A Prospective Assessment of Biomechanical Changes in Skin after the Injection of Onabotulinum Toxin

Abstract

Objectives:

Although primarily used as a neuromodulator, a recent case series suggests that botulinum toxin A (onabotulinum) may also improve skin elasticity. The purpose of this study was to test the hypothesis that the administration of onabotulinum for lateral orbital and glabellar rhytides will result in an increase in patient’s skin elasticity and reduce the pliability.

Methods:

Forty patients were prospectively enrolled for administration of onabotulinum to their lateral orbit and glabella. To assess skin biomechanics, we used the Cutometer MP580. All patients were assessed pre-treatment and at 2-weeks and 2-months post-treatment. An analysis of variance (ANOVA) with repeated measures was used to assess for differences between assessments.

Results:

There was a significant increase in both skin elasticity (f = 46.9, P = 0.001) and pliability (f=46.8, P < 0.001) with a mean (+/-SE) increase in elastic recoil of the skin by 20% (4.4%) for the glabellar region (P < 0.001) and 18% (4.0%) for the lateral orbit (P < 0.0001) while there was an increase in skin pliability of 26% (5.4%) for the lateral orbit (P = 0.001) and 52% (8.3%) for the glabellar region (P < 0.001). There was no significant difference on the patients forearm (control site) for both elasticity (P = 0.57) and pliability (P = 0.16).

Conclusions:

Injection of onabotulinum results in skin that has increased pliability as well as increased elastic recoil. Although this study demonstrates the positive effect of onabotulinum on skin elasticity, it is unclear whether this is due to specific histological changes.