TG and Graves disease: Thyroid eye disease (TED), also known as Graves' orbitopathy or ophthalmopathy (GO) or Graves' eye disease, is an autoimmune condition of the retroocular tissues associated with Graves' disease. In isolated GO, the patient can present without thyroid hormone dysfunction or systemic symptoms of Graves' disease, in which case it is called euthyroid Graves' ophthalmopathy (EGO).