The Optic Nerve Compartment Syndrome in Cryptococcus-Induced Visual Loss.

Visual loss in cryptococcal meningitis has been postulated to be due to papilloedema and/or optic neuritis. A 28-year-old human immunodeficiency virus (HIV)-positive female presented with visual loss, swollen optic discs, and elevated intracranial pressure due to cryptococcal meningitis. Computerised tomographic cisternography and T2-weighted magnetic resonance imaging showed occlusion of the peri-optic subarachnoid space and its reopening after serial lumbar punctures. Presumably lowering of the intracranial pressure resulted in equalisation of pressure across the pressure gradient created by the fungal block. This case supports a third mechanism of visual loss in cryptococcal meningitis, namely, an optic nerve compartment syndrome, that seems more plausible as the principal mechanism.