Monocular nystagmus with sectoral optic nerve hypoplasia in a patient with septo-optic dysplasia.

This case depicts an unusual presentation of septo-optic dysplasia. A four-year-old female presented with monocular nystagmus and temporal optic disc pallor in her left eye. Despite a normal sized optic nerve head, magnetic resonance imaging (MRI) showed a hypoplastic intraorbital and intracranial left optic nerve in the absence of a septum pellucidum. She was subsequently diagnosed with septo-optic dysplasia with sectoral optic nerve head hypoplasia.