Surgical Treatment for Idiopathic Intracranial Hypertension: Optic Nerve Sheath Fenestration

Optic nerve sheath fenestration (ONSF) is one of the surgical treatments for visual preservation and rescue in idiopathic intracranial hypertension (IIH). A variety of ONSF surgical techniques exist but all approaches include incising and releasing the dura mater and associated arachnoid surrounding the optic nerve axons. The optic nerves are subject to the intracranial cerebral spinal fluid pressure both within the central intracranial space and within each orbit. Cerebral spinal fluid (CSF) diversion procedures or unilateral ONSF may impact the entire visual system but the benefit may be limited to the individual space drained. ONSF should be considered when axonal function is acutely compromised with the potential for recovery of dying and uninjured axonal fibers. ONSF is a complex, retrobular orbital surgery and should be performed by orbital surgical experts in a minimally invasive, non-traumatic fashion to lessen any further injury to the nerve. Aggressive, early surgical intervention must be considered n patients presenting with significant vision loss.