title: An in vivo trial comparing the clinical efficacy and complications of Q-switched 755 nm alexandrite and Q-switched 1064 nm Nd:YAG lasers in the treatment of nevus of Ota.
abstract: BACKGROUND
  Q-switched 755 nm alexandrite (QS alex) and Q-switched 1064 nm Nd:YAG lasers are effective in the treatment of nevus of Ota. Our previous in vivo study indicated that patients better tolerate QS alex than QS 1064 nm Nd:YAG laser. However, in terms of clinical efficacy and long-term complications, the study did not indicate which laser is superior. Although both machines may appear to be similar in effectiveness, the low number of treatment sessions may contribute to this apparent lack of difference.
  
  
  OBJECTIVE
  The aim of this study was to compare the clinical efficacy and complications of QS 755 nm alex and QS 1064 nm Nd:YAG lasers in the treatment of nevus of Ota after three or more treatment sessions.
  
  
  METHODS
  Forty patients were recruited for this study and all had received three or more laser treatment sessions with an interval of at least 2 months between each. Half of the lesion was treated with QS alex and the other half with QS 1064 nm Nd:YAG laser. The degree of lightening was assessed subjectively by the patient using a visual analog scale and objectively by two independent clinicians. Patients were called back to be examined for evidence of complications.
  
  
  RESULTS
  In terms of subjective degree of lightening, QS 1064 nm Nd:YAG laser was found to be significantly more efficacious than QS alex (P = 0.018). Both clinicians also found QS 1064 nm Nd:YAG laser to be more effective, but statistical significance was only detected in one, not both of their scores (P = 0.005 and 0.414 for observers 1 and 2, respectively). More patients that received QS Alex developed complications (4 for QS alex and 2 for QS Nd:YAG), but the difference was not statistically significant.
  
  
  CONCLUSIONS
  QS 1064 nm Nd:YAG laser appears to be more effective than QS alex in the lightening of nevus of Ota after three or more laser treatment sessions. However, the majority (55%) of the patients reported no differences in results between the two lasers, and only one of the two observers noted statistically significant improvement of QS 1064 nm Nd:YAG over QS alex.
authors.affiliation: Division of Dermatology, Department of Medicine, University of Hong Kong, Prince of Wales Hospital, Hong Kong. hhlchan@hkucc.hku.hk
authors.forename: H H
authors.initials: HH
authors.lastname: Chan
authors.forename: S Y
authors.initials: SY
authors.lastname: Ying
authors.forename: W S
authors.initials: WS
authors.lastname: Ho
authors.forename: T
authors.initials: T
authors.lastname: Kono
authors.forename: W W
authors.initials: WW
authors.lastname: King
mesh_terms: D000293:Adolescent; D000328:Adult; D001608:Beryllium / Q000627:therapeutic use*; D002648:Child; D005145:Face; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053685:Laser Therapy; D007834:Lasers / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D009354:Neodymium / Q000627:therapeutic use*; D009507:Nevus of Ota / Q000175:diagnosis / Q000601:surgery*; D011446:Prospective Studies; D012878:Skin Neoplasms / Q000188:drug therapy / Q000601:surgery*; D018709:Statistics, Nonparametric; D016896:Treatment Outcome
chemical_list: C112654:alexandrite; D009354:Neodymium; D001608:Beryllium