Comparative Effectiveness of 755‐nm Picosecond Laser, 755‐ and 532‐nm Nanosecond Lasers for Treatment of Café‐au‐Lait Macules (CALMs): A Randomized, Split‐Lesion Clinical Trial

Abstract

Background and Objectives Many types of lasers have been used to treat café‐au‐lait macules (CALMs) since the introduction of the selective photothermolysis theory. However, the efficacy and safety of picosecond lasers, compared with those of nanosecond lasers, have not been researched. To compare the efficacy and safety of 755 nm picosecond laser (PS‐755 nm), Q‐switched (QS) Alexandrite 755 nm nanosecond laser (QS‐755 nm), and QS Nd:YAG 532 nm nanosecond laser (QS‐532 nm) for treating CALMs. Study Design/Materials and Methods Forty‐one patients received several treatments at 3‐month intervals. Lesions were divided into two or three approximately equal parts, which were randomly treated with PS‐755 nm, QS‐755 nm, and QS‐532 nm. The safety and efficacy of three lasers were determined based on blinded visual assessments and self‐reports of patients three months after the comparative trial. Results Visual assessment 3 months after the comparative trial revealed that there was no statistically significant difference among the sites treated by QS‐755 nm (2.84 ± 1.11), QS‐532 nm (2.63 ± 1.06), and PS‐755 nm (2.74 ± 1.05) lasers. Five (26.32%) of 19 patients showed lesion recurrence. Adverse effects included acneiform miliaris, hypopigmentation, and hyperpigmentation, which were resolved within 12 months. Five (26.32%) of 19 patients who showed lesion recurrence 1–5 months after laser treatment had lightened or cleared at least 50% of the lesion. 46.67% of patients were satisfied or very satisfied with the outcome of the overall treatment. Conclusions PS‐755 nm, QS‐755 nm, and QS‐532 nm laser treatments were equally effective in treating and improving CALMs. PS‐755 nm caused fewer adverse effects. Individuals can react differently to different types of lasers. Patch tests should be conducted before the treatment. Lasers Surg. Med. © 2020 Wiley Periodicals LLC

Comparison of the safety and efficacy of low fluence Q‐switched 1064‐nm and conventional Q‐Switched 755‐nm lasers in the treatment of café‐au‐lait macules: A prospective self‐controlled trial

“…But 11 lesions treated with LFQS 1064‐nm laser and 7 treated with HFQS 755‐nm laser were included in the Tertile 3 group (3.67 ≤ VAS ≤ 4), suggesting that within 3 months, the LFQS 1064‐nm laser may help more patients achieve the top‐third of efficacy. In our study, five patients (25%) showed significantly different responses to these two types of laser treatments (VAS difference of ≥1 between the efficacy of the two laser treatments), suggesting that the choice of laser type for subsequent treatment should depend on the results of initial test patches, which is consistent with our previous conclusions 3 . There may be two reasons why lesions can be removed by LFQS 1064‐nm laser treatment: irradiation of the target lesion by repetitive laser pulses can lead to cumulative effects that can be tailored to attain complete targeted ablation with minimal damage, 18 and the rate of melanosome regeneration is delayed in cells irradiated with the LFQS 1064‐nm Nd: YAG laser 19 .…”

“…There is no significant difference in the recurrence rate between the two laser treatments. After HFQS 755‐nm laser treatment, 65% of patients ( n = 13) experienced temporary hypigmentation, and the average remission time was 8 weeks (range 2−12 weeks), more than in previous studies (0%−2.44%) 3,22 . Follow‐up visits may not have been frequent enough in previous studies, resulting in a lack of relevant records 3,22 .…”

“…In our study, five patients (25%) showed significantly different responses to these two types of laser treatments (VAS difference of ≥1 between the efficacy of the two laser treatments), suggesting that the choice of laser type for subsequent treatment should depend on the results of initial test patches, which is consistent with our previous conclusions. 3 There may be two reasons why lesions can be removed by LFQS 1064-nm laser treatment: irradiation of the target lesion by repetitive laser pulses can lead to cumulative effects that can be tailored to attain complete targeted ablation with minimal damage, 18 and the rate of melanosome regeneration is delayed in cells irradiated with the LFQS 1064-nm Nd: YAG laser. 19 The lesion can be removed by HFQS 755-nm laser treatment may be because the melanin particles are released into the extracellular medium, removed through the lymphatic system, and then absorbed by macrophages.…”

“…Our previous prospective self-controlled study showed that picosecond 755-nm, QS 755-nm, and QS 532-nm laser treatments were equally effective in treating CALMs. 3 In recent years, many studies have reported that the low fluence QS 1064-nm neodymium-doped yttrium aluminum garnet (Nd: YAG) laser can treat facial rejuvenation, nevus of Ota, melasma, acquired dermal melanoses, and other diseases. [4][5][6] Patients show good treatment tolerance without bleeding or scab formation and the erythema naturally subsides within a few hours after treatment.…”

Q-Switched 1064/532 nm Laser with Picosecond Pulse to Treat Benign Hyperpigmentations: A Single-Center Retrospective Study

“…Melanosis' elimination for cosmetic reasons is a common request in aesthetic dermatology [1][2][3][4]. Hyperpigmentations can be described as the darkening of the skin secondary to melanin increasing in skin layers.…”