Double vision due to lateral rectus injury after cosmetic botulinum toxin injections.

Facial intramuscular injections of Botulinum toxin (BoNT) injections are among the most common cosmetic procedures in dermatology. Rarely, serious adverse reactions such as blepharoptosis, diplopia and periorbital hematoma may occur with improper administration technique. Here we report a case of painless diplopia 5 weeks post-BoNT injection for 'crow's feet' likely due to inadvertent BoNT diffusion into the lateral rectus muscle causing a temporary palsy. This case aims to raise awareness of proper cosmetic BoNT injection techniques in the periorbital area to avoid ophthalmic complications.