Optic Nerve Decompression

Optic nerve sheath decompression, more commonly known as optic nerve sheath fenestration (ONSF), is a surgical procedure performed to decompress the optic nerves and relieve vision-threatening papilledema in the setting of elevated intracranial pressure (ICP). Performance of this procedure is generally in cases of pseudotumor cerebri syndrome (PTC), where patients are rapidly losing vision from significantly elevated ICP, or in cases of progressive vision loss in patients who do not respond to medical therapy or are non-adherent with therapy. The exact mechanism by which fenestration relieves papilledema is not entirely understood at this time; however, both decompression of the perioptic subarachnoid space with filtration of cerebrospinal fluid (CSF) out of the subarachnoid space through the dural opening as well as scarring of the surgical site that prevents further accumulation of CSF are felt to be contributing factors. Optic nerve sheath decompression does not treat the source of the elevated ICP itself, but the procedure does diminish the associated visual sequelae.