Treatment of mild to moderate blepharospasm. Injection of the pretarsal and preseptal portion of the orbicularis muscle. Typical initial doses consist of 2.5 units of botulinum toxin A to the medial and lateral aspect of the upper eyelid along the eyelid crease. Since the skin is only 60 microns thick in this region, the injection is given subcutaneously to avoid penetrating the underlying septum and inducing ptosis of the upper eyelid.