Table 1 Subject inclusion and exclusion criteria

• GD and GO onset ≤ 12 months

• No previous GD treatment other than ATD

• First relapse after decrease of antithyroid medication within 4–6 months

• GO treatment with glucocorticoids based on the Kahaly scheme

• Patients under ATD with normal thyroid function or subclinical hyperthyroid function and moderate-to-severe GO

• Clinically active inflammation according to CAScore (≥ 3/7)

• Informed consent

• GD and GO onset ≥ 12 months

• More than one relapse of GO longer than 6 months from diagnosis

• Previous GD treatment by RAI or surgery

• SNI greater than 7.0

• Urgent orbital decompression surgery

• Loss of vision

• Loss of visual field

• Loss of color vision

• Patients not receiving glucocorticoids for GO

• Cytological findings of postsurgical histopathological results suspicious for malignancy

• Pregnancy or breastfeeding

• Contraindication to GC

• Halt of GC therapy

• Patients with diabetes mellitus

• Age below 18 years

• No informed consent