SAT-358 Not a Stroke: A Case of Sight Threatening Thyroid Eye Disease With Delayed Diagnosis

Abstract Disclosure: M. Dillon: None. G. Gupta: None. V. Kantorovich: None. Introduction: Thyroid eye disease (TED) is common in autoimmune thyroid disease. It’s usually diagnosed clinically and treated non-urgently. However, some patients are difficult to diagnose due to appearance and lack of awareness. This can hinder urgent treatment in sight threatening severity, especially if socio-economic factors will cause further delays. Case: An 83-year-old female, with past medical history of atrial fibrillation, heart failure with preserved ejection fraction, chronic kidney disease, multiple myeloma, and Graves’ disease, stopped methimazole due to thyroid stimulating hormone elevation to 61 mIU/L. Shortly afterwards, she presented with three weeks of sudden non-traumatic diplopia. Her progressive symptoms worsened when looking to the left. Ophthalmology gave a short oral steroid course with no effect. After repeat evaluation, she was sent to the hospital for stroke evaluation. Physical exam revealed a new left abducens palsy and mild proptosis noticeable if her glasses were removed. Hospitalists had low suspicion for TED as no thyroid treatment was on her medication list. MRI brain was negative for acute infarct. MRI orbit was delayed by several days, but did show fusiform enlargement of multiple bilateral extraocular muscles with T2 hyperintensity, significant bilateral proptosis, and infraorbital fat deposition with mild infiltration. As her TED was sight threatening, the patient started IV methylprednisolone pulse therapy. She was discharged while insurance prior authorization and determination of teprotumumab eligibility was pending. Follow up was complicated there was no registered Tepezza provider in her healthcare network. Discussion: Classically, Graves’ eye disease is clinically diagnosed based on proptosis, conjunctival inflammation and periorbital edema. Diagnosis can be difficult if parts of the triad are missing or less obvious. Additionally, TED may not be in a provider’s differential for patients not on active treatment or with antibodies but no clinical thyroid disease. Therefore, it is important to maintain high clinical suspicion. A non-contrast CT scan or MRI of the orbits can be obtained for patients with ambiguous clinical exams. As in our patient, significant proptosis may be present when exophthalmos is not obvious. Patients with severe soft tissue involvement, severe corneal exposure or optic nerve compression need immediate treatment due to sight threatening potential. The two available treatments are IV methylprednisolone pulse therapy or the insulin-like growth factor monoclonal antibody Teprotumumab. Unfortunately, there can be barriers to accessing the antibody treatment. These can include a need for follow-up with a hard-to-find thyroid eye disease specialist registered with the company, lack of insurance coverage, treatment expense, and a lack of infusion center nurses trained to assess hearing. Presentation: Saturday, July 12, 2025