Nouri Keyvan, Chen Halland, Saghari Sogol, Ricotti Carlos A
Department of Dermatology and Cutaneous Surgery, University of Miami School of Medicine, 1475 NW 12th Avenue, Suite 2175, Miami, FL 33136, USA.
Dermatol Surg. 2004 Apr;30(4 Pt 1):494-7. doi: 10.1111/j.1524-4725.2004.30162.x.
Laser epilation is based on the principle of selective photothermolysis, absorption of laser energy by the target chromophore melanin. It is claimed that larger spot sizes may be more effective for hair removal at identical fluences.
To compare the efficacy of 18- vs. 12-mm spot size in hair removal using a Gentlelase Alexandrite laser from Candela Corporation (Boston, MA).
In this double-blind, randomized control trial, patients underwent laser-assisted hair removal on the axillary region. Regions were randomly selected and treated with either an 18- or a 12-mm spot size. Three treatments at 6-week intervals with a 755-nm Gentlelase Alexandrite laser (Candela Corp., Canton, MA) at a fluence of 16 J/cm(2) with cooling and delay times of 60 ms. Hair counts were taken before each treatment session and compared. The mean percentage hair reduction and student's paired t-test were used to compare 18 versus 12 mm versus control sites at each visit and compared it with the baseline hair count.
There was a 10.3% difference in mean reduction favoring the 18-mm spot size treated area at the 6-month follow-up.
Our results indicate that a larger spot size appears to be more effective for laser assisted hair removal.
激光脱毛基于选择性光热解原理，即目标发色团黑色素吸收激光能量。据称，在相同能量密度下，较大光斑尺寸可能对脱毛更有效。
比较使用Candela公司（马萨诸塞州波士顿）的Gentlelase翠绿宝石激光，18毫米光斑尺寸与12毫米光斑尺寸在脱毛方面的疗效。
在这项双盲随机对照试验中，患者接受腋窝区域的激光辅助脱毛。随机选择区域，分别用18毫米或12毫米光斑尺寸进行治疗。使用波长755纳米的Gentlelase翠绿宝石激光（Candela公司，马萨诸塞州坎顿），能量密度为16 J/cm²，冷却和延迟时间为60毫秒，每隔6周进行三次治疗。在每次治疗前进行毛发计数并比较。使用平均毛发减少百分比和学生配对t检验，在每次就诊时比较18毫米与12毫米治疗区域以及对照区域，并与基线毛发计数进行比较。
在6个月的随访中，平均减少率上，18毫米光斑尺寸治疗区域比其他区域高10.3%。
我们的结果表明，较大光斑尺寸在激光辅助脱毛中似乎更有效。
