A Two-Center, Open-Label, Randomized, Split-Face Study to Assess the Efficacy and Safety of One Versus Three Intradermal Injection Sites of AbobotulinumtoxinA in the Treatment of Lateral Periocular Rhytides

Background: Lateral canthal rhytides partly result from repetitive muscular actions of the orbicularis oculi. Objective: To determine the efficacy of one versus three injection sites of AbobotulinumtoxinA (ABO) in the treatment of lateral canthal rhytides. Methods: This was a two-center, evaluator-masked, 120 day study in which 40 patients with moderate to severe hyperdynamic lateral canthal rhytides at maximal contracture were randomized to receive one injection of 36 Units of ABO into the middle of the lateral orbital rhytides on one side, with the contralateral side treated with the same total dose of ABO, divided into three intradermal injections of 12 Units each, along the lateral canthal area. A blinded evaluator assessed lateral orbital rhytides at rest and maximal contraction at baseline, 7, 42, 90, and 120 days post treatment. Standardized digital photography and subject self-assessment were performed at each visit. Results: No statistically significant difference was seen at any visit between sides treated with one injection and those treated with three injections in any evaluation category. There was no difference in adverse events between the two sides. Conclusion: Sites treated with three injections of ABO showed no statistically significant difference from those treated with one injection.