Atypical vertical retraction syndrome: a case study.

A case of unilateral retraction of the eyeball in downward gaze as well as downshoot with the retraction when an outward horizontal movement of the contralateral eye was attempted has been introduced. The case has an exotropia with inability to adduct involved eye. The face turned to the left to minimize diplopia in the primary position. During the retraction, the lid widened slightly. An analyses by electrooculography and electromyography suggested that there was an abnormal neural connection between the vertical recti of the involved eye and the contralateral lateral rectus muscle. Co-contraction of vertical recti and loss of the reciprocal innervation were seen at the involved eye. Surgical treatment for exotropia, and total transplantation of vertical recti to the insertion of the involved medial rectus resulted in a slight reduction of the exotropia with the face straight, but not in the retraction as well as adduction and elevation of the involved eye. Based on the results, a central mechanism to produce above abnormality was described.