The Clinical and Histological Effect of a Low-Fluence Q-Switched 1,064-nm Neodymium: Yttrium-Aluminum-Garnet Laser for the Treatment of Melasma and Solar Lentigenes in Asians: Prospective, Randomized, and Split-Face Comparative Study.
BACKGROUND
The low-fluence Q-switched 1,064-nm neodymium:yttrium-aluminum-garnet laser (QSNYL) is popular for melasma treatment among Asians.


OBJECTIVE
This study was to evaluate the clinical and histological effects of the low-fluence QSNYL for treatment of melasma and solar lentigenes.


METHODS
In this randomized split-face clinical study, 22 patients with melasma or solar lentigo received low-fluence QSNYL weekly for 10 sessions on one cheek. The treatment efficacy was determined by Mexameter skin colorimetry, physician and patient assessment, and by evaluating histological changes.


RESULTS
The treated sides had statistically significant reductions in the melanin and erythema indices (EI); 50.0% of melasma and 62.5% of solar lentigo patients had >50% clearance after the final treatment. The increased EI, vascularity, and mast cell activity in patients with melasma and large-sized solar lentigo showed no improvement. The recurrence rates were 16.7% and 12.7% for melasma and solar lentigo, respectively. Postinflammatory hyperpigmentation developed in 1 patient, but no serious side effects were noted.


CONCLUSIONS
Low-fluence QSNYL is effective in treating melasma and small type solar lentigo in Asians. The authors' study also demonstrated that lesion thickness, vascularity, and mast cell activity can be used to predict the efficacy of the treatment of these lesions.
Departments of *Dermatology, and †Cosmetic Dermatology and Photomedicine, Wakayama Medical University, Wakayama, Japan.
Chikako
C
Kaminaka
Fukumi
F
Furukawa
Yuki
Y
Yamamoto
D000328:Adult; D044466:Asian People; D002610:Cheek / Q000528:radiation effects; D005260:Female; D006801:Humans; D053844:Lasers, Solid-State / Q000009:adverse effects / Q000627:therapeutic use*; D007911:Lentigo / Q000208:ethnology* / Q000473:pathology / Q000532:radiotherapy*; D028022:Low-Level Light Therapy / Q000009:adverse effects; D008548:Melanosis / Q000208:ethnology* / Q000473:pathology / Q000532:radiotherapy*; D008875:Middle Aged; D011446:Prospective Studies