title: A prospective rater- and subject-blinded study comparing the efficacy of incobotulinumtoxinA and onabotulinumtoxinA to treat crow's feet: a clinical crossover evaluation.
abstract: BACKGROUND
  Botulinum toxin A products have been used in aesthetics for more than 20 years.
  
  
  OBJECTIVE
  To compare incobotulinumtoxinA with onabotulinumtoxinA in the treatment of crow's feet.
  
  
  METHODS
  This single-center, randomized, prospective, split-face, subject- and rater-blinded study with a clinical crossover evaluation comprised 2 consecutive treatment cycles, each of 3 months' duration separated by 6 months (i.e., a 9-month treatment interval). Fourteen subjects with symmetrical crow's feet were assessed using the Merz 5-point scale for crow's feet, after each treatment with incobotulinumtoxinA (right side of the face) and onabotulinumtoxinA (left side), or vice versa (1:1 dose conversion ratio). The treatment applied to each side of the face was reversed in Cycle 2.
  
  
  RESULTS
  Crow's feet severity at rest and maximum contraction was improved to a similar extent by both treatments, in both cycles and on both sides of the face. Pooled data confirmed these results. Improvements were maintained at the final visit, 3 months after treatment (e.g., left side at maximum contraction-onabotulinumtoxinA mean score: 2.21 [baseline] vs 0.93 [1 month] vs 1.71 [3 months]; incobotulinumtoxinA mean score: 2.21 vs 0.86 vs 1.50).
  
  
  CONCLUSIONS
  IncobotulinumtoxinA and onabotulinumtoxinA (1:1 dose conversion ratio) were well tolerated, showing comparable efficacy and duration of treatment effect for crow's feet.
authors.affiliation: *Dipartimento di Chirurgia Plastica, Istituto Dermatologico Europeo, Milano, Italy; †Scientific Communications and Information, Oxford, United Kingdom.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Muti
authors.forename: Laura
authors.initials: L
authors.lastname: Harrington
mesh_terms: D000328:Adult; D019274:Botulinum Toxins, Type A / Q000627:therapeutic use*; D018592:Cross-Over Studies; D005123:Eye; D005260:Female; D006801:Humans; D008875:Middle Aged; D009465:Neuromuscular Agents / Q000627:therapeutic use*; D011446:Prospective Studies; D016037:Single-Blind Method; D015595:Skin Aging / Q000187:drug effects*
chemical_list: D009465:Neuromuscular Agents; D019274:Botulinum Toxins, Type A; C545476:incobotulinumtoxinA