Orbital decompression surgery is a form of treatment that focuses on enlarging the space bounded by the four walls of bone that make up each eye socket. The word “orbital” refers to the anatomic term that describes the space enclosed by the borders of the eye socket. Enlargement of this space may help to relieve the pressure that compresses the optic nerves, traps the extraocular muscles, and forces the eyeballs to protrude outward. Most of the operations performed to treat severe thyroid eye disease involve the removal of portions of the one or more of the four walls of bone that make up each eye socket. This approach serves to open up spaces along the sides of the eye sockets, allowing the contents to push outward to relieve pressure exerted on the eyeballs, optic nerves, and extraocular muscles. A different operation focuses on the removal of the fatty tissue present in each eye socket. This maneuver helps to open up more free space to accommodate the swollen portions of the extraocular muscles, decompressing the eye sockets without changing their underlying structure.
Orbital decompression surgery may be considered as primary therapy when there is a need to urgently relieve pressure in the eye sockets to prevent loss of sight due to compression of the optic nerves. It may also be considered as primary therapy in cases where severe protrusion of the eyeballs may make it difficult or impossible for the eyelids to close to protect the corneas. Scarring that may develop in this situation as a result of exposure keratitis may impair vision. Orbital decompression surgery may be used to treat of cases of severe thyroid eye disease that have failed to respond to immunosuppressive therapy or orbital radiation therapy. It may also be used for cosmetic purposes to minimize the disfiguring effects of severe proptosis.