Total thyroidectomy (Tx) versus thionamides (antithyroid drugs) in patients with moderate-to-severe Graves' ophthalmopathy - a 1-year follow-up: study protocol for a randomized controlled trial

Graves' disease (GD) is characterized by thyrotoxicosis and goiter and arises through circulating autoantibodies that bind to, and stimulate, the thyroid hormone receptor (TSHR). A temporal relation between the onset of hyperthyroidism and the onset of ophthalmopathy, a common extrathyroidal manifestation, has been demonstrated. Graves' ophthalmopathy (GO) is typically characterized by an inflammation and expansion of the extraocular muscles and an increase in retroorbital fat. There are currently three forms of therapies offered for hyperthyroidism caused by Graves' disease: antithyroid drugs (ATD) (thionamides), radioiodine ablation (RAI) and thyroidectomy (Tx). To date, there is no clear recommendation on the treatment of Graves' disease and GO, mainly due to the individuality of the disease in each patient. The aim of the study is to examine the difference in the outcome of GO in patients with moderate-to-severe GO who receive Tx versus further ATD after suffering their first relapse of GO, or in which GO stays the same following the initial decrease in ATD therapy after 6 months.

This prospective randomized clinical trial with observer-blinded analysis will analyze 60 patients with moderate-to-severe GO who receive Tx versus ATD without surgery. Main outcome variables include: muscle index measurements via ultrasound and thyroid antibody levels. Additional outcome variables include: Clinical Activity Score (CAScore), NOSPECS score, superonasal index measurements via ultrasound, and quality of life score.

This study should allow for better therapeutic choices in patients with moderate-to-severe GO. In addition, it should demonstrate whether the outcome of GO in patients with moderate-to-severe GO is better in those who receive early Tx versus further ATD. Furthermore, this study will aim to establish a standard glucocorticoid scheme before and after Tx in patients with moderate-to-severe EO.

Eudra-CT: 2015-003515-38; Medical University of Vienna Protocol Record 1839/2015. Date of Ethics Committee approval: 19 January 2017. Registered on 27 January 2017.