The Dynamic Relationship Between Optic Nerve Intradural Pressure and Intracranial Pressure in Patients with Papilledema

The mechanism of papilledema and visual loss in patients with elevated intracranial pressure (ICP) is unknown, but presumably results from dysfunction of axoplasmic transport, secondary to pressure transmission along the subdural space to the optic nerve. The actual relationship between ICP and the optic nerve sheath pressure (ONSP) has not previously been defined. In this study, catheterization of the optic nerve sheath in four patients (5 eyes) undergoing optic nerve sheath decompression, and one patient receiving exenteration, allowed the determination of ONSP. Simultaneously, the ICP was manipulated and monitored via a lumbar drain.