Study of a 532/1064 Fractional Picosecond Laser for Facial Rejuvenation.

BACKGROUND AND OBJECTIVES: Picosecond (ps) fractional lasers create small wounds, presumably by laser-induced optical breakdown. We studied a ps fractional laser in the treatment of wrinkles and mottled pigment. MATERIALS AND METHODS: This was a single center, prospective, open-label clinical trial. Patients with at least 2 facial areas, with visible wrinkles and dyschromia, were enrolled in the study and received 3 treatments at monthly intervals and appeared at 3 follow-up visits at 1, 3, and 6 months after treatment. The laser is an 800 ps fractional system with nominal 10 mm macrospot diameter. Both 532 nm and 1,064 nm wavelengths were applied in each subject. Wrinkle and pigmentation clearance were assessed by 2 blinded investigators using a 5-point clearance scale. Skin improvement was assessed by investigators using the 5-point Global Aesthetic Improvement (GAI) Scale based on before/after photographs for the following categories: (1) fine lines/wrinkles and (2) pigmentation. RESULTS: A total of 18 healthy subjects at a single site were enrolled. At least moderate pigmentation and fine line/wrinkles improvement were observed in 93% and 79% of patients at 1 month after the last treatment according to GAI, respectively. Pigment clearance approached a mean of approximately 40%. CONCLUSION: A ps 1,064/532 fractional laser achieves reduction in fine lines and pigment.

Melatonin and its metabolites accumulate in the human epidermis in vivo and inhibit proliferation and tyrosinase activity in epidermal melanocytes in vitro.

Melatonin and its metabolites including 6-hydroxymelatonin (6(OH)M), N(1)-acetyl-N(2)-formyl-5-methoxykynuramine (AFMK) and 5-methoxytryptamine (5MT) are endogenously produced in human epidermis. This production depends on race, gender and age. The highest melatonin levels are in African-Americans. In each racial group they are highest in young African-Americans [30-50 years old (yo)], old Caucasians (60-90 yo) and Caucasian females. AFMK levels are the highest in African-Americans, while 6(OH)M and 5MT levels are similar in all groups. Testing of their phenotypic effects in normal human melanocytes show that melatonin and its metabolites (10(-5) M) inhibit tyrosinase activity and cell growth, and inhibit DNA synthesis in a dose dependent manner with 10(-9) M being the lowest effective concentration. In melanoma cells, they inhibited cell growth but had no effect on melanogenesis, except for 5MT which enhanced L-tyrosine induced melanogenesis. In conclusion, melatonin and its metabolites [6(OH)M, AFMK and 5MT] are produced endogenously in human epidermis and can affect melanocyte and melanoma behavior.