Criteria 1 - Eyelid retraction with:
(1) thyroid gland abnormality
OR
(2) exophthalmos
OR
(3) optic nerve dysfunction
OR
(4) extraocular muscle involvement
Criteria 2 - Thyroid gland abnormality AND absent eyelid retraction with:
(1) exophthalmos
OR
(2) optic nerve dysfunction
OR
(3) extraocular muscle involvement
where:
• Eyelid retraction = upper eyelid either at or above superior corneoscleral limbus
• Exophthalmos = exophthalmometer reading >= 20 mm
• Thyroid gland abnormality = (a) goiter OR (b) laboratory evidence of hyperthyroidism
• Laboratory evidence of hyperthyroidism = decreased TSH AND (increased free thyroxine OR increased triiodothyronine)
• Optic nerve dysfunction = (a) reduced visual acuity, (b) reduced color vision (c) reduced visual field, OR (d) abnormal pupillary reaction
• Extraocular muscle involvement = (a) impaired ocular movements (restrictive myopathy), OR (b) enlarged muscle on MRI, CT or ultrasonography
• Confounding causes must be excluded (inflammatory pseudotumor, malignant lymphoma, sarcoidosis, amyloidosis, vasculitis, contiguous sinus disease, cellulitis, orbital tumors, orbital vascular malformations, posterior commissure brain lesions, lithium or corticosteroid induced proptosis, hydrocephalus).