title: A preliminary clinical and histopathological study of laser skin resurfacing using a frequency-doubled Nd:YAG laser after application of Chromofilm.
abstract: OBJECTIVE
  Carbon dioxide (CO2) and Er:YAG lasers are commonly used for laser skin resurfacing. In demonstrating their efficacy, intra- and interoperator variability may be important. In attempting to solve this problem, a new concept was developed which combines a previous application of an exogenous chromophore onto the skin in a standardized way (Chromofilm) and irradiation with a millisecond, low-power pulsed laser.
  
  
  METHODS
  This study aimed to evaluate this new concept in vivo in human skin using a 532-nm Nd:YAG laser connected to a scanner using the following parameters: 532 nm, 2W, 1-mm spot size, 30-mm2 hexagonal surface irradiation and 50-120-ms pulse duration. The laser irradiation was performed both 15 h and 1 h prior to the facelift procedure. Tissue samples were examined histologically to determine the injury depth using nitroblue-tetrazolium chloride (NBTC) staining, haematoxylin-eosin staining and Masson's staining.
  
  
  RESULTS
  Morphometric analysis of histological preparations showed that the depth of injury was dose-dependent: 50-ms pulse duration induced total epidermis ablation and fine dermal coagulation; 120-ms pulse duration induced dermal coagulation down to 120 microns. No residual carbon film was observed on histologic sections.
  
  
  CONCLUSIONS
  Laser skin resurfacing using a 532-nm laser irradiation after application of a carbon film transfer is an effective method for skin resurfacing. With this new galenic approach (Chromofilm), the control of all parameters (thickness, chromophore concentration and distribution) can be achieved to predict the thermal injury obtained after laser irradiation.
authors.affiliation: GALDERMA Research and Development, Sophia Antipolis, France.
authors.forename: C C
authors.initials: CC
authors.lastname: Sumian
authors.forename: F B
authors.initials: FB
authors.lastname: Pitre
authors.forename: B E
authors.initials: BE
authors.lastname: Gauthier
authors.forename: J L
authors.initials: JL
authors.lastname: Levy
authors.forename: M
authors.initials: M
authors.lastname: Bouclier
authors.forename: S R
authors.initials: SR
authors.lastname: Mordon
mesh_terms: D002056:Burns / Q000209:etiology / Q000473:pathology; D006801:Humans; D017075:Laser Coagulation / Q000009:adverse effects / Q000379:methods*; D009354:Neodymium; D011095:Polyethylenes; D015361:Rhytidoplasty / Q000379:methods*; D012867:Skin / Q000473:pathology; D013997:Time Factors
chemical_list: C430323:Chromofilm; D011095:Polyethylenes; D009354:Neodymium