Histology of ex vivo skin after treatment with fractionated picosecond Nd:YAG laser in high and low-energy settings

Biopsy samples from East Asian subjects were treated with either a Resolve 532-nm handpiece or a Resolve 1064-nm handpiece and examined for laser-induced optical breakdowns and intradermal laser-induced cavitations. Superficial, intra-epidermal LIOBs were seen in skin treated with higher laser energies. Deep, intradermal LICs were seen in skin treated at lower energies.

PubMed Reference: Yeh YT, Peng JH, Peng P. J Cosmet Laser Ther. 2020 Jan 3:1-5.

Study Details: 

• 6 skin samples were taken from clinically normal-looking perilesional areas of East-Asian subjects: 1 biopsy sample was from a female arm (age 36 years, Fitzpatrick skin type III) and 5 samples were from a male thigh (age 46 years, Fitzpatrick skin type IV)
• After biopsy, 3 skin samples were treated with Resolve 532-nm handpiece (pulse duration 375 ps; fluence of 0.3 or 0.2 mJ/microbeam) and 3 samples with Resolve 1064-nm handpiece (pulse duration 450 ps; fluence of 1.9 or 2.3 mJ/microbeam)
• Samples were examined by a dermatopathologist for intra-epidermal, laser-induced optical breakdowns (LIOBs) and intra-dermal, laser-induced cavitations (LICs)

Study Results: 

• Superficial, intra-epidermal LIOBs were seen in skin treated with higher laser energies.
• Deep, intradermal LICs were seen in skin treated at lower energies
• Lesions were spaced in 600-μm intervals or its multiple
• Lesion sizes and depths were consistent with previously reported values on Caucasian skin