The Comparison of the Efficacy and Safety of Fractional 1064 nm Nd:YAG Picosecond Laser and Fractional Q-Switched 1064-nm Nd:YAG Laser in the Improvement of Photoaging: A Split-Face Study.

backgroundFacial photoaging is a complex biological process influenced by both internal and external factors. It is characterized by wrinkles, enlarged pores, and rough skin. Despite various clinical treatments, they often have limited effectiveness, significant side effects, and extended recovery times. There is a need for more effective and safer treatment options. Preliminary evidence suggests significant differences in mechanisms between fractional 1064 nm Nd:YAG picosecond laser (FxPico) and fractional Q-switched 1064-nm Nd:YAG laser (QSF-Nd:YAG). Photothermal tissue modulation is achieved in the QSF-Nd:YAG platform through holographic beam splitting, whereas the FxPico system's microlens arrays (MLA) enable dual-mode action through concurrent photothermal and laser-induced optical breakdown (LIOB) mechanisms. The purpose of this study was to conduct a split-face controlled trial on the same subject, observing the therapeutic effects of both modalities.

methodsThirty patients with photoaging underwent five treatment sessions at weeks 0, 2, 4, 6, and 8. Each patient received FxPico on one side of the face and QSF-Nd:YAG on the other. Follow-up evaluations were conducted at 1 and 3 months post-treatment. Efficacy was assessed using VISIA quantitative analysis, reflectance confocal microscopy (RCM), and histological examination. Safety was evaluated based on adverse events and patient-reported pain.

resultsAmong the patients following the completion of five treatment sessions exhibited remarkable improvement in terms of facial wrinkles, pores and skin texture from VISIA quantitative numerical assessment (p < 0.001). Semi-quantitative assessments from reflectance confocal microscopy analysis also demonstrated a significant decrease (p < 0.05). There were no statistically significant differences observed in the reduction rates of wrinkles, pores, skin texture counts, semi-quantitative scores, and the Global Aesthetic Improvement Scale scores (p > 0.05) between the FxPico and QSF-Nd:YAG sides. Histological analysis revealed increased collagen formation and improved elastic fiber alignment in both treatment groups, which objectively validates the therapeutic efficacy of both laser modalities for photoaging. Adverse events were mild, with FxPico causing more pain (p < 0.0001).

conclusionBoth FxPico and QSF-Nd:YAG lasers are effective and safe for improving photoaging, with no significant differences in clinical outcomes. FxPico may offer superior collagen stimulation, albeit with higher pain levels.

trial registrationChina Clinical Trial Registry: ChiCTR2200058566.