A randomized, evaluator-blinded, two-center study of the safety and effect of volume on the diffusion and efficacy of botulinum toxin type A in the treatment of lateral orbital rhytides.
BACKGROUND
There has been considerable discussion about the effect of the degree of dilution of botulinum toxin (BTX) but very few scientific studies.


OBJECTIVE
The objective was to observe as to whether a fivefold difference in concentration of BTX solution would produce a difference in clinical effect or duration of effect.


METHODS
Twenty individuals were enrolled at two sites and a within-subject paired-comparison study was performed on the lateral orbital area with a single injection of 5 U of BTX (BOTOX Cosmetic, Allergan Inc., Irvine, CA). The results were assessed both clinically and using a computer-assisted estimation of the degree of wrinkling.


RESULTS
No statistically significant differences were observed between the two sides.


CONCLUSIONS
This is a small study and it may be that dilution does affect BTX result. We were, however, unable to detect any difference in this study, which suggests that the degree of dilution, at least within a fivefold margin, has only a small effect on the results of BTX injection in the lateral orbital area.
Carruthers
Alastair
A
Department of Dermatology, University of British Columbia, Vancouver, British Columbia, Canada. alastair@carruthers.net
Bogle
Melissa
M
Carruthers
Jean D A
JD
Dover
Jeffrey S
JS
Arndt
Kenneth A
KA
Hsu
Te-Shao
TS
Poirier
Jude
J
D019274:Botulinum Toxins, Type A / Q000008:administration & dosage / Q000627:therapeutic use*; D001955:British Columbia; D004311:Double-Blind Method; D005148:Facial Dermatoses / Q000188:drug therapy* / Q000473:pathology; D005260:Female; D006801:Humans; D007279:Injections, Subcutaneous; D008875:Middle Aged; D009465:Neuromuscular Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D012720:Severity of Illness Index; D015595:Skin Aging; D016896:Treatment Outcome; D014481:United States
D009465:Neuromuscular Agents; D019274:Botulinum Toxins, Type A