The twists and turns of optic disk swelling in a teenager.

A 17-year-old girl developed headaches, transient visual obscuration, pulsatile tinnitus, and hearing loss during an episode of pneumonia. Neuro-ophthalmologic examination disclosed severe bilateral optic disk swelling and macular exudate in the right eye. Lumbar puncture showed an opening pressure of 55 cm H2O without neurochemical abnormalities. Subsequent magnetic resonance imaging showed no mass lesion or signs of venous sinus thrombosis, confirming the diagnosis of idiopathic intracranial hypertension. Following the lumbar puncture, the papilledema resolved but visual acuity decreased to 20/40 in the right eye despite normal color vision. Perimetric signs of psychogenic visual loss developed. This case underscores that hyperacute papilledema can simulate bilateral optic neuritis and illustrates the importance of color vision testing in distinguishing macular visual loss from optic neuropathy. It also illustrates the confounding effect of psychogenic visual loss in judging the clinical course of idiopathic intracranial hypertension.