Selective photothermolysis of cutaneous pigmentation by Q-switched Nd: YAG laser pulses at 1064, 532, and 355 nm

Journal Article · Sat Jul 01 04:00:00 EDT 1989 · J. Invest. Dermatol.; (United States)

DOI:https://doi.org/10.1111/1523-1747.ep12277339· OSTI ID:5814615

Anderson, R R; Margolis, R J; Watenabe, S; Flotte, T; Hruza, G J; Dover, J S

Exposure of skin to nanosecond-domain laser pulses affects the pigmentary system by a process called selective photothermolysis, in which melanosomes and pigmented cells are preferentially altered. Due to the broad absorption spectrum of melanin, this effect may occur with wavelengths that penetrate to vastly different depths within tissue, potentially producing different biologic responses. The effects of single near-ultraviolet (355 nm), visible (532 nm), and near infrared (1064 nm) pulses of 10-12 nsec duration were determined in guinea pig skin using gross, histologic, and electron microscopic observations. Threshold response in pigmented skin was a transient immediate ash-white discoloration, requiring 0.11, 0.20, and 1.0 J/cm2, at 355, 532, and 1064 nm, respectively. At each wavelength, melanosomes were ruptured within keratinocytes and melanocytes, with cytoplasmic and nuclear alterations. Delayed epidermal depigmentation occurred, followed by gradual repigmentation. Deep follicular cells were altered only at 532 and 1064 nm, which produced permanent leukotrichia. The action spectrum for threshold response was consistent with mechanisms implied by selective photothermolysis. These data may be useful for consideration of treatment for cutaneous pigmentation abnormalities or unwanted follicular pigmentation, or both.

• Research Organization: Massachusetts General Hospital, Boston (USA)
• OSTI ID: 5814615
• Journal Information: J. Invest. Dermatol.; (United States), Journal Name: J. Invest. Dermatol.; (United States) Vol. 93:1; ISSN JIDEA
• Country of Publication: United States
• Language: English

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560400* -- Other Environmental Pollutant Effects
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMALS
BIOLOGICAL EFFECTS
BODY
ELECTROMAGNETIC RADIATION
ELECTRON MICROSCOPY
GUINEA PIGS
LASER RADIATION
LASERS
MAMMALS
MICROSCOPY
NEODYMIUM LASERS
ORGANS
RADIATIONS
RODENTS
SENSITIVITY
SKIN
SOLID STATE LASERS
VERTEBRATES