The diagnosis of apraxia of eyelid opening is tricky from a clinical point of view. The essential feature is a failure of the levator muscle to raise the upper lid, but the levator cannot be seen with just clinical obbservation. The diagnosis can be made definitively using electromyography (EMG) using a small needle electrode to record from the muscle, and to observe directly that it is not contracting appropriately. This, however, is not frequently undertaken. In pure cases of apraxia of eyelid opening, the eyelids remain closed solely because of levator failure. Neurologists see this in situations such as various forms of parkinsonism, including progressive supranuclear palsy. These pure cases are not the concern of Drs. Burns and Anderson in their articles. In straightforward blepharospasm, the eyelids remain shut largely because of contraction of the orbicularis oculi muscle. In some blepharospasm cases, however, apraxia of eyelid opening co-exists with orbicularis oculi over-contraction. This situation is particularly difficult to diagnose definitively without EMG, but might be assumed to exist if the eyelids remain closed even when the orbicularis oculi muscle is markedly weakened with botulinum toxin. Other conditions might contribute to this lack of eyelid opening such as redundant tissue. Thus, the diagnosis of apraxia of eyelid opening in a patient with blepharospasm is often made by assumption, but this might be all that is necessary clinically.

Dr. Burns and Dr. Anderson each have operations that help patients in this circumstance and advocate for their procedures. The key feature of the operations, if apraxia is really the problem, is to help raise the upper eyelid. In Dr. Burns's operation this is a frontalis sling, and in Dr. Anderson's operation this is a ptosis repair or tightening of the levator tendon. The myectomy part of the operation may well be helpful, but largely to more completely alleviate the blepharospasm. I presume both surgical operations work, otherwise the doctors would not advocate for them. Which is better can only be determined for sure by an objective evaluation by an unbiased investigator, who should be masked as to which operation the patient had.

Originally published in the Benign Essential Blepharospasm Research Foundation Newsletter, Volume 24, Number 5, page 4 (2005)

rticle by Burns
Article by Anderson
Article by Pariseau and McCann