Orbital apex syndrome secondary to optic nerve cysticercosis.

A 22-year-old male presented to us with complaints of sudden painful loss of vision in left eye 10 days ago along with inward deviation of the left eye. Best-corrected visual acuity (BCVA) in right eye was 20/20 and 20/50 in left eye. Left eye showed limitation of abduction, a relative afferent pupillary defect, normal anterior segment with optic disc oedema. Contrast-enhanced MRI of the brain and orbit showed thickening of left optic nerve along with a cystic lesion near the orbital apex with a central iso- to hyperintense spot resembling a scolex. A diagnosis of left orbital apex syndrome secondary to optic nerve cysticercosis was made. Patient was treated with oral albendazole and intravenous corticosteroids for 3 days followed by oral corticosteroids. Ten weeks post-treatment, his BCVA in the left eye improved to 20/20 and colour vision and visual fields improved. Pallor of the left optic disc was noted, and ocular motility improved completely. MRI after treatment showed a decreased thickness of left optic nerve with disappearance of the cystic lesion.