ABSTRACT
Assuming that botulinum toxin injection can release the involuntary contraction as well as reduce the tear drainage function, mediated by paralysis of orbicularis oculi muscles, then give rise to effect on tear clearance, Authors have examined 18 blepharospasm and 32 hemifacial spasm patients to evaluate the pre- and post- botulinum toxin injectional values of BUT, Schirmer test, and fluolescein clearance test 1, 2, which evaluate possibilities of delayed tear clearanee induced by botulinum toxin injection. Following treatment with botulinum toxin, results of BUT were increased significantly (p<0.0001), values of Schirmer test tended to increase without statistical significance. In fluorescein clearance test 1, length and concentration values were increased significantly(p<0.05), but in fluorescein clearance test 2, only length measurements were increased significantly(p<0.05). And also in blepharospasm cases of BUT values less than 4 second, both Schirmer test and fluorescein clearance test results were increased with statistical significance(p<0.05). We concluded that delayed tear clearance induced by botulinum toxin injection could be effective treatment for facial dystonias, especially combined cases with dry eye.