title: Pilot investigation of the correlation between histological and clinical effects of infrared fractional resurfacing lasers.
abstract: METHODS
  Yucatan Black pig skin was treated with a 1,540-nm erbium (Er):glass laser (Lux1540, 15 and 30 mJ) and two 1,550-nm Er-doped fiber lasers (Fraxel SR750 and SR1500, 8, 10, and 12 mJ). Histologic sections were examined to determine the depth of damage and to correlate subjects' clinical response. Concurrently, six subjects with photodamaged skin received three split-face and ipsilateral dorsal hand treatments with the 1,540-nm Er:glass laser on one side and one of the 1,550-nm Er-doped lasers (Fraxel SR750) on the other.
  
  
  RESULTS
  The 1,550-nm Er-doped lasers, using lower fluences and higher densities, produced shallower micro-columns than the 1,540-nm Er:glass device at higher fluences and lower densities (mean depths 250-275 microm vs 425-525 microm, respectively). Blinded assessors found greater overall improvement in pigmentation with the 1,550-nm Er-doped laser and better overall improvement in texture with the 1,540-nm Er:glass laser.
  
  
  CONCLUSIONS
  Greater densities of shallower damage columns at lower energies may better improve pigmentation, whereas deeper injuries, using higher energies and moderate densities, may better improve texture. This pilot study did not compare similar fluences and histologic damage between the two systems, and newer available systems allow for greater depth of penetration.
authors.affiliation: Zel Skin & Laser Specialists, Minneapolis, MN, USA.
authors.forename: Susan
authors.initials: S
authors.lastname: Walgrave
authors.forename: Brian
authors.initials: B
authors.lastname: Zelickson
authors.forename: James
authors.initials: J
authors.lastname: Childs
authors.forename: Gregory
authors.initials: G
authors.lastname: Altshuler
authors.forename: Andrei
authors.initials: A
authors.lastname: Erofeev
authors.forename: Ilya
authors.initials: I
authors.lastname: Yaroslavsky
authors.forename: David
authors.initials: D
authors.lastname: Kist
authors.forename: Jeff
authors.initials: J
authors.lastname: Counters
mesh_terms: D000328:Adult; D000818:Animals; D003357:Cosmetic Techniques; D005260:Female; D006801:Humans; D007259:Infrared Rays; D007834:Lasers; D008875:Middle Aged; D010865:Pilot Projects; D012867:Skin / Q000473:pathology* / Q000528:radiation effects*; D015595:Skin Aging / Q000528:radiation effects*; D013552:Swine