Endocrine orbitopathy (EO) is a chronic, multisystem autoimmune disorder caused by lymphocyte infiltration, edema, and proliferation of endo-orbital connective tissue. These conditions involve the extraocular muscles, intraconal and extraconal fat, and, to a lesser extent, the lacrimal gland.Endocrine orbitopathy may be associated with toxic diffuse goiter and/or pretibial myxedema (Graves disease) and may appear without alterations in thyroid function (euthyroidism). It is characterized by antibodies that stimulate a general fibroblastic reaction (thyroid gland and lower extremities) and involves orbital fat tissue and muscles. The clinical signs and symptoms of EO reflect the mechanical consequences of increased orbital tissue volume and pressure within the orbit. Endocrine orbitopathy is marked by chronic evolution and, at times, a malignant outcome.