Surgical Decompression of the Orbit

In 1835 Graves first described the characteristic exophthalmos of thyroid eye disease, and his name has since become synonymous with thyrotoxic ophthalmopathy. Graves disease is relatively common, with a prevalence and incidence of 1% and 0.1%, respectively. Although subtle signs of ophthalmopathy are present in most patients with Graves disease, only 30% have obvious eye findings, and only 5% develop ophthalmopathy severe enough to warrant specific treatment with radiotherapy, immunosuppression, or orbital decompression surgery. Graves disease and Graves ophthalmopathy are more common in females than in males, though males tend to have more severe eye disease. Cigarette smokers have an increased risk of developing Graves disease, an increased risk of developing associated ophthalmopathy, and a progressively increased risk of severe ocular manifestations. While the onset of Graves disease usually occurs when people are in their forties, thyroid optic neuropathy tends to occur in the fifties and sixties, underscoring the importance of careful long-term follow-up of these patients. The ophthalmopathy of Graves disease is usually associated with hyperthyroidism, but it occurs in euthyroid and hypothyroid patients as well. The clinical course of the ophthalmopathy does not directly correlate with the thyroid status, although more than 80% of thyroid patients who develop severe ophthalmopathy do so within 18 months of the detection of the thyroid disease. The early findings of thyroid ophthalmopathy include conjunctival injection, lacrimation, ocular surface irritation, orbital and periorbital swelling, and mild eyelid retraction. Progression of the disease can result in severe orbital congestion, massive enlargement of the extraocular muscles with secondary diplopia, proptosis, compressive optic neuropathy, prominent eyelid retraction, spontaneous subluxation of the globe anterior to the eyelids, and exposure keratopathy. Treatment options for these serious complications of Graves disease include systemic corticosteroids, radiation therapy, and orbital decompression surgery. The role of radiation therapy in the management of Graves ophthalmopathy remains controversial. In 1973, Donaldson et al. first reported results of radiotherapy for Graves ophthalmopathy using a megavoltage linear accelerator. This series and multiple subsequent series have reported favorable results in approximately 60% of patients.