Ultrastructure: effects of melanin pigment on target specificity using a pulsed dye laser (577 nm)

Journal Article · Mon Jun 01 00:00:00 EDT 1987 · J. Invest. Dermatol.; (United States)

DOI:https://doi.org/10.1111/1523-1747.ep12470418· OSTI ID:6329634

Tong, A K; Tan, O T; Boll, J; Parrish, J A; Murphy, G F

It has been shown recently that brief pulses of 577 nm radiation from the tunable dye laser are absorbed selectively by oxyhemoglobin. This absorption is associated with highly specific damage to superficial vascular plexus blood vessels in those with lightly pigmented (type I-II) skin. To determine whether pigmentary differences in the overlying epidermis influence this target specificity, we exposed both type I (fair) and type V (dark) normal human skin to varying radiant exposure doses over 1.5-microsecond pulse durations from the tunable dye laser at a wavelength of 577 nm. Using ultrastructural techniques, we found in type I skin that even clinical subthreshold laser exposures caused reproducible alterations of erythrocytes and adjacent dermal vascular endothelium without comparable damage to the overlying epidermis. In contrast, degenerated epidermal basal cells represented the predominant form of cellular damage after laser exposure of type V skin at comparable doses. We conclude that epidermal melanin and vascular hemoglobin are competing sites for 577 nm laser absorption and damage, and that the target specificity of the 577 nm tunable dye laser is therefore influenced by variations in epidermal pigmentation. This finding is relevant to the clinical application of the tunable dye laser in the ablative treatment of vascular lesions. We also found on ultrastructure that the presence of electron-lucent circular structures of approximately 800 A in diameter were observed only at and above clinical threshold doses in those with type I skin and at the highest dose of 2.75 J/cm2 in type V skin. It has been proposed that these structures might be heat-fixed molds of water vapor. Both this and ultrastructural changes of epidermal basal cells demonstrate mechanisms responsible for alteration of tissue after exposure to 577 nm, which are discussed.

• Research Organization: Boston Univ. School of Medicine, MA
• OSTI ID: 6329634
• Journal Information: J. Invest. Dermatol.; (United States), Vol. 6
• Country of Publication: United States
• Language: English

Related Subjects

29 ENERGY PLANNING
POLICY AND ECONOMY
LASER RADIATION
BIOLOGICAL EFFECTS
SKIN
ULTRASTRUCTURAL CHANGES
BLOOD VESSELS
DYE LASERS
EPIDERMIS
ERYTHROCYTES
HEMOGLOBIN
MELANIN
PURPURA
ANIMAL TISSUES
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BODY
BODY FLUIDS
CARBOXYLIC ACIDS
CARDIOVASCULAR SYSTEM
DISEASES
ELECTROMAGNETIC RADIATION
EPITHELIUM
GLOBIN
HEMIC DISEASES
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
HYDROXY COMPOUNDS
LASERS
LIQUID LASERS
MATERIALS
MORPHOLOGICAL CHANGES
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
PIGMENTS
PORPHYRINS
PROTEINS
RADIATIONS
TISSUES
290400* - Energy Planning & Policy- Energy Resources