A Prospective Study in the Treatment of Lentigines in Asian Skin Using 532 nm Picosecond Nd:YAG Laser.

BACKGROUND AND OBJECTIVE: To evaluate safety and efficacy of treatment with the picosecond Nd:YAG 532 nm for lentigines in Asian skin. STUDY DESIGN/MATERIALS AND METHODS: This was a prospective, open-label cohort study, using a novel picosecond 532-nm laser for the treatment of facial lentigines. Subjects received up to three laser treatments every 4-6 weeks and were assessed at 4 and 12 weeks after final treatment. Primary endpoint was degree of improvement in lentigines at 12 weeks after the final treatment, assessed by treating investigator based on Physicians Global Assessment. Secondary end-points included degree of improvement in lentigines at 12 weeks after final treatment, assessed by subject (Subject's Global Assessment), and change in mean relative Melanin index (MI) value at 3 months after final treatment as compared to baseline as assessed by mexameter measurement. RESULTS: A total of 20 patients (3 male, and 17 female) of Asian-descent with Fitzpatrick skin type III and IV, with lentigines on the face were included in this study. A total of 89 lesions were treated with the laser setting of 532-nm, 750 picoseconds, fluence of 0.2-0.5 J/cm 2 , and spot size of 4 mm. One hundred and thirty-seven treatment sessions were given in total. Eighteen patients (90%) achieved a moderate to significant improvement at 12-week follow-up based on a 5-grade physician global assessment scale. The improvement rate of relative MI (MI in the lesion minus normal skin) was 33.30 ± 18.71 and 37.63 ± 19.25% at 4- and 12-week follow-up. Post-inflammatory hyperpigmentation (PIH) occurred in 14 of 137 sessions (10.2%), and hypopigmentation occurred in one patient with five lesions (3.6%). CONCLUSION: This study demonstrates that using picosecond Nd:YAG laser 532 nm for removal of solar lentigines in darker skin type appears to be safe and effective. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc. LIMITATIONS: Small study group.

A retrospective analysis on the management of pigmented lesions using a picosecond 755-nm alexandrite laser in Asians.

BACKGROUND AND OBJECTIVES: Photo-aging in Chinese often presents with benign pigmentary lesions. Q-switched lasers for pigmentary lesions in Asians had reported a risk of post-inflammatory hyperpigmentation (PIH) up to 25%. Longer pulse widths in the millisecond domains were advocated with reduced risk of PIH. Recently, picosecond lasers of various wavelengths were introduced with proven efficacy in tattoo removal. The objective of this study is to assess the efficacy and safety of a novel picosecond 755-nm alexandrite laser for the treatment of benign pigmented lesions in Asians retrospectively. METHODS: A list of all patients who received picosecond 755-nm alexandrite laser treatment at a private dermatology center in Hong Kong was included. Those who had any other laser or topical treatment during the period of picosecond laser treatment were excluded. The age, skin phototype, type of pigmentary lesion, number of treatments performed was recorded. The baseline and most recent standardized photographs were assessed by trained physicians for comparison. A score of 0-4, representing poor 0-24%, fair 25-49%, good 50-74%, excellent 75-95%, and complete 95%+ improvement was given. Adverse events associated with the laser treatment were also recorded. All patients were followed up until 6 months after the last laser session. RESULTS: A total of 13 subjects were included in the present study. The number of treatment sessions received ranged from one to seven. The benign pigmentary lesions consist of Nevus of Ota, café-au-lait patches, lentigines, Becker's nevus, Hori's macules, and nevus spilus. Among patients with Nevus of Ota, one patient achieved complete clearance after four treatments and two other patients had excellent clearance after three and four sessions, respectively. Patients with café-au-lait had fair to good clearance after one to seven treatment sessions. One patient who has Hori's macules was resistant to laser treatments and a fair response was achieved after eight treatments. In the present series, two patients (4.8%) developed transient hypopigmentation, which had improved upon subsequent follow-up in both cases and none had post-inflammatory hyperpigmentation. CONCLUSIONS: The novel picosecond 755-nm alexandrine laser is effective for the treatment of benign pigmentary lesions in Chinese, especially for the clearance of Nevus of Ota. Picosecond laser appears to be associated with a much lower risk of PIH for treatment of pigmentary lesions in Asians.