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

Abstract

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 Prospective Randomized Controlled Study of Oral Tranexamic Acid for the Prevention of Postinflammatory Hyperpigmentation After Q‐Switched 532‐nm Nd:YAG Laser for Solar Lentigines

“…This finding may indicate the efficacy of TA in enhancing PIH clearance, since the maximum onset of PIH had already occurred at the 4th week. However, novel lasers or energy‐based devices have been used to treat SLs ; oral TA might possibly have different results with regard to PIH after the treatment with these devices. Further studies are required to elucidate this.…”

A Systematic Review of Picosecond Laser in Dermatology: Evidence and Recommendations

“…Guss et al used a 375 picoseconds pulsed 532 nm frequency-doubled Nd:YAG laser to treat 255 discrete lentigines in six patients with type IV skin [26]. A later study by Chan et al confirmed these data, but with a reported PIH rate of 10.2% [27]. The PIH rate between 5 and 10% as reported in the latter two studies is consistent with the authors' clinical experience, whereas the low rate of 1% seen by Guss et al may have been an underestimation due to the retrospective nature of their study, differences in methodology used to calculate PIH rate, and low sample size.…”

“…Picosecond lasers with wavelengths of 532, 755, and 1064 nm have been reported to be safe and effective in the treatment of a wide range of discrete pigmented lesions including solar lentigines, freckles, verrucus epidermal nevus, café au lait macules (CALM), nevus of Ota, and Hori's macules. A total of five case reports/series; five retrospective reviews; three prospective open-label trials; and four split-face/lesion randomized comparison trials involving a cumulative 320 subjects have documented these findings [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29].…”

Use of a Picosecond Alexandrite Laser for Treating Acquired Bilateral Nevus of Ota‐Like Macules in Chinese Patients

“…Picosecond laser has been successfully used to remove not only tattoos which include both skin and mucous membranes, but also benign pigmentation disorders. And it's well effective and safe [13][14][15][16]. Wong et al [17] reported the successful application of a picosecond laser (532 nm/1064 nm, 750 picoseconds) with a fractionating microlens array for treating three patients with ABNOMs in 2018.…”