The effect of omitting botulinum toxin from the lower eyelid in blepharospasm treatment

We randomly selected 26 patients with essential blepharospasm to receive either botulinum toxin or saline injection in their lower eyelids to evaluate the necessity of lower eyelid injection to relieve blepharospasm. As diplopia may occur from botulinum toxin injections for blepharospasm, most commonly from injection of the lower eyelid, and surgical relief of blepharospasm is often achieved by excision of only the upper eyelid protractors, omission of toxin from the lower eyelid seemed both desirable and possible. All patients received botulinum toxin in the upper eyelids, above the eyebrows, across the glabella, and near the lateral canthus. Thirteen of 15 patients who received saline in their lower eyelids had relief of spasm, with the same spasm-free interval as those who received toxin. We recommend avoiding injection of toxin in the medial two thirds of the lower eyelid in order to diminish the likelihood of diplopia from inferior oblique muscle paresis.