[Optic nerve sonography - the non-invasive evaluation of intracranial pressure].

Intracranial hypertension is a common life-threatening syndrome caused by a variety of neurological and non-neurological diseases. Enlargement of the optic nerve sheath has been described in patients with raised intracranial pressure (ICP). Optic nerve sonography offers rapid bedside assessment of the optic nerve sheath diameter (ONSD) and has recently been introduced for the noninvasive detection of raised ICP. This study explains the pathophysiology of optic nerve sheath enlargement as a result of intracranial hypertension, describes the technique and clinical use of optic nerve sonography.