Endonasal endoscopic orbital decompression
This is defined as the surgical procedure that permits freeing the orbital contents by endonasal techniques and instrumentation. This surgery is used primarily to treat the orbital consequences of Graves disease and is recommended whenever there is orbital disease, or when there is a severe ocular neuropathy that may or may not be rapidly progressive. The ocular manifestations of this disease are known as dysthyroid orbitopathy and are caused in part by accumulation of T lymphocytes that are sensitized to antigens shared by orbital fibroblasts (Fig. 1). The result of this immunological reaction is that there is orbital congestion with thickening of the extrinsic muscles and of the periorbital fat. This produces exophthalmos and can cause severe consequences that range from cosmetic to vision loss. Dysthyroid orbitopathy seems to follow certain progression that is very independent of the thyroid gland or of its treatment. The severity and extent of the ocular involvement are not proportional to the degree of thyroidal anomalies. Common treatment that is directed towards the thyroidal disease only corrects this and does not control the fundamental process affecting the eye. The acute, initial phase of the orbital involvement typically lasts 6-18 months where there is inflammation and congestion of the orbital content. The increase in volume of the soft tissues raises the intraorbital pressure that leads to displacement of the eye and exophthalmos appears. In severe cases there may be keratosis due to exposure and diplopia with optic neuropathy and vision loss. Corticosteroids may be useful in the initial phase of the flammatory process and improve symptoms, but these return unless the treatment is continued long term.
KeywordsGrave Disease Sphenoid Sinus Middle Turbinate Extrinsic Muscle Orbital Content
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