From the Guidelines
To diagnose Graves' orbitopathy, a comprehensive eye examination, including assessment of mechanical restriction, exophthalmometry, and imaging studies such as orbital CT or MRI, is recommended. This approach is based on the most recent and highest quality study, which emphasizes the importance of a full sensorimotor examination, noting evidence of mechanical restriction, and the use of forced ductions to confirm restriction 1. The examination should also include binocular field testing, measurement of exophthalmos, surveillance for optic neuropathy, and ocular coherence tomography and Humphrey visual fields to screen for or monitor possible associated compressive optic neuropathy.
Key components of the diagnostic evaluation include:
- Clinical eye examination to assess eye protrusion, eyelid retraction, and eye movement restrictions
- Exophthalmometry to measure the degree of eye protrusion
- Imaging studies, such as CT or MRI scans of the orbits, to evaluate eye muscle enlargement and orbital fat expansion
- Visual field testing to check for any vision impairment
- Surveillance for optic neuropathy, including assessment of acuity, color vision, visual fields, pupillary exam, and fundus exam
It is also important to note that thyroid function and associated immune studies may be ordered, although this is typically handled by the associated primary care or endocrinology specialist 1. The combination of clinical signs, imaging results, and thyroid function tests provides a comprehensive evaluation of Graves' orbitopathy, allowing for appropriate treatment planning.
From the Research
Diagnosis of Graves' Orbitopathy
The diagnosis of Graves' orbitopathy is primarily based on clinical findings and laboratory tests, with imaging studies playing a crucial role in assessing orbital changes and disease progression. The following methods are used to diagnose Graves' orbitopathy:
- Clinical evaluation, including visual acuity testing, biomicroscopy, and applanation tonometry 2
- Laboratory tests indicative of thyroid dysfunction and autoimmunity 3, 4
- Imaging studies, such as:
- Computed tomography (CT) to evaluate morphological abnormalities of the orbital structures 5, 3, 6, 2
- Magnetic resonance imaging (MRI) to demonstrate orbital pathology and evaluate disease severity 5, 3, 6
- Ultrasonography to provide information about the condition of retrobulbar adipose tissue and the thickness of extraocular muscles 2
- Color Doppler imaging to aid in the diagnosis and management of Graves' orbitopathy 3
Diagnostic Criteria
The diagnostic criteria for Graves' orbitopathy include:
- Eyelid retraction in association with objective evidence of thyroid dysfunction or abnormal regulation 4
- Exophthalmos, optic nerve dysfunction, or extraocular muscle involvement 4
- Presence of ophthalmic signs, such as conjunctival chemosis, periorbital edema, and bilateral ptosis 2
- Absence of confounding causes for the ophthalmic features 4
Classification of Disease Severity
The severity of Graves' orbitopathy can be classified using various systems, including: