[Botulinum toxin type A influence on the lacrimal function of patients with facial dystonia].

PURPOSE To analyze the influence of botulinum toxin on the lacrimal function of patients with facial dystonias. METHODS Patients with the diagnosis of hemifacial spasm or benign essential blepharospasm were evaluated and invited to answer the Ocular Surface Index Disease (OSID) questionnaire. All patients underwent Schirmer I and basal tests; break-up time (BUT) test and lacrimal clearance evaluation. On the following day, the patients were treated with botulinum toxin. The Ocular Surface Index Disease questionnaire and all the initial tests were reapplied 30 days after the treatment by the same examiner. RESULTS Twenty-six patients were enrolled in this study, 15 (57.7%) with hemifacial spasm and 11 (42.3%) with benign essential blepharospasm. The mean age of patients with hemifacial spasm was 70.9 ± 13.3 years and the male:female ratio was 1:1.5. In the group of patients with benign essential blepharospasm, the mean age was 68.9 ± 8.4 years with a female preponderance (90.0%). After the treatment, the Ocular Surface Index Disease score, Schirmer I and basal tests score decreased in both groups. The mean of Break-up time test increased significantly in both groups. The lacrimal clearance evaluation showed a greater number of eyes that achieved a complete drainage of the tears after the treatment in both groups. CONCLUSION The treatment with botulinum toxin improved dry eye symptoms in patients with facial dystonia. Despite of the aqueous portion of tear have decreased, blink modifications improved the tear stability and drainage.