ACQUIRED BLEPHAROPTOSIS SECONDARY TO ESSENTIAL BLEPHAROSPASM

We treated four patients with essential blepharospasm, receiving botul inum A toxin, in whom, although they had no preexisting blepharoptosis , a concurrent bilateral acquired blepharoptosis developed. Since the blepharoptosis did not improve after the period of time during which t he effects of botulinum A toxin would have been expected to resolve (2 to 10 weeks), we judged that its development was unrelated to the tox in. We propose, rather, that the stretching, attenuation, disinsertion , or dehiscence of the upper eyelid levator muscle caused by the bleph arospasm were at least partly responsible for the onset of the blephar optosis. To ensure appropriate treatment in these cases, careful clini cal evaluation is required to differentiate the two conditions.