Pathogenesis of Thyroid Eye Disease.

Thyroid eye disease (TED), also known as Graves ophthalmopathy, Graves orbitopathy, and thyroid-associated ophthalmopathy is an in- fl ammatory autoimmune disease, which results in the progressive enlargement of the orbital extraocular muscle and tissues. 1 – 3 Orbital fi broblasts, the primary autoimmune target cells in TED, are capable of responding to immune stimuli and amplifying the orbital in fl ammatory process. 4 – 6 The resultant in fl ammation, orbital tissue volume expansion, and remodeling lead to the characteristic clinical fi ndings in TED, such as upper eyelid retraction, edema and erythema of the periorbital tissues and conjunctivae, and proptosis. Approximately 3% to 5% of TED patients develop vision-threatening changes from corneal exposure/ ulceration or compressive optic neuropathy. 6 During inactive disease, atrophy and fi brosis of the muscle fi bers occur, which may result in a persistent restrictive strabismus. 6 To date, there are no effective methods to prevent