Endoscopic Orbital Decompression

Endoscopic Orbital Decompression/Graves Orbitopathy
Graves’ disease is an autoimmune disorder that can affect the thyroid gland, as well as the orbit.
In Graves’ disease, autoantibodies to thyrotropin receptors in the thyroid gland result in over
stimulation of the gland and subsequent hyperthyroidism.
Orbital manifestations then result from pronounced inflammation, migration of T-cells and
deposition of glycosaminoglycans. This in turn, can lead to enlargement of orbital fat content and
extraocular muscles, resulting in increased orbital pressure, proptosis, and possible optic nerve
compression.

Symptoms of this Graves’ orbitopathy may include tearing, proptosis, diplopia/double vision,
and visual loss. Graves’ disease can also be classified as either acute or chronic. Active
inflammation for 6-18 months marks the acute phase; symptoms are initially treated with local
conservative measures such as taping and lubrication. In severe cases, systemic steroids or
radiation may be considered. The chronic phase involves severe fibrosis of orbital contents and
may respond to surgical management. Indications for endoscopic orbital decompression include
visual changes, as well as severe proptosis resulting in exposure keratitis or cosmetic deformity.
Certain patients may be candidates for endoscopic orbital decompression. This is performed
through the nose using endoscopes and specialized instrumentation. Once the sinus cavities are
meticulously opened, the medial orbital wall and part of the orbital floor are removed, after
which the soft tissue envelope of the orbit, the periorbita, is incised. This allows for prolapse of
orbital contents into the sinus cavities, thus decompressing the orbit.

Success rates of such procedures are quoted as ranging from 22-89%. Ocular recession as a result
of orbital decompression averages approximately 3.5mm. Complications of this technique
include diplopia, bleeding, epiphora/tearing, CSF leak, and blindness. Of particular concern is
chronic sinusitis, and specifically frontal sinusitis, occurring in the presence of prolapsed orbital
contents scarring to the middle turbinate. Post-operative debridements are essential to help
reduce this risk.