Long-term treatment of blepharospasm with botulinum toxin type A.

The treatment of essential blepharospasm with botulinum toxin has been known for a decade and is becoming increasingly more popular. To our knowledge, only a few longterm studies in major patient populations have been published. Of a total of more than 1,600 patients, results of treatment were evaluated in 115 patients (31 men and 84 women) treated continuously for a minimum of 3 years and a maximum of 8 years (mean, 5.7 years). Patients were divided into two groups. Group I represents the "good responders" and contains all patients who received only 4-10 injections over that time (n = 55). Group II represents the "poor responders, " who received at least 20 injections over that period (n = 60). Group I received a mean of 7.1 injections, whereas group II had a mean of 24.4 injections (total, 1,855). In group I the beneficial effect lasted for an average of 14.6 weeks (range, 2-52 weeks), whereas group II had a mean beneficial effect for only 6.8 weeks (range, 0-18 weeks). The time of efficacy remained statistically stable even in the case of frequent treatment (up to 36 injections in group II). Systemic or severe long-lasting local side effects were never observed; the most frequent side effects were: group I-ptosis, 5.4%; tearing, 5.1%; double vision, 1.8%; and lid lag, 1.5%; group II-ptosis, 4.3%; tearing, 3.3% lid lag, 1.9%, and double vision, 1.6%. The treatment of essential blepharospasm with botulinum toxin is a very effective therapy with minimal and transient complications. It may be used for long-term treatment without showing a decrease in efficacy.