Clinical assessment of TED is aimed to answer 2 questions: 1) Is the disease active or inactive? and 2) Is the disease mild, moderate/severe, or sight-threatening?
Activity of the Disease
To assess activity, the most commonly used system is the Clinical Activity Score (CAS). At the initial visit CAS is reported on a scale of 1 to 7 and assigns points for the following: spontaneous orbital pain, gaze-evoked orbital pain, eyelid swelling due to active TED, eyelid erythema, conjunctival redness due to active TED, chemosis, or caruncle/plica inflammation. An initial score of 3 or greater is considered active disease. On follow-up visit, CAS is scored out of 10 to include increase of more than 2 mm in proptosis, decrease in ocular excursion in any one direction of more than 8°, and decrease of acuity equivalent to 1 Snellen line. A follow-up score of 4 or greater is considered active disease.
Severity of the Disease
Severity is a function of the degree of diplopia, proptosis, and soft-tissue changes, as well as the impact on quality of life (QoL). It is categorized by the European Group on Graves' Orbitopathy (EUGOGO) guidelines. Diplopia is classified as absent or transient, inconstant (at the extremes of gaze), or constant. Proptosis is measured through a Hertel exophthalmometer, which can be obtained and used by endocrinologists. QoL can be assessed via a validated EUGOGO questionnaire (https://www.eugogo.eu/eugogo-service/downloads/quality-of-life-questionnaire). Mild TED is TED that has a minor impact on QoL with one or more of the following: lid retraction less than 2 mm, mild soft-tissue involvement, proptosis less than 3 mm, and transient or absent diplopia. Moderate to severe TED is disease that is not sight-threatening but has a sufficient impact on the QoL to justify the risks of immunosuppressive or other systemic therapy (if active) or rehabilitative surgery (if inactive). This involves one or more of the following: moderate or severe soft-tissue involvement, proptosis greater than 3 mm, and inconstant or constant diplopia. Finally, sight-threatening disease has either CON or corneal breakdown limiting vision.
Role of the Endocrinologist
Endocrinologists play an important role in the prompt diagnosis of TED because they see patients with dysthyroidism regularly. In addition to modifying risk factors for TED by maintaining euthyroidism, counseling about strict tobacco avoidance, and using radioactive iodine judiciously, endocrinologists need to determine who needs ophthalmologic evaluation and how urgently. All GD patients should be evaluated for the presence of ocular symptoms. If symptoms are present, one should obtain a CAS and assess the degree of diplopia, proptosis, soft-tissue changes, and QoL.[19,20] If the patient has TED findings, a nonurgent evaluation by ophthalmology for a baseline comprehensive eye assessment is indicated. A screening protocol and recommendations for referral are also outlined in the 2008 EUGOGO consensus statement. Sight-threatening disease can also be evaluated by the endocrinologist (Figure 3). The risk of corneal compromise can be assessed by evaluating for lagophthalmos (failure to fully close the lids when asking the patient to gently close the eyes). Optic nerve health can be assessed by evaluation for a relative APD using a penlight, assessment of visual acuity using a Snellen chart, and assessment of color perception using Ishihara plates (available for free online). Orbital imaging can be obtained to assess for optic nerve compression if the clinical exam suggests optic nerve compromise. Should there be any concern for sight-threatening disease, urgent evaluation by ophthalmology is indicated.
Endocrinologist's assessment for sight-threatening disease. The optic nerve and cornea can be evaluated for evidence of sight-threatening disease. Items in red can be assessed by the endocrinologist in the clinic. Any suspicion for sight-threatening disease should prompt urgent referral to the ophthalmologist for urgent intervention.
Role of the Ophthalmologist
Ophthalmologists specializing in TED, typically oculoplastic orbital surgeons, should be involved in TED diagnosis and management. A collaborative relationship between the endocrinologist and ophthalmologist is ideal to provide the most comprehensive care. Patients with TED should be referred for ophthalmic evaluation. A complete eye exam can differentiate common ocular conditions such as dry eye or allergies from TED. Additionally, a baseline eye exam is helpful to compare progressive symptoms of TED against. Finally, CON can occur silently and requires optic nerve evaluation and visual field testing. The ophthalmologist will help determine whether the disease is active, manage ocular symptoms and coexisting ocular conditions, and work with the endocrinologist to manage TED.
J Endo Soc. 2021;5(5) © 2021 Endocrine Society