Optic Nerve Decompression
John Lee, MD
Optic nerve decompression is a surgical procedure aimed at removing a portion of the bony canal (tunnel) which houses the optic nerve (See Figure: arrows point to optic canals). The optic nerve is the “nerve of vision” and extends from the brain, through your skull, and into your eye. A portion of the optic nerve is enclosed in a rigid, bony tunnel as it exits the skull. Because of this, any condition which causes swelling or compression of the optic nerve at this location may lead to a loss of vision or blindness because there is no room or space for the nerve to expand. The goal of optic nerve decompression is to remove a portion of the bony optic canal, thereby relieving some of the pressure on the optic nerve. This procedure is done with the use of endoscopes (small rigid telescopes), allowing your surgeon to go through the nose and sinuses to perform this delicate surgery without any cuts to the face. In the following sections, we will review the indications, risks and benefits of endoscopic optic nerve decompression.
The reasons for optic nerve decompression usually involve any condition which is threatening or causing visual loss because of significant pressure along the optic nerve near the optic canal. This can occur because of tumors (growths) within the eye which directly exert pressure on the nerve or also because of an overgrowth of bone (fibro-osseous lesions) which may narrow the optic canal. In the cases of head injury or trauma, the optic nerve may be compressed either from a direct bone injury at the canal or because of swelling (inflammation) of the nerve within the canal itself. In either case, surgery is only indicated if your surgeon believes that relieving the pressure of the optic nerve at the canal will help restore or prevent a deterioration of your vision.
Endoscopic optic nerve decompression is a surgical procedure which is performed under a general anesthetic (going all the way to sleep). Going through your nose, your surgeon will first perform endoscopic sinus surgery and open the sinuses directly beside the eye. In particular, the ethmoid and sphenoid sinuses are directly adjacent to the optic nerve and canal. Once this is complete, a portion of the bone overlying the optic canal is removed. This effectively enlarges the space of the bony canal, thereby “decompressing” the optic nerve. At the end of surgery, there is usually no packing in the nose. You may be kept in hospital for close observation for a few days.
Endoscopic optic nerve decompression involves operating both within the eye and in the sinuses. Therefore, there are known risks of this surgery. This includes, but is not limited to, the following: loss of vision, double vision, inadequate decompression of the optic nerve, bleeding around the eye, carotid artery injury, leakage of brain fluid (CSF), meningitis, nasal bleeding, infection of the eye, and sinusitis.
By removing a portion of the bony optic canal, endoscopic optic nerve decompression may decrease the pressure along the optic nerve. This may prevent the deterioration of vision or restore vision in certain cases.
Endoscopic optic nerve decompression is a delicate procedure which may be useful in select cases of swelling or compression of the optic nerve. Speak with your surgeon to see if you are a candidate for this type of surgery
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