Botulinum toxin type A therapy for blepharospasm.

• Cochrane Database Syst Rev. 2005

• BtA is superior to placebo as did large case-control and cohort studies, which reported that around 90% of patients benefited

• There are no high quality, randomised, controlled efficacy data to support the use of Bt for blepharospasm.

• Other studies suggest that BtA is highly effective and safe for treating blepharospasm and support its use.

• The effect size (90% of patients benefit) seen in open studies makes it very difficult and probably unethical to perform new placebo-controlled trials of efficacy of BtA for blepharospasm.

• Future trials should explore technical factors such as the optimum treatment intervals, different injection techniques, doses, Bt types and formulations.

• Other issues include service delivery, quality of life, long-term efficacy, safety, and immunogenicity.

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