Rapidly progressive vision loss due to fulminant idiopathic intracranial hypertension: a diagnostic and management dilemma.

A 44-year-old obese woman presented with decrease in vision in the right eye (RE) for 3 days. She reported a simultaneous onset of holocranial headache that worsened on bending forward. She denied eye pain, pain on eye movements, and other ocular or neurological complaints. On examination, her distance best-corrected visual acuity was counting fingers at 1 m in the RE and 20/20 in the left eye (LE). Colour vision was subnormal in both eyes (BE). There was grade II relative afferent pupillary defect in the RE. Fundus examination showed disc oedema in BE . Visual fields in the LE showed central scotoma extending nasally. A provisional diagnosis of papillitis was considered. However, contrast-enhanced MRI of the brain and orbits showed evidence of elevated intracranial pressure. Cerebrospinal fluid (CSF) opening pressure was 42 cm HO while rest of the CSF analysis was normal. Diagnosis was revised to fulminant idiopathic intracranial hypertension. Management with medical therapy and urgent thecoperiteoneal shunt improved visual function in BE.