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.