Cyclic vertical deviation.

A 34-year-old Caucasian woman underwent craniofacial surgery for fronto-orbital fibrous dysplasia. She developed vertical diplopia for 10 months after surgery, which then disappeared for 1 month. The deviation returned with a circadian pattern, 24 hours of hypertropia and exotropia with diplopia alternating with 24 hours of straight eyes and fusion. Three months after the onset of this pattern, surgery was performed, resulting in straight eye position and fusion daily. The similarities to cyclic esotropia are discussed. The etiology of circadian strabismus remains unknown.