Botulinum toxin-induced blepharoptosis: Anatomy, etiology, prevention, and therapeutic options.

Providers should understand the anatomy and be aware of the causes and treatment for blepharoptosis when injecting BoNT-A for the reduction of facial wrinkles. Thorough anatomic knowledge of the supraorbital area and orbital roof is paramount to preventing incorrect injection into "danger zones," which increase the risk of eyelid ptosis.