Ross Edward V, Domankevitz Yacov
Scripps Clinic, San Diego, California.
Candela Corporation, Wayland, California.
Lasers Surg Med. 2021 Oct;53(8):1020-1025. doi: 10.1002/lsm.23381. Epub 2021 Jan 28.
The 1064 nm wavelength is optimized for dark skin, but within the range of available fluences for commercially available 1064 nm devices, may not provide effective treatment for lighter hair. The 755 nm alexandrite wavelength can treat a full range of hair colors but is not ideal for darker skin. The hypothesis is that a new laser system capable of emitting 755/1064 nm wavelengths simultaneously allows for safer, effective, and less painful hair reduction over a range of skin and hair types.
STUDY DESIGN/MATERIALS AND METHODS: We completed treatment in 36 patients in this institutional review board approved prospective randomized study. Ages ranged from 20 to 55 and the distribution of skin types was: I (14% of patients), II (50% of patients), III (18% of patients), IV (18% of patients). Areas included the axilla and lower extremity. A prototype laser system emitted 755/1064 nm simultaneously. The spot size was 12 mm and the pulse duration was 3 milliseconds. The percentage of each wavelength in the mixture varied from 0% to 100%. Total radiant exposure ranged from 20 to 50 J/cm . Test spots were performed with escalating doses of light for each category (alexandrite alone, Nd YAG alone, and blended). Patients returned within 1 week for evaluation of side effects. The highest fluence without side effects for each category was then applied in two sessions 1 month apart. Final hair counts were performed 2 months after the final treatment.
Optimal light doses (in J/cm ) for the range of skin types were as follows: for alexandrite alone, YAG alone, and blended. (Skin type I) 40, 70, 40-10; (II) 40, 70, 40-10; (III) 34, 60, 30-20; (IV) 26, 60, 20-30; (V) 18, 50, 14-36. After 2 months, there was greater than 50% hair reduction in 40%, 24%, and 60% of subjects on the lower extremity for the alexandrite, Nd YAG, and blended groups, respectively, and 20%, 25%, and 24% for the axilla. Our data show that for "challenging" cases, that is, darker skin types or tanned skin with lighter hairs, a 70/30 mixture of Nd:YAG and alexandrite wavelengths tended to produce the greatest hair reduction and least epidermal compromise while maintaining a lower pain level than Nd YAG alone.
Modeling and data suggest that 755/1064 nm mixture is useful in lighter hair removal treatment for darker skin types. Lasers Surg. Med. © 2021 Wiley Periodicals LLC.
1064纳米波长针对深色皮肤进行了优化，但在市售1064纳米设备可用能量密度范围内，可能无法有效治疗浅色毛发。755纳米翠绿宝石波长可治疗所有发色，但对深色皮肤并不理想。假设是一种能够同时发射755/1064纳米波长的新型激光系统，在一系列皮肤和毛发类型上可实现更安全、有效且疼痛较轻的脱毛效果。
研究设计/材料与方法：在这项经机构审查委员会批准的前瞻性随机研究中，我们对36名患者完成了治疗。年龄范围为20至55岁，皮肤类型分布为：I型（14%的患者）、II型（50%的患者）、III型（18%的患者）、IV型（18%的患者）。治疗部位包括腋窝和下肢。一台原型激光系统同时发射755/1064纳米波长。光斑大小为12毫米，脉冲持续时间为3毫秒。混合物中每种波长的百分比从0%到100%不等。总辐射暴露范围为20至50焦/平方厘米。对每个类别（单独使用翠绿宝石、单独使用钕钇铝石榴石以及混合使用）用递增剂量的光进行测试光斑。患者在1周内返回评估副作用。然后将每个类别无副作用的最高能量密度分两次、间隔1个月应用。在最后一次治疗后2个月进行最终毛发计数。
不同皮肤类型的最佳光剂量（单位为焦/平方厘米）如下：单独使用翠绿宝石、单独使用钕钇铝石榴石以及混合使用。（I型皮肤）40、70、40 - （此处原文有误，推测应为40 - 10）；（II型）40、70、40 - 10；（III型）34、60、30 - 20；（IV型）26、60、20 - 30；（V型）18、50、14 - 36。2个月后，下肢接受翠绿宝石、钕钇铝石榴石和混合组治疗的受试者中，分别有40%、24%和60%的毛发减少超过50%，腋窝部位分别为20%、25%和24%。我们的数据表明，对于“具有挑战性”的病例，即深色皮肤类型或浅色毛发的晒黑皮肤，钕：钇铝石榴石和翠绿宝石波长70/30的混合物在减少毛发方面效果最佳，对表皮的损伤最小，同时保持比单独使用钕钇铝石榴石更低的疼痛程度。
模型和数据表明，755/1064纳米混合物在针对深色皮肤类型的浅色毛发去除治疗中是有用的。《激光外科与医学》。©2021威利期刊有限责任公司。
