title: Safety study of transcutaneous focused ultrasound for non-invasive skin tightening in Asians.
abstract: OBJECTIVE
  Transcutaneous intense focused ultrasound has emerged as a novel technology for non-invasive skin tightening. The objective of this study was to evaluate the safety profile of a transcutaneous focused ultrasound device for the treatment of facial skin laxity in Asians.
  
  
  METHODS
  The patients received one to three full-face treatments with the transcutaneous focused ultrasound device. Three transducers (7.0 MHz, 3.0 mm focal depth; 7.0 MHz, 4.5 mm focal depth; 4.0 MHz, 4.5 mm focal depth) were used to deliver a single pass of microthermal coagulation zones without any topical anesthetics. Standardized photos were taken at baseline and at each follow-up with the Canfield Visia CR system® and were assessed by two independent physicians. Adverse effects were assessed up to 6 months post treatment. Subjective assessments in terms of pain and tolerability were also evaluated with patient questionnaires.
  
  
  RESULTS
  Forty nine Chinese patients (skin types III-IV, mean age 53.3) completed a total of 68 treatment sessions. Transient erythema and edema were seen in the majority of patients. Focal bruising was present in up to 25% of treatment sessions. Two cases of post-inflammatory hyperpigmentation were seen on the forehead at 1-month post-treatment. One patient experienced focal twitching over the lower eyelid at 1-month follow-up, which was clinically consistent with hemifacial spasm and was unrelated to the ultrasound device. The degree of pain during treatment was recorded as severe in 54.4% of treatment sessions.
  
  
  CONCLUSIONS
  Transcutaneous intense focused ultrasound appeared to be safe for non-invasive facial skin tightening in Asians. Adverse events were mild and transient. Pain control during treatment should be optimized. No serious permanent or delayed side effects were noted up to 6 months post treatment.
authors.affiliation: Division of Dermatology, Department of Medicine, University of Hong Kong, Hong Kong SAR, China.
authors.forename: Nicola P Y
authors.initials: NP
authors.lastname: Chan
authors.forename: Samantha Y N
authors.initials: SY
authors.lastname: Shek
authors.forename: Carol S
authors.initials: CS
authors.lastname: Yu
authors.forename: Stephanie G Y
authors.initials: SG
authors.lastname: Ho
authors.forename: Chi K
authors.initials: CK
authors.lastname: Yeung
authors.forename: Henry H L
authors.initials: HH
authors.lastname: Chan
mesh_terms: D000328:Adult; D044466:Asian People; D002681:China; D003357:Cosmetic Techniques / Q000009:adverse effects / Q000295:instrumentation; D005145:Face / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012867:Skin / Q000000981:diagnostic imaging*; D015595:Skin Aging / Q000208:ethnology*; D014159:Transducers; D016896:Treatment Outcome; D014464:Ultrasonic Therapy / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods*; D014463:Ultrasonography