The use of botulinum toxin in blepharospasm.

Twenty-two patients, 17 with benign essential blepharospasm and five with hemifacial spasm, received botulinum toxin by subcutaneous injections in the eyelids and eyebrows. All 22 patients received a standard treatment of 12.5 units of botulinum toxin per side at each injection session. The orbicularis oculi muscle showed pronounced weakness after injection and the spasms decreased. Spasms often recurred despite persistent orbicularis oculi muscle weakness. Side effects were minimal. All patients received some relief, which generally lasted six to 12 weeks.