Lewis Kevan G, Nahm Walter K, Schmidt Adriana N, Moy Ronald L
Division of Dermatology, University of California-Los Angeles, CA 90024, USA.
J Am Acad Dermatol. 2004 Feb;50(2):247-52. doi: 10.1016/j.jaad.2003.07.008.
Hypopigmentation is an adverse outcome associated with carbon-dioxide (CO(2)) laser resurfacing. A 90-microsecond pulse produces a more favorable postoperative course of healing, erythema, and pain compared with a 900-microsecond dwell time. The rate of hypopigmentation after 90-microsecond pulsed CO(2) resurfacing may also be reduced. To date, there have been no comprehensive reports on the effect of varying pulse duration on the occurrence of hypopigmentation.
We sought to investigate the relationship between pulse duration and the occurrence of hypopigmentation after CO(2) laser resurfacing.
We conducted a retrospective review of 447 consecutive patients who were treated with a 90-microsecond pulsed CO(2) laser (n = 229) or a continuous wave CO(2) laser with a modifiable dwell time (100-950 microseconds, n = 218). Follow-up ranged from 8 to 61 months (median: 27).
A series of 4 threshold dwell times (range: 90-950 microseconds) were used to divide patients into 2 treatment groups (above and below) at each threshold. The rates of hypopigmentation between groups were similar (range: 6.37%-9.09%) and serial chi-square testing revealed no statistical differences between groups for each dwell time tested (P < 1.0).
No significant relationship between pulse duration and the occurrence of hypopigmentation was observed.
色素减退是二氧化碳（CO₂）激光换肤术的一种不良后果。与900微秒的驻留时间相比，90微秒的脉冲产生的术后愈合过程、红斑和疼痛情况更有利。90微秒脉冲CO₂换肤术后色素减退的发生率也可能降低。迄今为止，尚无关于不同脉冲持续时间对色素减退发生影响的综合报告。
我们试图研究脉冲持续时间与CO₂激光换肤术后色素减退发生之间的关系。
我们对447例连续患者进行了回顾性研究，这些患者接受了90微秒脉冲CO₂激光治疗（n = 229）或驻留时间可调节的连续波CO₂激光治疗（100 - 950微秒，n = 218）。随访时间为8至61个月（中位数：27个月）。
使用一系列4个阈值驻留时间（范围：90 - 950微秒）在每个阈值将患者分为2个治疗组（高于和低于阈值）。组间色素减退率相似（范围：6.37% - 9.09%），连续卡方检验显示在测试的每个驻留时间组间无统计学差异（P < 1.0）。
未观察到脉冲持续时间与色素减退发生之间存在显著关系。
