The Clinical Activity Score (CAS) for thyroid eye disease uses 7 parameters in follow-up. The minimum CAS score that defines ACTIVE thyroid eye disease requiring immunosuppressive treatment is:
- A CAS ≥ 3/7 ✓
- B CAS ≥ 2/7
- C CAS ≥ 4/7
- D CAS ≥ 5/7
Correct answer: A. CAS ≥ 3/7
Explanation
The Clinical Activity Score (CAS) assesses 7 signs of inflammation in thyroid eye disease: spontaneous orbital pain, gaze-evoked pain, eyelid erythema, eyelid edema/swelling, conjunctival redness, chemosis, and caruncle/plica inflammation. A score of ≥3/7 (or ≥4/10 on the 10-item initial assessment version) indicates active disease where immunosuppressive therapy (IV methylprednisolone) is expected to be beneficial. CAS ≥3/7 is the established European Group on Graves' Orbitopathy (EUGOGO) threshold for active disease.
Reference: Khurana Comprehensive Ophthalmology, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.