavelength Laser System(585nm And 1,064nm) In The Treatment Of Keloid: A Self-control Study

ObjectiveTo investigate the efficacy and safety of a dual-wavelength laser system in the treatment of keloid.MethodsThirty-four patients with thirty-eight paired keloids which had received no previous treatment were enrolled. All of the keloids tended to be red in color. One keliod of each pair was randomly treated by a dual-wavelength laser system for 4 sessions at an interval of 4-6 weeks. The other one in the same anatomic site received no treatment and served as a control lesion. PDL irradiation was done using a fluence of 4.5-6.0 J/cm2, a pulse duration of 0.5 ms, and a 7-mm spot size handpiece. After a delay of 50-100 ms, the PDL was followed by the Nd:YAG laser at 45-60 J/cm2 fluence with 15 ms duration. Skin erythema index (EI) and melanin index (MI) of the keloids were measured before each session and at every follow-up visit using a Mexameter. Three-dimensional (3D) microtopography imaging system was used to evaluate the material volume (MV). Reflectance Confocal-Laser-Scanning Microscopy (CLSM) in vivo assessments of laser-induced dynamic alterations of cutaneous microcirculation was performed before and 4 weeks after each session. The mean value of capillary diameters (MVCD) was caculated using the software Image-Pro Plus 6.0. The score of pliability was evaluated by one blinded dermatologist and the patient themselves using the Patient and Observer Scar Assessment Scale (POSAS). The average was calculated. Meanwhile the score of itching and pain of each keloid was assessed by patients themselves using POSAS.ResultsThe El, MV, MVCD of the treatment group decreased from the baseline at a percentage of 13.29%(P<0.05),23.93%(P<0.05),55.05%(P<0.05) respectively. The MI of the treatment group increased by 10.58%(P>0.05). No statistical difference was found in the control group. The score of pliability, itching and pain of the treatment group significantly decreased from the baseline at a percentage of 31.16%(P<0.05) 58.91%(P<0.05),59.03%(P<0.05) respectively. The main side effects included pain or mild discomfort in the process of treatement, transient purpura and mild swelling of the lesion shortly after each treatment, et al. All of the above side effects relieved in 7 days. Only one lesion had vesicals and transient hyperpigmentation but recovered in 3 months. There was no hypopigmentation and new scar formation.ConclusionsThe dual-wavelength laser could effectively improve the erythema and the size of keloid, reduce the blood flow of superficial derma and relieve itching and pain in patients. It had few side effects and was safe and easy to be accepted by the patients. Long-term effects remain to be followed up.