title: Fractional CO2 laser for the treatment of acne scars.
abstract: BACKGROUND
  Numerous reports have been published on skin rejuvenation by the so-called fractional laser device that delivers a laser beam in a dot form over a grid pattern.
  
  
  OBJECTIVE
  In this study, we characterized the effects of a fractional CO(2) laser on atrophic acne scars at the clinical and ultrastructural levels.
  
  
  METHODS
  Seven healthy adult Japanese volunteers (aged 32-46 years, mean 37.6, five men and two women of Fitzpatrick skin type III) were recruited for this study. A fractional CO(2) laser device, SmartXide DOT (DEKA, Florence, Italy), was used with irradiation parameters set as follows: output power 10 W, pulse width 600 μs, dot spacing 800 μm, and stack 2 (irradiation output power 0.91 J/cm(2) ). A clinical examination and punch biopsy of each subject was performed before and just after the irradiation, and also at week 3 after three irradiation sessions. The biopsy specimens were stained with toluidine blue and were examined ultrastructurally.
  
  
  RESULTS
  Clinical improvement of the atrophic acne scars was observed at week 3 after the third irradiation session in all cases compared with the condition before treatment. Histologically, outgrowths of many degenerated elastic fibers were observed as irregular rod-shaped masses in the superficial dermis prior to the treatment in the region of the acne scars. At week 3 after the third irradiation, the degenerated elastic fibers were no longer observed, and the elastic fibers were elaunin-like.
  
  
  CONCLUSIONS
  The fractional CO(2) laser is considered to be very effective for treating atrophic acne scars.
authors.affiliation: Department of Dermatology, Queen's Square Medical Center, Yokohama, Japan. t.omi@queens-sq.or.jp
authors.forename: Tokuya
authors.initials: T
authors.lastname: Omi
authors.forename: Seiji
authors.initials: S
authors.lastname: Kawana
authors.forename: Shigeru
authors.initials: S
authors.lastname: Sato
authors.forename: Paolo
authors.initials: P
authors.lastname: Bonan
authors.forename: Zenya
authors.initials: Z
authors.lastname: Naito
mesh_terms: D000152:Acne Vulgaris / Q000150:complications*; D000328:Adult; D001284:Atrophy; D001706:Biopsy; D002921:Cicatrix / Q000209:etiology / Q000473:pathology* / Q000601:surgery*; D020405:Dermis / Q000473:pathology / Q000528:radiation effects / Q000648:ultrastructure; D019583:Dose Fractionation, Radiation; D005260:Female; D006801:Humans; D053685:Laser Therapy; D054020:Lasers, Gas / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged