What does this treatment involve?
Orbital decompression surgery is performed on patients whose eyes (one or both) are bulging out towards the eyeball (exophthalmos).
Patients with exophthalmos usually experience an increase in pressure in the space behind the eyeball (orbital cavity) which compresses the space including the fat content, muscles, nerves and blood vessels.
This surgical procedure increases the space of the orbital cavity, which is surrouded by four bone walls and it repositions the eyeball and reduces the pressure in the orbital cavity.
When is this treatment indicated?
It is indicated for patients with exophthalmos and thyroid orbitopathy. Once operated on for orbital decompression, patients with anterior movement of the eye might find see an aesthetic improvement, since after the procedure the eye moves into the orbital cavity again. They may also see a functional improvement.
In patients with thyroid orbitopathy, this technique is used to improve the eyesight of patients with optical neuropathy (damage to the optic nerve as a result of an increase in the volume of muscles leading to optic nerve compression). It also alleviates the cornea as these patients usually find it hard to close their eyes.
How is it performed?
The procedure involves widening the orbital space and is performed on the bone walls thereof. It is done by removing a part of the bone wall, i.e., by creating connections between the orbital cavity and the contiguous spaces (the adjacent sinuses), which makes the cavity larger.
As part of our specialism, this procedure can be performed on the lateral wall, medial wall, lower wall or even a combination thereof. The lateral approach is perfomed by making an incision in the external canthus of the eye.
On the inside, a transconjunctival incision is made (rear side of the eyelid) so that the scar is not visible. In the medial side, a transcarancular incision or incision across the nose is made (the approach most commonly used by otorhinolaryngologists).
Results
Decompression of the medial and inferomedial wall is advised for patients with serious posterior optical neuropathy, above all those who have thyroid orbitopathy with an increase in the volume of their muscle belly at orbital apex level.
Lateral decompression causes less strabismus and greater reduction of exophthalmos, above all in cases where the surgical technique used makes a wide and deep connection in the lateral wall. In serious cases, the approaches can be combined.
Possible risks
The most common postoperative complication is double vision (diplopia), haematoma and oedema of the eyelids and conjunctiva which goes away after a few days.
The least common but most feared postoperative compication is orbital haemorrhaging, which could potentially cause a loss of visual acuity and even blindness. Despite the fact that the orbit contents make contact with the paranasal cavities, infections are very uncommon.