We encountered a rare case of optic neuritis that developed in a sphenoid sinusitis. This case has not been reported at any of the Korean Ophthalmological Society meetings.

A 12-year-old boy with swollen optic disc was diagnosed with optic neuritis secondary to sphenoid sinusitis, through orbit MRI (magnetic resonance imaging) and paranasal sinus CT (computed tomography). We observed the recovery of visual acuity and the improvement of papilledema after treatment. In the initial examination, the BCVA (best-corrected visual acuity) of the right eye was only hand movement. Papilledema was detected by ophthalmoscopy. Orbit MRI and paranasal sinus CT were then performed, which revealed that sphenoid sinusitis had invaded the right optic nerve. Treatment included the use of antibiotics, systemic steroid therapy, and endoscopic sinus surgery. One month after treatment, the BCVA of the right eye was 1.0 and the papilla of right eye had a normal ophthalmoscopic finding.

Sphenoid sinusitis can be a cause of optic neuritis. The treatment of optic neuritis caused by paranasal sinusitis must include antibiotics use or endoscopic sinus surgery to remove the sinus inflammation as well as high dose steroid therapy.