Bilateral optic disc edema with preserved visual function not related to papilledema.

Bilateral optic disc edema (ODE) with preserved visual function is typically a result of papilledema, but the causes of this finding in the absence of raised intracranial pressure have not been systematically evaluated. The goal of this study was to determine the causes of bilateral ODE with preserved visual function not related to intracranial hypertension to help in developing a differential diagnosis for this finding. We retrospectively reviewed 221 consecutive patients presenting to a tertiary neuro-ophthalmology practice over a period of 2 years. Four patients met the inclusion criteria with a mean age of 53 years (range 43 to 63), 2 patients were men and 2 were women. The final diagnoses were bilateral optic perineuritis secondary to p-ANCA vasculitis, bilateral incipient non-arteritic anterior ischemic optic neuropathy (NAION), hypertensive emergency, and intermediate uveitis. The patient with NAION developed an inferior altitudinal defect 4 months after presentation, but all other patients maintained normal visual function. The ODE resolved in all cases at a mean follow-up of 4.5 months (range 3 to 6 months). Optic disc edema with preserved visual function may not be related to papilledema, and this series indicates that optic perineuritis, incipient NAION, hypertensive emergency, and intermediate uveitis be considered in the differential diagnosis of these cases.