THU668 Euthyroid Graves’ Ophthalmopathy: Case Series

Abstract Disclosure: S.S. Alfadl: None. A.A. Asiri: None. A.A. Jammah: None. O. Alsagheir: None. Introduction: Graves’ ophthalmopathy is an autoimmune disorder that affects the eyes, characterized by swelling, proptosis, lid lag, inflammation and eyelid retraction. A significant proportion of cases are associated with thyrotoxicosis and positive serum TSH receptor antibody tests. Case Description: We present a case series of euthyroid Graves’ ophthalmopathy in patients with a negative TSH receptor antibody. The first case is of a 37-year-old lady who was recently diagnosed with idiopathic intracranial hypertension due to history of recurrent headaches and was found on CT brain to have an incidental empty sella syndrome and findings highly suggestive of thyroid associated orbitopathy. A dedicated MRI orbit showed bilateral mild proptosis with bilateral medial and inferior recti thickening, sparing the tendinous insertion. The involved extraocular muscles show mild peripheral high T2 signals and minimal enhancement on post gadolinium images. The enlarged extraocular muscle demonstrates diffusion restriction with low Apparent Diffusion Coefficient (ADC) value. Clinically, the patient did not exhibit any symptoms of hyperthyroidism or hypothyroidism. She did not notice any changes in her eyes’ appearance, nor any changes in vision or double vision. On examination, she had mild proptosis, no restriction of extraocular movement or provoked double vision. Consequently, she was referred to Ophthalmology for further management. Investigations included a pituitary panel which did not reveal any abnormalities and a thyroid panel which revealed that she was biochemically euthyroid with a negative TSH receptor antibody test. The second case is of a 24-year-old male who is medically free and initially visited the ophthalmology clinic complaining of double vision, without any additional ophthalmic complaints. He was subsequently referred to our care to rule out thyroid eye disease. Clinically, the patient had no indications of thyroid dysfunction. Upon examination, he exhibited severe right eye proptosis with dystopia and early left eye proptosis. CT orbit showed swelling of the right-sided superior rectus, medial rectus, lateral rectus and left-sided superior rectus muscles. The left-sided superior rectus muscle was abutting the optic nerve. Nevertheless, all tendons were spared. Biochemically, he was euthyroid with unremarkable laboratory results. Conclusion: These findings provide insight into the clinical presentation of euthyroid Graves’ ophthalmopathy in patients without thyrotoxicosis or detectable circulating levels of TSH receptor antibodies. Thus, suggesting that thyroid ophthalmopathy might present earlier than Graves’ disease and even earlier than the presence of TSH receptor antibodies. We conclude that a high index of suspicion and proper follow up is recommended in similar patients for the development of Graves’s disease. Presentation: Thursday, June 15, 2023