Operation on the optic nerve. Access through the sinus cavity makes this possible.
The sinus cavities and eye sockets are anatomically extremely close together and compacted. The proximity of structures can be taken advantage of to operate on the optic nerve, for instance. Before this anatomical structure, also called the nervus opticus, enters the eye socket, it passes through a bony canal called the optic nerve channel that doctors refer to as the canalis opticus. The microsurgical or endoscopic method makes use of the fact that the wall of the channel is formed by the bones of the sphenoid sinus and is therefore part of the paranasal sinuses.
Some of the sphenoid sinus bone may be removed in order to reach the optic nerve during surgery without having to resort to external surgical access. In this way we create access and can directly operate on the optic nerve. These procedures can help the patient considerably if:
- The optic nerve has come under pressure and we want to use decompression of the optic nerve to relieve this.
- A head injury has resulted in blindness, which can potentially be relieved by decompression of the optic nerve.
- The patient is suffering from progressive visual impairment, as the optic nerve is becoming increasingly crushed by a slowly growing tumour. This can also place it under severe pressure and continuously restrict its function.