First used and approved over a decade ago for the treatment of strabismus (or misaligned eyes), botulinum toxin (BTX) has demonstrated efficacy in blepharospasm, hemifacial spasm, spastic lower eyelid entropion, and a number of other disorders seen in the traditional medical environment that are characterized by abnormal muscle contraction. Moreover, other conditions-notably some pain and gastrointestinal disorders-have responded to BTX injections.