目的:黑素体破坏的阈值注量有可能为使用皮秒激光建立色素性病变治疗的临床终点提供可靠的数值指标。尽管以前报道了755nm皮秒激光的阈值,波长依赖性尚未被研究。在这项研究中,确定了黑素体破坏的波长依赖性阈值通量。使用基于阈值的数学模型,辐照参数为532-,730-,755-,785-,和1064nm皮秒激光治疗进行了定量评估。
方法:使用不同通量的皮秒激光照射从猪眼睛中提取的黑色素体悬浮液。通过动态光散射测量被照射的黑色素体的平均粒径,通过扫描电子显微镜观察它们的破坏,以确定破坏阈值。建立了数学模型,结合获得的阈值和MonteCarlo光传输来计算破坏皮肤组织内黑色素体所需的照射参数。
结果:对于532-,阈值注量确定为0.95、2.25、2.75和6.50J/cm²,730-,785-,和1064-nm皮秒激光器,分别。数值结果定量地揭示了辐照波长之间的关系,事件通量,以及破坏分布在皮肤组织不同深度的黑色素体所需的斑点大小。计算出的照射参数与临床参数一致,临床参数显示出高疗效,并发症发生率低。
结论:确定了黑素小体破坏的波长依赖性阈值。基于阈值的分析对辐照参数的评估结果提供了数值指标,用于设置532-,730-,755-,785-,和1064-nm皮秒激光器。
A threshold fluence for melanosome disruption has the potential to provide a robust numerical indicator for establishing clinical endpoints for pigmented lesion treatment using a picosecond laser. Although the thresholds for a 755-nm picosecond laser were previously reported, the wavelength dependence has not been investigated. In this study, wavelength-dependent threshold fluences for melanosome disruption were determined. Using a mathematical model based on the thresholds, irradiation parameters for 532-, 730-, 755-, 785-, and 1064-nm picosecond laser treatments were evaluated quantitatively.
A suspension of melanosomes extracted from porcine eyes was irradiated using picosecond lasers with varying fluence. The mean particle size of the irradiated melanosomes was measured by dynamic light scattering, and their disruption was observed by scanning electron microscopy to determine the disruption thresholds. A mathematical model was developed, combined with the threshold obtained and Monte Carlo light transport to calculate irradiation parameters required to disrupt melanosomes within the skin tissue.
The threshold fluences were determined to be 0.95, 2.25, 2.75, and 6.50 J/cm² for 532-, 730-, 785-, and 1064-nm picosecond lasers, respectively. The numerical results quantitatively revealed the relationship between irradiation wavelength, incident fluence, and spot size required to disrupt melanosomes distributed at different depths in the skin tissue. The calculated irradiation parameters were consistent with clinical parameters that showed high efficacy with a low incidence of complications.
The wavelength-dependent thresholds for melanosome disruption were determined. The results of the evaluation of irradiation parameters from the threshold-based analysis provided numerical indicators for setting the clinical endpoints for 532-, 730-, 755-, 785-, and 1064-nm picosecond lasers.