[Indications and technique of optic nerve sheath fenestration].

An optic nerve sheath fenestration is indicated when papilloedema leads to progressive visual loss despite previous, conservative measures and when no cause of increased intracranial pressure can be indentified and eliminated. This rather rare constellation usually occurs in idiopathic intracranial hypertension. The procedure is performed via a medial transconjunctival orbitotomy. If headaches and neurologic symptoms other than visual deterioration prevail, the placement of a ventricular shunt is preferred. This review covers the symptoms of idiopathic intracranial hypertension and optic nerve sheath fenestration with its technical aspects and results.