[Lacrimal film evaluation of patients with facial dystonia during botulinum toxin type A treatment].

Purpose: To determine the effect of botulinum toxin injection in the eyelid on lacrimal film in patients with facial dystonia.

Methods: Twenty-four patients with essential blepharospasm and hemifacial spasm were submitted to botulinum toxin injection and lacrimal film tests were performed before the application and after seven and thirty days.

Results: There was improvement in symptoms of dry eye and rose bengal test, however, the breakup time and Schirmer's test did not show significant variation between pretreatment and after 1 month of follow-up.