We report a case of ophthalmic artery occlusion with third nerve paresis in the left eye due to acute occlusion of the left ICA.

A 37-year-old man visited our emergency room with "black out" in the left eye, headache, and nausea. The corrected visual acuity was 20/25 in the right eye, and hand motion in the left eye. In the left eye, a relative afferent papillary defect was noted, with an intraocular pressure of six mmHg. Twenty prisms of exotropia in the primary position was observed, and ocular motor examination revealed limitations of supraduction, infraduction, and adduction in the left eye, suggesting third nerve palsy of the left eye. Fundus examination revealed a pale retina in the macula of the left eye. Brain MRI demonstrated multifocal faint low densities in the left caudate nucleus as well as the frontal and parietal lobes. CT angiography and four-vessel angiography demonstrated complete occlusion in the proximal part of the left internal carotid artery ICA.

After five months the corrected visual acuity of the left eye improved to 20/200. The 20 prism diopters of exotropia persisted, and ocular motor examination revealed only a mild limitation of adduction in the left eye.