Comparison of classic vs double concentrated dose botulinum toxin injections in the treatment of crow's feet.

[BACKGROUND] When it comes to administering botulinum toxin for treating rhytids, a standard approach is usually used by most providers in terms of dose concentration. The aim of this study is to compare the outcomes of a classic, none double concentrated dose vs. a double concentrated dose for treating crow's feet.

[METHOD] We have injected the orbicularis oculi in a series of 10 patients with the left side as a control side using the classically concentrated dose (2 units per 0.5cm) compared to the double concentrated dose on the right (2 units per 0.25cm). The injections were administered using an auto-injecting syringe.

[RESULTS] On control day 14, we noticed that the majority of patients had a more apparent reduction in wrinkles on the left-classically concentrated-side (wrinkling appeared to be more prominent on the double concentration right side). A benefit noticed in some patients was a more symmetrical appearance of periorbital rhytids and sometimes the eyebrows with the uneven doses.

[CONCLUSION] We found that injecting a double concentrated dose of botulinum toxin does not necessarily mean better reduction in the appearance of wrinkles even with the retrograde injection technique. However, certain implications may be found in tailoring the dosing of botulinum toxin depending on the needs of the patient on opposite sides of the face as opposed to unifying the dose for both sides.