The Marcus Gunn phenomenon. A review of 71 cases.

We have reviewed the clinical findings, natural course, pathologic observations, and management of 71 patients with the Marcus Gunn phenomenon. We found individuals with this syndrome to have a significant incidence of amblyopia (59%), double elevator palsy (25%), anisometropia (25%), and superior rectus muscle palsy (23%). Long-term follow-up did not reveal a case that improved with age. In most patients requiring surgery, we recommend a unilateral levator excision on the affected side plus a bilateral frontalis suspension.