Botulinum toxin increases tearing in patients with Sjögren's syndrome: a preliminary report.

Three patients with Sjögren's syndrome (SS) who had severe xerophthalmia and blepharospasm received botulinum toxin injections for the treatment of their blepharospasm. They had a remarkable increase in tearing, measured by Schirmer's test, and a decrease in signs and symptoms of dry eyes after botulinum toxin injection periorbitally for blepharospasm. The mechanism for this increased tearing is unclear, but suggests a potential treatment for patients with severe xerophthalmia with SS.