Myelin Oligodendrocyte Glycoprotein Optic Neuritis Presenting With Orbital Apex Syndrome.

A 36-year-old man presented with an acute onset of a right eye monocular altitudinal defect associated with pain on eye movement upon waking up from sleep. His right eye subsequently developed outward deviation and a total loss of vision. Clinical examination of the right eye revealed a visual acuity of no light perception (NLP) with the presence of relative afferent pupillary defect (RAPD) and involvement of cranial nerves II, III, IV, and VI.