A Prospective Rater- and Subject-Blinded Study Comparing the Efficacy of IncobotulinumtoxinA and OnabotulinumtoxinA to Treat Crow's Feet

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). CONCLUSION: IncobotulinumtoxinA and onabotulinumtoxinA (1:1 dose conversion ratio) were well tolerated, showing comparable efficacy and duration of treatment effect for crow's feet.