Different injection patterns of incobotulinumtoxinA for crow's feet: a split-face comparative study.

BACKGROUND

IncobotulinumtoxinA has been previously used for the treatment of lateral periorbital lines (crow's feet). However, a standardized injection technique has not been established.

OBJECTIVES

To compare the efficacy and effect duration of two injection techniques of incobotulinumtoxinA for crow's feet treatment.

METHODS

Forty-eight patients with crow's feet were recruited and randomly assigned to receive bilateral treatments using either a 3-point intramuscular or a 6-point intradermal injection technique (8-12 units of incobotulinumtoxinA on each side). Improvement was assessed at 1, 2, 4, 8, 12, 16, 20 and 24 weeks postinjection. An objective evaluation was assessed by the indentation index using a 3D camera and a subjective evaluation was assessed by a blinded dermatologist using the Flynn validated assessment scale (FVAS) for the upper face. The patients assessed the results using the Global Aesthetic Improvement Scale (GAIS). Side-effects were evaluated at each visit.

RESULTS

After treatment, a significantly greater reduction in the indentation index of periorbital wrinkles on the 3-point intramuscular injection side compared with the 6-point intradermal injection side was observed at 8, 12, and 16 weeks. The results from the FVAS and GAIS scores showed significantly longer median times to relapse of the periorbital wrinkle for the 3-point intramuscular injection compared with the 6-point intradermal injection. Pain and bruising were slightly greater with the 6-point intradermal technique.

CONCLUSIONS

This study reaffirmed the efficacy of incobotulinumtoxinA for the treatment of crow's feet. The 3-point intramuscular injection technique yielded greater efficacy and longer duration of action than the 6-point intradermal injection technique.