Table 1.

Activity and Severity Definitions for Patients with Thyroid Eye Disease

A. Activity

1. Clinical activity score

The 7-item CAS is shown hereunder. Each item scores 1 point if presenta

Spontaneous retrobulbar pain

Pain on attempted up or lateral gaze

Redness of the eyelids

Redness of the conjunctiva

Swelling of the eyelids

Inflammation of the caruncle and/or plica (Fig. 2b)

Conjunctival edema, also known as chemosis (Fig. 2c)

2. Active TED

A CAS ≥3/7 usually implies active TED. A history or documentation of progression of TED based on subjective or objective worsening of vision, soft tissue inflammation, motility, or proptosis is suggestive of active TED independently of the CAS

B. Severity

1. Sight-threatening TED

Patients with DON and/or corneal breakdown and/or globe subluxation (Fig. 2f)

2. Moderate-to-severe TED

Patients without sight-threatening disease whose eye disease has sufficient impact on daily life to justify the risks of medical or surgical intervention. Patients with moderate-to-severe TED usually have any one or more of the following: lid retraction ≥2 mm, moderate or severe soft tissue involvement, proptosis ≥3 mm above normal for race and sex, or diplopia (Gorman score 2–3).

3. Mild TED

Patients whose features of TED have only a minor impact on daily life insufficient to justify immunosuppressive or surgical treatment. They usually have only one or more of the following: minor lid retraction (<2 mm), mild soft tissue involvement, proptosis <3 mm above normal for race and sex, transient or no diplopia, and corneal exposure responsive to lubricants.

^a A 10-item CAS is also sometimes used and includes additional points for increase of at least 2 mm in proptosis, decrease of at least 8° in any duction, and decrease of visual acuity by two lines. A limitation of the 10-item CAS is that it requires an earlier assessment of the mentioned measures, which is usually unavailable on first consultation. See Bartalena et al.¹⁹

CAS, clinical activity score; DON, dysthyroid optic neuropathy; TED, thyroid eye disease.