Scores the 7-item Clinical Activity Score and suggests an EUGOGO severity category for thyroid eye disease (Graves' orbitopathy).
This page helps record disease activity and suggests a severity category using published criteria. It is not a diagnostic or treatment tool and does not replace examination by an eye specialist. Read these limitations before relying on a result.
Sources: EUGOGO 2021 guideline (reference 1); Dickinson and Perros 2001 (reference 2). Interpretations made by AutoimmuneCalc carry no reference number.
How to use it. Part 1 records the seven Clinical Activity Score items as present or absent. Part 2 records the features EUGOGO uses to classify severity. Each part works on its own.
Thyroid eye disease, also called Graves' orbitopathy, is the main extrathyroidal manifestation of Graves' disease. Doctors describe it along two separate axes. Activity asks whether orbital inflammation is present, which matters because immunomodulatory treatment can only help during the active phase. Severity asks how much functional or cosmetic deficit exists[2]. The two overlap but are not the same: changing severity implies active disease, while the reverse is not necessarily true[2].
The 2021 EUGOGO guideline recommends assessing activity and severity with standardized criteria and categorizing each patient as active or inactive and as mild, moderate-to-severe, or sight-threatening. It also advises asking about quality of life[1]. Disease duration matters too, because anti-inflammatory and immunosuppressive treatment is significantly less effective after about 18 months[1].
| Measure | Rule |
|---|---|
| CAS (7 items) | One point per item present: spontaneous retrobulbar pain, pain on up or down gaze, eyelid redness, conjunctival redness, caruncle or plica swelling, eyelid swelling, and chemosis. Below 3 is inactive. 3 or more is active.[1] |
| 10-item CAS | Adds three progression items over 1 to 3 months: exophthalmos up 2 mm or more, eye movement down 8 degrees or more, and visual acuity down one line or more. No activity cut-off is given.[1] |
| Mild | Minor impact on daily life. Usually one or more of: lid retraction under 2 mm, mild soft-tissue involvement, exophthalmos under 3 mm above normal, and no or intermittent diplopia with corneal exposure that responds to lubricants.[1] |
| Moderate-to-severe | Enough impact to justify immunosuppression if active or surgery if inactive. Usually two or more of: lid retraction of 2 mm or more, moderate or severe soft-tissue involvement, exophthalmos 3 mm or more above normal, and inconstant or constant diplopia.[1] |
| Sight-threatening | Dysthyroid optic neuropathy and/or corneal breakdown.[1] |
How this calculator suggests a severity category. Corneal breakdown or optic neuropathy gives sight-threatening. Two or more moderate-to-severe features give moderate-to-severe. Exactly one is reported as needing clinical judgment, because the guideline's wording does not cover it. Only mild-level features give mild. This is our implementation of the table, not a rule stated in the guideline.
Reference only, without doses. Treatment depends on risk factors, thyroid status, contraindications, and shared decision-making[1].
| Category | Guideline summary |
|---|---|
| Mild | Local treatment with artificial tears, control of risk factors such as smoking and thyroid dysfunction, and referral of at-risk patients to a combined thyroid-eye clinic. A 6-month course of selenium is recommended for mild and active disease of recent onset (recommendations 2, 6, 7). |
| Moderate-to-severe and active | Intravenous methylprednisolone with mycophenolate is the first-line treatment. Second-line options include a second steroid course, oral steroids with a steroid-sparing drug, orbital radiotherapy, teprotumumab, rituximab, and tocilizumab (recommendations 22 to 25). |
| Moderate-to-severe and inactive | Rehabilitative surgery, such as orbital decompression, strabismus, and eyelid surgery, for residual manifestations. |
| Sight-threatening | An emergency. Optic neuropathy is treated immediately with high-dose intravenous methylprednisolone, with urgent orbital decompression if the response is absent or poor within 1 to 2 weeks. Severe corneal exposure needs urgent treatment (recommendations 26 and 27). |
The CAS is a checklist of seven inflammatory signs and symptoms of thyroid eye disease (Graves' orbitopathy): two kinds of pain, redness of the eyelids and conjunctiva, and swelling of the caruncle or plica, the eyelids, and the conjunctiva. Each present item scores one point, for a maximum of 7.
The 2021 EUGOGO guideline defines disease as active when the CAS is 3 or more out of 7 and inactive when it is below 3.
It adds three signs of recent progression over 1 to 3 months: an increase in exophthalmos of at least 2 mm, a decrease in eye movement of at least 8 degrees in any direction of gaze, and a decrease in visual acuity of at least one Snellen line. The guideline says it is useful for judging progression after the first visit. The sources give no activity cut-off for the 10-item score.
EUGOGO describes three groups. Mild disease has minor impact on daily life. Moderate-to-severe disease is serious enough to justify the risks of immunosuppression if active or of surgery if inactive. Sight-threatening disease means dysthyroid optic neuropathy or corneal breakdown.
Patients usually have two or more of: lid retraction of 2 mm or more, moderate or severe soft-tissue involvement, exophthalmos 3 mm or more above normal for race and gender, and inconstant or constant diplopia.
The guideline table uses the word usually and has no rule for a patient with exactly one moderate-to-severe feature. Rather than guess, the calculator reports that case as needing clinical judgment, especially about impact on daily life.
No. It shows a reference summary of what the 2021 EUGOGO guideline says for each category, without doses. Sight-threatening disease is an emergency that needs immediate treatment and specialist care.
Items, thresholds, and severity features were taken from Tables 2 and 3 of the EUGOGO 2021 guideline, and item definitions from the Dickinson and Perros atlas, then tested against hand-calculated cases for every rule and boundary. Every place where we interpreted the sources is listed under limitations. The page was reviewed by Mahiar Rabie, MS, MD.
Page history. October 8, 2026: page published.