Comparison of preseptal and pretarsal injections of botulinum toxin in the treatment of blepharospasm and hemifacial spasm

Although the beneficial effect of subcutaneous injections of botulinum toxin type A (BTX-A) is well known in both blepharospasm and hemifacial spasm, the position of the injection sites around the orbicularis oculi may influence the effectiveness and side effects. Here we report results of preseptal and pretarsal BTX-A injections in 53 patients (25 blepharospasm and 28 hemifacial spasm) in whom we used both injection techniques successively. Pretarsal injections were used in 102 out of 186 treatments in blepharospasm group and in 84 out of 202 treatments in hemifacial spasm group. Pretarsal BTX-A treatment produced significantly higher response rate and longer duration of maximum response in both patient groups. This technique was also associated with a lower frequency of major side effects such as ptosis. We concluded that injections of BTX-A into the pretarsal, rather than the preseptal portion of the orbicularis oculi is more effective for treatment of involuntary eyelid closure due to contractions of this muscle.