Prospective randomized controlled study to determine the effect of topical application of botulinum toxin A for crow's feet after treatment with ablative fractional CO2 laser.

Background: Botulinum toxin Type A (BoNT A) for the treatment of facial wrinkles is delivered through local injection. We previously demonstrated that topical surface application of BoNT A has negligible cutaneous bioavailability and is not effective in treating wrinkles.

Objective: To determine the effect of BoNT A solution applied topically on the skin surface immediately after ablative fractional CO2 laser treatment.

Methods: We conducted a randomized controlled trial for patients with periorbital wrinkles (crow's feet) (n = 10). Treatment was performed on both sides of the face with fractional ablative CO2 laser followed by the application of topical solutions of BoNT A on one side and normal saline as control on the other side. Pretreatment assessment was performed, and at 1 and 4 weeks after treatment.

Results: There was a clinically significant greater degree of improvement in wrinkles after treatment with CO2 laser, on the topically applied BoNT A side. Also, the difference between the 2 treatment types (laser followed by topical BoNT A vs laser followed by saline) at 1 week and at 1 month was statistically significant.

Conclusion: Topically, noninjectable form of BoNT A applied on the surface of the skin after ablative fractional CO2 laser is effective in the treatment of lateral periorbital wrinkles.