Endocrine Abstracts

Case History: A 30 year old woman presented with the history of swollen painful eyes for 4 weeks while visiting Italy. She had a background of Hashimoto’s Thyroiditis since 2010 and was treated with levothyroxine 100 mcg once daily. She was given a course of oral steroids for 2 weeks and her thyroxine dose was reduced to 25 mcg once daily in Italy. Since then, her orbital swelling began to improve. She was a non-smoker. On examination, she was noted to have bilateral mild proptosis and lid-lag. She had normal visual acuity and visual fields were normal to confrontation. There was no diplopia noted. She had a palpable goitre with bruit.

Investigations: Her thyroid function test showed TSH 0.01, FT3 5.5, FT4 15.9, TPO antibodies 415 and TSH receptor antibodies were 11.4. Her levothyroxine was then stopped. She was referred to Ophthalmology and subsequently had MRI orbits which was normal.

Result and treatment: Her proptosis completely resolved. She subsequently became hypothyroid again (TSH 12.58, FT4 10.9, TSH receptor antibodies 2) and was restarted on levothyroxine.

Discussion: Hashimoto’s and Graves’ diseases represent the main two types of autoimmune thyroid disease. Thyroid-associated eye disease is more common in patients with Graves’ disease and may affect ~25% of these patients. Up to 6% patients with Hashimoto’s may also be affected by thyroid-associated eye disease.⁽¹⁾ However, presentation of Graves’ Ophthalmopathy with subclinical hyperthyroidism in patients with Hashimoto’s Thyroiditis has not been previously reported. There is a strong association of TSH receptor antibodies and Graves eye disease.⁽²⁾ This can be seen in our case as the resolution of Ophthalmopathy correlated with the fall of Thyroid receptor antibodies.

References: 1. Kahaly GJ et al. Thyroid stimulating antibodies are highly prevalent in Hashimoto’s thyroiditis and associated orbitopathy. J Clin Endocrinol Metab. March 10, 2016.

2. Khong JJ, McNab AA, Ebeling PR, Craig JE, Selva D. Pathogenesis of thyroid eye disease: review and update on molecular mechanisms. Br J Ophthalmol. 2016 Jan; 100(1):142–50.