Major complications during endoscopic sinus surgery include injury to the orbit, skull base and blood vessels. There complications are, however, rare. Patients have to be informed of these complications so that they are aware of the risks involved and are able to make an informed decision before signing the consent for the surgery. Orbital Complications:The sinuses are closely related to the orbit (eye socket), which contains the eye globe. The bony partition between the eye and the sinuses is extremely thin. It is called lamina papyrecea, lamina meaning wall and papyrecea means like paper. So, it is literally paper thin. Extreme caution has to be exercised during the surgery to identify this wall and ensure that it is not breached. Unfortunately, in the presence of disease, it may be difficult to identify. The inexperienced and novice surgeons may be a factor. Depending on the extent of the breach, the following orbital complications may result:
- Peri-orbital oedema: mild swelling around the eye particularly over the eyelids may result from a minor breach of the lamina. The vision and eye movements remain normal. The swelling subsides over a few days.
- Orbital hematoma: This is a serious complication where not only the lamina has been breached but there has been internal injury to the orbital fat and blood vessels with in. As a result of bleeding within the orbit, the pressure within the orbit rises, the eye globe protrudes outwards (proptosis) and with increasing pressure the blood supply to the optic nerve may be compromised resulting in blindness.
- Extra-ocular muscle injury: The movement of the eye globe are controlled by six muscles called the extra-ocular muscles. One of the muscles, the medial rectus, is very close to the lamina. Injury to this muscle, when the orbit is breached, may result in a partial or complete tear. This may lead to temporary or permanent double vision (diplopia).
- Optic Nerve Injury: This may result indirectly from orbital hematoma or due to a direct injury. This is a serious complication often resulting in permanent visual loss.