The purpose of this study is to determine whether periorbital injection of glucocorticoid is effective and necessary in the treatment of mild TAO.

Inclusion Criteria:

General conditions:

1. clinically diagnosed as thyroid disease;
2. able and willing to participate in clinical trials and ensure regular follow-up.

Eye condition:

1. patients with monocular disease diagnosed by TAO;
2. EUGOGO/NOSPECS grade was mild and CAS score was less than 3;
3. the course of eye disease was less than 12mo and had not been treated in the past.

Exclusion Criteria:

General situation:

1. patients with poor blood glucose control in recent 3 months, glycosylation ≥ 10% ;
2. blood pressure still fluctuated > 180/110mmHg after medication;
3. obvious liver and kidney insufficiency;
4. contraindications for the use of glucocorticoids (peptic ulcer, osteoporosis, severe infection, psychosis, etc.);
5. patients with severe abnormal blood coagulation;
6. patients with other systemic immune diseases;
7. any uncontrollable clinical problems (severe mental, neurological, cardiovascular, respiratory and other systemic diseases and malignant tumors);
8. history of chronic infection;
9. pregnant and lactating women.

Eye conditions:

1. B-ultrasound or CT, MRI found other diseases causing exophthalmos (intraorbital space occupying lesion, inflammatory pseudotumor, neurofibroma, etc.);
2. moderate to severe TAO, in either eye requiring local or systemic treatment;
3. periorbital infectious diseases, hemorrhagic diseases;
4. uveitis, glaucoma, high myopia, diabetic retinopathy and other eye diseases.
5. those who studied the eyes who had a history of arbitrary surgery;
6. those who were considered by the researchers to be excluded.