title: Effect of pulse width of a variable square pulse (VSP) erbium:YAG laser on the treatment outcome of periorbital wrinkles in Asians.
abstract: BACKGROUND
  Uses of appropriate laser parameters are essential for an optimum outcome with minimal risks of complications.
  
  
  OBJECTIVE
  To evaluate the effect of pulse width of a variable square pulse (VSP) Er:YAG laser on the treatment outcome.
  
  
  METHODS
  Twenty-four Thais with periorbital wrinkles received two treatments with a low-fluence, VSP Er:YAG laser resurfacing 1 month apart. Subjects were randomly divided into two groups and treated with two different parameters including a pulse width of 0.3 ms (short pulse, SP) for one group and a pulse width of 250 ms (super-long pulse, SL) for the other group. Assessments were evaluated at baseline, 1-month and 3-month follow-up visits.
  
  
  RESULTS
  After one treatment, 63.7% and 33.4% of the subjects in the SP and SL groups, respectively, were assessed to have obvious to marked improvement of their wrinkles. After two treatments, a higher percentage of the subjects were rated to have obvious to marked improvement including 91% and 66.7% in the SP and SL groups, respectively. There was no significant difference in therapeutic outcome between the SP and SL groups.
  
  
  CONCLUSIONS
  There was no significant difference in efficacy and side effects, between the SP and SL groups. However, a trend toward better response with the shorter pulse width was observed.
authors.affiliation: Department of Dermatology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand. siwmn@mahidol.ac.th
authors.forename: Woraphong
authors.initials: W
authors.lastname: Manuskiatti
authors.forename: Sujittra
authors.initials: S
authors.lastname: Siriphukpong
authors.forename: Supenya
authors.initials: S
authors.lastname: Varothai
authors.forename: Rungsima
authors.initials: R
authors.lastname: Wanitphakdeedecha
authors.forename: Richard E
authors.initials: RE
authors.lastname: Fitzpatrick
mesh_terms: D000328:Adult; D004954:Esthetics; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053685:Laser Therapy / Q000379:methods*; D053844:Lasers, Solid-State / Q000627:therapeutic use*; D008875:Middle Aged; D010149:Postoperative Pain / Q000503:physiopathology; D017060:Patient Satisfaction; D011182:Postoperative Care / Q000379:methods; D012060:Rejuvenation; D018570:Risk Assessment; D015595:Skin Aging; D013785:Thailand; D016896:Treatment Outcome