Long-term results and complications of botulinum A toxin in the treatment of blepharospasm.

The authors review their long-term results and complications with the use of botulinum A toxin in the treatment of facial dystonias. Two hundred thirty-two patients in three diagnostic groups--essential blepharospasm, hemifacial spasm, and Meige's syndrome--were treated with botulinum A toxin. A total of 1044 treatments were given over a 4-year period. A reduction in orbicularis spasm intensity was noted in 1012 (96.9%) treatments (mean duration, 13.3 weeks). There was no clear relationship between toxin dose and the amount of spasm reduction or duration of response, and average duration of beneficial effect remained constant from the first through the twelfth injections. Complications occurred in 236 (22.6%) treatments. In most cases, these were local and transient. Symptomatic dry eye was the most common side effect, noted in 7.5% of cases. Ptosis was reported in 7.3% of treatments and photophobia in 2.5%. Diplopia involving the inferior oblique or lateral rectus muscles was seen in less than 1% of cases. There were no differences in degree of response or in complications among the three diagnostic groups, although there was a slight difference in duration of effect. Patients who had undergone previous eyelid surgery for blepharospasm did not respond differently from those without prior surgery.