Diplopia in a patient with Hashimoto's thyroiditis

BACKGROUND A case report of Hashimoto's thyroiditis-associated ophthalmopathy that masqueraded as double elevator palsy in 1 eye. CASE PRESENTATION A 54-year-old woman presented to our strabismus clinic with diplopia for 1 year. She was diagnosed with double elevator palsy in the left eye. The forced duction test yielded positive findings for the inferior rectus of the left eye; hence, computed tomography of the orbit and thyroid-associated blood tests were performed; surprisingly, the thyroid function test results were consistent with hypothyroidism and the antibody results such as antithyroglobulin and antithyroid peroxidase were markedly elevated, and the patient was diagnosed with Hashimoto's thyroiditis and treated with corticosteroids. Unfortunately, her diplopia was not relieved with medical management. Subsequently, a 9-mm left inferior rectus recession was performed. CONCLUSION Clinicians should be aware of the atypical signs of Hashimoto's thyroiditis for its proper diagnosis and management.