Clinical Characteristics of Patients with Euthyroid Thyroid-associated Ophthalmopathy

Abstract

Purpose: To compare clinical features between thyroid-associated ophthalmopathy (TAO) patients with hyperthyroidism and euthyroidism.Methods: Between September 2015 and January 2021, we enrolled 96 TAO patients with euthyroidism (n = 16) or hyperthyroidism (n = 80). We recorded the age, sex, smoking status, presence of hypertension and diabetes, total follow-up period, unilateral involvement, eyelid edema, lid lag and retraction, clinical activity score (CAS), modified NOSPECS score, exophthalmometry, Hess test, area of extraocular muscles on orbital computed tomography (CT), treatment with systemic and subconjunctival steroids and radiotherapy, and serum levels of free thyroxine, thyroid-stimulating hormone (TSH), anti-thyroglobulin antibody (anti-Tg Ab), anti-thyroid peroxidase antibody (anti-TPO Ab), TSH receptor antibody (TSHR Ab), and thyroid stimulating antibody.Results: Unilateral involvement was significantly more common in the euthyroid group, while conjunctival injection, CAS, extraocular muscle movement restriction within 10° on the Hess chart, maximum cross-sectional area of the inferior rectus on orbital CT, and treatment with intravenous high-dose steroid were significantly more common in the hyperthyroid group. Furthermore, the modified NOSPECS score and levels of free thyroxine, anti-Tg Ab, anti-TPO Ab, and TSHR Ab were significantly higher in the hyperthyroid than euthyroid group.Conclusions: Compared to hyperthyroid TAO patients, those with euthyroid TAO were more likely to have unilateral involvement. They also had lower clinical activity and severity, milder enlargement of extraocular muscles (EOMs), and lower rates of EOM movement restriction and treatment with intravenous high-dose steroid. Euthyroid TAO patients had lower levels of free thyroxine, anti-Tg Ab, anti-TPO Ab, and TSHR Ab compared to hyperthyroid TAO patients.