A new study published online in Archives of Facial Plastic Surgery suggests Dysport (abobotulinumtoxinA) is better for treating Crow’s feet than Botox (onabotulinumtoxinA).
Let’s look at the study which only had 90 patients, all older than 18 years of age (mean age 54½, 77 women), were enrolled in a randomized, double-blind, split-face study.
The authors include this history of both products:
….in 2002, the FDA approved Botox Cosmetic (onabotulinumtoxinA) (Allergan Inc, Irvine, California) for the treatment of corrugator-mediated glabellar lines.
Concurrently, another botulinum toxin type A product manufactured by Medicis Aesthetics (Scottsdale, Arizona), Dysport (abobotulinumtoxinA), had been used in other countries since 1991. It was approved for cosmetic use in Europe in 2001, before being approved by the FDA in April 2009 for the treatment of moderate-to-severe glabellar lines.
Today, the cosmetic applications for onabotulinumtoxinA and abobotulinumtoxinA have expanded to the treatment of hyperfunctional lines related to the orbicularis oculi, frontalis, transverse nasalis, and depressor anguli oris, among other muscle groups.
The 90 patients were seen and treated between December 2009 to August 2010. To be included in the study, the men (n=13) and women (n=77) had to have moderate to severe lateral orbital rhytids at maximal contraction and NOT had botulinum neuromodulator treatment to the crow's feet within the prior 6 months.
Other exclusion criteria included: prior face-lift, brow-lift, or blepharoplasty; prior periocular laser or chemical resurfacing; prior adverse reaction associated with botulinum neuromodulator; or a history of degenerative neuromuscular diseases.
Each of the 90 participants were photographed prior to treatment and during each subsequent follow-up visit (posttreatment days 2, 4, 6, and 30).
A standard 5-view photographic series was taken for each patient at rest and at maximal contraction.
Patients and investigator separately assessed the crow’s feet at rest and at maximal contraction on each side, according to a validated 5-point photographic scale (0, no wrinkles; 1, very fine lines; 2, fine lines; 3, moderate wrinkles; and 4, severe wrinkles). This assessment was done prior to treatment and at each follow-up visit. (photo credit)
The treatment consisted of 10 U of Botox on one side of the face while the contralateral side received 30 U of Dysport with treatment sides of the face being randomized by computer-aided software. The recommended dosage ratio of Dysport to Botox varies from 5:1 to 3:1. The article sites the reason for this dosage “recent studies and the clinical experience of the senior investigator point to a 3:1 ratio as being optimal.”
Sixty-seven percent of patients preferred the side treated with Dysport, while 33% of patients chose the side treated with Botox. This difference was statistically significant (P = .002).
On post-treatment day 30, the investigator-assessed efficacy score at maximal contraction averaged 2.60 for the Dysport-treated side of the face and 2.33 for the Botox-treated side (P=0.01).
However, two other secondary end points, investigator and patient assessments of resting lateral orbital rhytids, did not achieve statistical significance (P = .42 and P = .28, respectively).
I would say this is a start in determining which might be better, but it needs to be remembered that this is a very small study and has not been duplicated.
An Internally Controlled, Double-blind Comparison of the Efficacy of OnabotulinumtoxinA and AbobotulinumtoxinA; Kartik D. Nettar, Kenneth C. Y. Yu, Sumit Bapna, John Boscardin, Corey S. Maas; Arch Facial Plast Surg. 2011;Published online June 20, 2011. doi:10.1001/archfacial.2011.37