Endocrine Abstracts

Background: TAO is a rare disease, seriously involving 5% of patients with autoimmune thyroid disease. The clinical presentation may be difficult to distinguish from other orbital conditions.

Case 1: A 63-year-old woman was admitted to the Neurology Service for worsening diplopia over the previous six months, with a working diagnosis of myasthenia gravis or multiple sclerosis. The Endocrine Service was consulted because of a long history of Hashimoto’s thyroiditis. The patient was euthyroid on thyroxine replacement. Clinical activity score was 0, but there was restriction in elevation of the right eye. Orbital MRI demonstrated thickening of the right inferior rectus. The diagnosis of TAO was made and the patient received intravenous methylprednisolone with symptomatic improvement.

Case 2: A 48-year-old man with a history of Crohn’s disease, was referred for presumed TAO, with severe diplopia, right retrobulbar pain and exophthalmos. He was euthyroid, with negative thyroid antibodies. Orbital MRI demonstrated thickening of all extraocular muscles of the right eye. A diagnosis of orbital myositis was made. The patient received 1.5g intravenous methylprednisolone with marked improvement, but a month later presented with a red left eye and diplopia. Orbital CT demonstrated thickening of the superior oblique and the medial rectus. The patient again received intravenous methylprednisolone with complete remission and remains asymptomatic from his orbital and bowel disease one year later.

Case 3: A 45-year-old woman was referred to the Endocrine Service with right sided ptosis, for presumed TAO. She was euthyroid, with negative thyroid antibodies. Eye exam was normal except for right-sided ptosis. Orbital MRI was normal. On further questioning, the patient admitted having had botulinum toxin injections on the forehead and right brow a week before.

Conclusion: The differential diagnosis and management of orbitopathy often relies on the Endocrinologist and spans the spectrum of divergent medical specialties.