Endocrine Abstracts

A Rare Case of Euthyroid Grave’s Ophthalmopathy with Negative TRAbs titers

Introduction: Graves’ ophthalmopathy (GO; also known as thyroid-associated ophthalmopathy or thyroid eye disease) is clinically evident in 25–50% of patients with Grave’s disease. While the majority of patients experience only mild ocular symptoms, 3–5% of patients with GO suffer from severe disease (2). The spectrum of eye manifestations ranges from lid lag and retraction to proptosis, ophthalmoplegia, conjunctivitis, chemosis, and corneal ulceration, to loss of vision. TSH receptor antibodies (TRAbs) are the pathological hallmark of Graves’ disease, present in nearly all patients with the disease. Euthyroid Graves’ ophthalmopathy (EGO) is a well-recognized clinical entity, but its occurrence in patients with negative TRAbs is a potential source of diagnostic confusion.

Case: We present a case of a 55-year-old male presented to our clinic with 3-months history of impaired vision, left sided exophthalmus and diplopia in the absence of thyroid dysfunction. TRAbs were negative, as measured with a highly sensitive third(-)generation thyrotropin-binding inhibitory immunoglobulin (TBII) ELISA assay. MRI scans of the orbit showed asymmetrical thickening of the all recti muscles, especially inferior recti, with infiltration and no malignant orbital pathology. Graves’ ophthalmopathy (GO) was diagnosed on the basis of the clinical and radiological features, and a good response to treatment with intravenous steroids. By this time, patient had developed positive TRAb as well as thyroid peroxidase antibodies. He responded to treatment with thionamides and remains euthyroid to this day.

Conclusions: This abstract demonstates the unique clinical case where GO developes while being in euthyroid state and seronegative for thyroid autoantibodies. Diagnosing GO is a complex process requiring meticulous review of signs, symptoms, and imaging results while excluding other causes of proptosis such as orbital mass/tumors. Clinicians should be aware of the variable temporal relationship between the clinical expression of thyroid dysfunction and orbital disease in the natural course of Graves’ disease. This case emphasizes the fact that relying on thyroid hormone and autoantibody levels alone is not always adequate for the diagnosis of EGO. Timely diagnosis and initiating proper and adequate treatment would prevent the development of complications and requirement for interventions.