Clinical meaning
Papilledema results from transmission of elevated intracranial pressure through the CSF-filled subarachnoid space surrounding the optic nerve to the optic nerve head. Elevated pressure impairs axoplasmic flow within retinal ganglion cell axons at the lamina cribrosa, causing axonal swelling, disc edema, and if sustained, progressive optic atrophy with irreversible vision loss. The three pathological mechanisms include mechanical compression (elevated ICP deforms the lamina cribrosa and impairs axonal transport), vascular insufficiency (compression of capillaries reduces perfusion to the optic nerve head), and excitotoxicity (accumulated glutamate causes retinal ganglion cell apoptosis). Key differentials for optic disc edema include papilledema (elevated ICP), papillitis/optic neuritis (inflammation), anterior ischemic optic neuropathy (vascular), and pseudopapilledema (anatomical variant). The cup-to-disc ratio is assessed on fundoscopy: a ratio of ≤0.3 represents a healthy optic nerve, with progression indicating nerve fiber loss. The nurse performs comprehensive neurological assessment, interprets fundoscopic findings, manages ICP reduction protocols, and coordinates emergency care.