Supramaximal Doses of Botulinum Toxin for Refractory Blepharospasm

Purpose: To investigate the response to supramaximal doses of botulinum toxin in patients with refractory blepharospasm. Design: Prospective, nonrandomized, open-label interventional case series. Participants: Eight consecutive patients with blepharospasm requiring injections every 2 months despite receiving 100 U of botulinum toxin per session. Intervention: Increasing the dose of botulinum toxin per session above the conventional maximum. Main Outcome Measures: Duration of treatment effect and patients' subjective response to treatment. Results: Supramaximal dosages were well tolerated. Seven of 8 patients had a prolonged interval between injections relative to that associated with their previous dosing regimen. Four of the patients elected to continue with the new dosage. Conclusion: In select patients with essential blepharospasm who are refractory to standard treatment regimens, increasing the dosage of botulinum toxin above 100 U per session may decrease the interval between injections, improve the patient's quality of life, or both.