The Nd:YAG Laser

This laser emits light at a wavelength of 1064 nm, and skin penetration of this laser will be the highest of the lasers discussed while the melanin absorption will be the lowest [97]. This low melanin absorption has been used to design lasers that are safer for the skin of subjects with darker skin, or tanned skin [64]. In a study comparing the efficacy and com­plications of the long-pulsed Nd:YAG Laser and the diode laser, and undertaken in Chinese subjects, Chan and his colleagues found that the long-pulsed Nd:YAG was associated with more pain [98]. They report hypopigmentation as the only long-lasting side effect in their treatment of the underarm and legs that was resolved by 36 weeks. In a study of 11 subjects with Types IV-VI, comparing an IPL system to the Nd:YAG, Goh found that the hair reduction was similar between the two systems [83]. Pain was higher in the Nd:YAG; how­ever, no side effects were seen with the Nd:YAG. Three patients experienced blistering, followed by postinflammatory pigmentation with the IPL system [83]. Galadari compared the alexandrite, Nd:YAG, and the Diode laser in a group of subjects with skin types IV-VI [99]. He reports that the amount of hair reduction did not differ between the three lasers; however the Nd:YAG gave fewer side effects than the other two lasers. Alster et al. treated 20 subjects with skin types IV-VI with dark hair. The authors report significant hair reduc­tion one year after the last treatment (70-90%). The adverse effects in this study included mild to moderate treatment of pain and rare occurrences of transient changes in skin pigment. Histological examination found no epidermal damage tissue with this laser treatment [100]. The Nd:YAG laser has also been used to treat pseudofolliculitis barbae. Both Ross and Weaver report improvement in this condition without long-lasting side effects. [101,102]. Lanigan, in a study of subjects with skin types IV-VI, found that side effects associated with treatment increased with skin type. In this study, there were side effects in 2% of those with type IV, and 20% for types V and VI (Table 8.4) [65].