Prospective, randomized, evaluator-blinded study of the long pulse 532-nm KTP laser alone or in combination with the long pulse 1064-nm Nd: YAG laser on facial rejuvenation in Asian skin

Abstract

Background and objective: Hyperpigmentation is a common concern in Asian patients. Few published studies address overall skin rejuvenation in this group using long-pulse (LP) laser to target pigmentation and stimulate dermal remodeling. The LP KTP 532-nm laser (LP 532-nm) is used primarily to remove epidermal lesions, while the LP Nd: YAG 1064-nm laser (LP 1064-nm) is used to stimulate dermal remodeling in Asian patients with varying efficacy. The LP 532-nm used alone and in combination with LP 1064-nm to reduce pigmentation and rejuvenate skin was previously evaluated in lighter skin, but not in Asian skin. We evaluated the safety and effectiveness of using LP 532-nm for overall photorejuvenation, with and without LP 1064-nm.

Study design/materials and methods: Four treatments were administered at 3-week intervals to 22 Japanese females with photodamaged facial skin and bilateral solar lentigines. A direct split-face treatment with LP 532-nm was used on the full-face, and an additional, randomized LP 1064 treatment was administered to one-half of the face. Patients were not fully aware which side of the face was treated with which treatment. Results were evaluated at each treatment, and at 1- and 3-month follow-up visits.

Results: Scoring of a modified pigment severity index (mPSI) and measurement of the melanin index (MI) showed that facial skin treated with LP 532-nm alone and in combination with LP 1064-nm resulted in improvement at the 1- and 3-month follow-up (P < 0.001), but there was no difference between the two sides of the face. Notably, the three dimensional analysis of skin surface showed improvements for the dual-wavelength treatments with significant differences between the two sides (P = 0.003). Most patients reported moderate improvement and were extremely satisfied or satisfied with the outcome. Adverse events were minor and rare.

Conclusions: Pigment-related skin rejuvenation using LP 532-nm appears to be safe and effective for Asian skin. The addition of LP 1064-nm showed no clinical difference but the subtle difference was detected by the 3D analyzing device. Lasers Surg. Med. 48:844-851, 2016. © 2016 Wiley Periodicals, Inc.

Keywords: long pulse KTP laser; long pulse Nd: YAG laser; melasma; skin rejuvenation; solar lentigo.