Multidisciplinary management approach needed for thyroid eye disease
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Thyroid eye disease was first described by Robert James Graves, FRCS, an Irish surgeon who recognized the association of hyperthyroidism with exophthalmos in 1835. Even today, many use Graves’ ophthalmopathy when discussing this disease.
The eye and periocular findings are most commonly associated with hyperthyroidism but can also be associated with hypothyroidism, Hashimoto’s thyroiditis or normal thyroid function. Women are five to six times more likely to develop thyroid eye disease (TED), and it most commonly presents between the ages of 30 and 50 years. Significant risk factors for progression include smoking and diabetes.
As a resident in ophthalmology working with our cornea, oculoplastic service and the endocrinology department at the University of Minnesota 45 years ago, I never understood why thyroid disease affected the periocular structures. Today, we know that TED is an autoimmune disease. Autoantibodies targeting the thyroid gland also target fibroblasts and fat cells in the orbit, resulting in cellular proliferation and enlargement, which along with inflammatory cell infiltration, results in enlargement of the ocular muscles and periocular fat. Over time, venous and lymphatic obstruction can also occur.
There is only one place the eye can go, and that is outward in proptosis. The first muscle affected is usually the inferior rectus, so restricted upgaze is an early finding with secondary diplopia. TED has seven stages of increasing severity. The early stages are characterized by progressive proptosis and associated lid lag and diplopia. In the later stages, exposure keratopathy is a critical issue requiring treatment, and the most dreaded complication is visual loss from optic nerve damage, likely caused by optic nerve stretching and compression.
Management requires a team approach including endocrinology, diagnostic and therapeutic radiology, otolaryngology and an ophthalmology service with expertise in cornea, strabismus, oculoplastic and orbital surgery. The first challenge is to diagnose and treat the thyroid disease. Medical therapy today for TED includes the newly approved Tepezza (teprotumumab, Horizon Therapeutics). Data suggest that as many as 80% of patients will respond to Tepezza with reduced proptosis, diplopia and corneal exposure. It is an expensive therapy at $350,000 and requires a 24-week course, and it may need to be repeated 1 or more years later. However, for many patients with severe TED, Tepezza is a miracle drug.
Other systemic therapies include steroids, usually beginning with a course of intravenous methylprednisolone often followed by a maintenance dose of oral steroids. When chronic steroid therapy is required, steroid-sparing agents such as methotrexate, cyclosporine, azathioprine or mycophenolate are usually added. Oral selenium and statins have helped some patients.
The ophthalmologist’s first charge is to manage the diplopia and protect the cornea. Spectacles with prism and frequent topical lubricants, preferably non-preserved, with a lubricating ointment and lid taping or moisture chamber goggles at night can be helpful. Plastic surgery to lower the upper eyelid using marginal myotomy, Müller’s muscle resection and/or lateral cantholysis is often employed. Orbital decompression can be required to prevent optic nerve damage in advanced cases. Surgical management of advanced cases requires the combined skills of an oculoplastic surgeon, an otolaryngologist and occasionally even a neurosurgeon.
A multidisciplinary management approach along with an experienced endocrinologist brings all but the mildest TED cases to major institutions.
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