Non-arteritic anterior ischemic optic neuropathy : A potenti
Patients may lose vision in idiopathic intracranial hypertension from worsening papilledema and optic nerve dysfunction. Acute vision loss may also occur in this context from anterior ischemic optic neuropathy. A case of a 29-year-old woman with bilateral moderate papilledema from idiopathic intracranial hypertension who experienced a sudden loss of vision in the superior part of the visual field of her right eye. She was found to have a new relative afferent pupillary defect and a stable superior altitudinal defect with optic disc pallor. Papilledema often creates crowding of the optic nerve head and places patients at risk for anterior ischemic optic neuropathy.

Non-arteritic anterior ischemic optic neuropathy (NAION) is the most common acute optic neuropathy in older individuals and is associated with systemic conditions such as hypertension, diabetes mellitus, and obstructive sleep apnea. Essentially all individuals who develop NAION have a so-called disc-at-risk, which is an optic nerve with a small or absent physiologic cup.1 Papilledema often results in the obscuration of the physiologic cup in moderate to severe cases and causes a disc-at-risk. This creates the necessary substrate for NAION, which has previously been reported in IIH. This patient had a previously documented disc-at-risk on a routine optometry examination one year prior and the papilledema further increased the crowding at the optic nerve head. She also had several documented elevated blood pressures, which also likely predisposed her to this event.
The diagnosis of NAION was supported by the sudden vision loss, new RAPD, and altitudinal defect, which is the characteristic field defect in this condition. This defect also persisted despite the resolution of papilledema in both eyes. It is important to recognize the diagnosis of ischemic optic neuropathy since the new visual field deficit may have been attributed to worsening papilledema or increasing intracranial pressure resulting in consideration of surgical interventions such as a shunt.
In summary, NAION should be considered as a cause of vision loss in patients with papilledema especially when the vision change is sudden. This must be differentiated from visual field defects from worsening papilledema, which may require surgical intervention.
1 share