title: Effects of intense pulsed light and the 1,064 nm Nd:YAG laser on sun-damaged human skin: histologic and immunohistochemical analysis.
abstract: BACKGROUND
  Nonablative methods may produce collagen synthesis in sun-damaged skin.
  
  
  OBJECTIVE
  To study the effects of intense pulsed light (IPL) and 1,064 nm neodymium:yttrium-aluminum-garnet (Nd:YAG) laser: a histologic and immunohistochemical analysis of sun-damaged skin.
  
  
  METHODS
  Nine subjects participated. Five subjects received five-monthly treatments with IPL (560 nm cutoff filter, 8 x 35 mm spot size, pulse duration 2.4/4.2 milliseconds, pulse delay 15 milliseconds, fluence 28-35 J/cm2). Four subjects received treatment with a 1,064 nm Nd:YAG laser (130 J/cm2, triple pulse, 7.0/7.0/7.0-millisecond pulse duration, 75-millisecond delay). Routine histology and immunohistochemistry on 2 mm punch biopsies were taken before treatment and then at 3 and 6 months. We quantified collagen in the upper dermis and expression of heat shock protein 70 and procollagen 1.
  
  
  RESULTS
  Pretreatment specimens contained solar damage. After treatment with the 1,064 nm Nd:YAG laser, the amount of collagen in the papillary dermis was slightly thicker than in those subjects treated with the IPL device (nonsignificant differences). Scattered dendritic cells in the papillary and upper reticular dermis expressed heat shock protein 70 and procollagen 1 after treatment with either light device.
  
  
  CONCLUSIONS
  Both the IPL and 1,064 nm Nd:YAG laser-induced heat activation of superficial dermal dendritic cells resulted in deposition of collagen in the papillary dermis without evident morphologic damage to the epidermis or dermis.
authors.affiliation: Departments of Pathology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas, USA.
authors.forename: Victor G
authors.initials: VG
authors.lastname: Prieto
authors.forename: A Hafeez
authors.initials: AH
authors.lastname: Diwan
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Shea
authors.forename: Peter
authors.initials: P
authors.lastname: Zhang
authors.forename: Neil S
authors.initials: NS
authors.lastname: Sadick
mesh_terms: D005260:Female; D006360:Heat-Shock Proteins / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D028022:Low-Level Light Therapy; D008875:Middle Aged; D010789:Phototherapy; D011347:Procollagen / Q000378:metabolism; D015595:Skin Aging / Q000473:pathology / Q000528:radiation effects*
chemical_list: D006360:Heat-Shock Proteins; D011347:Procollagen