A double-blinded, randomized, placebo-controlled pilot study of the safety and efficacy of Myobloc (botulinum toxin type B)-purified neurotoxin complex for the treatment of crow's feet: a double-blinded, placebo-controlled trial.

Crow's feet develop with age and are one of the earliest signs of the normal aging process. Botulinum toxin type A, approved by the Food and Drug Administration for the treatment of glabellar wrinkles in April 2002, has been used off-label to treat facial wrinkles since 1981. Botulinum toxin type B (BTX-B, Myobloc) was Food and Drug Administration-approved for use in cervical dystonia in the United States in December 2000 and has subsequently been used in an off-label indication to treat facial wrinkles. There are sparse data in the literature evaluating the safety and efficacy of BTX-B for the treatment of facial wrinkles. In this pilot study, participants with moderate or severe crow's feet wrinkles were treated with Myobloc versus placebo. The duration of correction and side effect profile are reported.