Effect of upper eyelid myectomy on subsequent chemodenervation in the management of benign essential blepharospasm

Some patients with severe benign essential blepharospasm (BEB) become clinically refractory to chemodenervation with botulinum toxin. In these patients, surgical myectomy is an effective additive treatment for the management of this disabling condition. The purpose of this study is to determine how myectomy for BEB alters subsequent botulinum toxin administration.

A retrospective chart review of 27 patients undergoing surgical myectomy for the treatment of refractory BEB was conducted. The frequency and dosage of botulinum toxin were compared between preoperative and postoperative treatments. Paired Student t tests were used to determine significance (α = 0.05).

The mean interval between botulinum treatments was 10.1 weeks preoperatively and 15.7 weeks postoperatively (p < 0.001). The mean quantity of botulinum toxin administered was 68 units prior to myectomy and 64.9 units postoperatively (p = 0.227). When comparing the quantity of botulinum toxin injected into the upper eyelid region only (site of myectomy), there was a significant decrease in the dose administered preoperatively and postoperatively (46.8 units vs. 39.9 units, p = 0.00310).

Upper eyelid myectomy is an effective treatment modality for BEB in those patients who are refractory to botulinum toxin injections. Myectomy for BEB decreases the morbidity, botulinum toxin treatment frequency, and long-term expense associated with this disabling condition.