Variable synergistic divergence

Abstract

Purpose: To report a patient with congenital fibrosis of the extraocular muscles showing either synergistic divergence or adduction.

Case report: A 7-year-old girl presented with complaints of abnormal eye movement since early childhood. A detailed ophthalmologic examination was performed. On ophthalmologic evaluation, her corrected visual acuities were 20/50 OU. She had 12 prism diopters of exotropia at distance and near in the primary position. During attempted right gaze, OU abducted. During attempted left gaze, the right eye adducted or abducted. Upgaze and downgaze were limited. Levator function was evaluated at 0 mm with a marginal reflex distance of -1 in OU. On thin-section brain stem magnetic resonance imaging, the left abducens nerve was absent, and the right and left oculomotor nerves were severely hypoplastic. The oculomotor nerve was smaller than the acoustic nerve was, and this was interpreted as hypoplasia according to a previous method (Kim and Hwang, Ophthalmology 2005;112:728-32). The medial and superior recti of OU were atrophic.

Conclusions: A patient with congenital fibrosis of the extraocular muscles may show alternatively either synergistic divergence or adduction, which has not been documented before.