Background: Fractionated photothermolysis (FP) is used for the treatment of facial wrinkles.
Objectives: Investigation of effects of different FP treatment parameters in the treatment of facial wrinkles.
Patients and methods: In a randomized split-face controlled study 11 patients received 3 FP sessions in 4-week intervals. Keeping the total energy input for each facial side constant, one side was treated with 6 mJ/MTZ with relatively high MTZ density (up to 2,625 MTZ/cm2) and the contralateral side with 70 mJ/MTZ with lower MTZ density (up to 230 MTZ/cm2). Follow-up (FU) visits were performed 1, 3, and 6 months after the last treatment. The cosmetic evaluation was done by the patient self-assessments and by assessment of standardized photographs by 3 independent, blinded investigators. Post-treatment side effects were documented daily in a patient diary up to 7 days after the procedure.
Results: After 6 months, the patient self-assessments indicated significant improvements (p < 0.005) in wrinkle severity from 5.2 ± 1.5 to 3.8 ± 1.3 and 3.7 ± 1.3 for 6 and 70 mJ/MTZ, respectively, but without significant difference between the energy levels. In contrast, the photographic evaluation by the blinded investigators showed that wrinkle severity was rated significantly better at the sites treated with 70 mJ/MTZ than at the sites treated with 6 mJ/MTZ (p < 0.01). Treatment with 70 mJ/MTZ was significantly more painful than treatment with 6 mJ/MTZ. The typical local reactions to FP, erythema and edema, were also significantly more intense after 70 mJ/MTZ and lasted longer.
Conclusions: FP with higher energy per MTZ at constant total energy input is more effective in the treatment of facial wrinkles than lower energy. The gain in effectiveness is, nonetheless, accompanied by an increase in adverse reactions. The treating physician may use this information to adjust treatment to the preferences of the individual patient.