Efficacy and Safety of Long-Term Therapy with Type A Botulinum Toxin in Patients with Blepharospasm

Blepharospasm (BPS) is one of the most frequent types of facial dystonia and, at the same time, one of the most disabling, being able to trigger functional blindness if not treated. Our aim with this work was to evaluate the efficacy and safety of long-term onabotulinum A toxin (BAT) treatment in a cohort of patients with BPS. The retrospective study was conducted on consecutive patients with BPS treated with subcutaneous BAT. The selection of muscles and dose was made based on each patient's needs. The clinical and demographic characteristics, number of sessions, dose, duration and effectiveness of treatment, and adverse events were analysed. 130 patients were included in the study. The median (95% confidence interval) length of follow-up was 14 (13-15.6) years with an average of 20.5 sessions (range from 10 to 57). Regarding the efficacy of the treatment, 114 (87.7%) experienced satisfactory results with functional and aesthetics recovery. Patient evaluation of global response suggested a clear improvement without adverse events in 72 (55.4%) patients. Adverse events developed at least once during the treatment in 39% of patients, with transient ptosis and haematoma the most common reported both by physician and patient. The results of our study suggest that botulin toxin A is a safe and effective long-term treatment for blepharospasm with mild, transient and well-tolerated side effects when they appear.