Introduction
  Graves' ophthalmopathy (GO) or thyroid-associated ophthalmopathy (TAO) is one of the remaining enigmas in thyroidology, for the basic scientist as well as for the clinician. For, its immunopathogenesis is incompletely understood and its management can be rather difficult. The last ten years have witnessed considerable progress as quite a few basic and clinical studies have clarified many relevant issues, providing a scientific basis for the proposed immunopathogenesis and for the outline of a treatment plan. Nevertheless, there are remaining controversies in both areas which are currently heavily debated. This simply might indicate that the definitive evidence is still not sufficient to answer questions like: what is the responsible autoantigen? is GO a T- or B-cell mediated disease? what is the most appropriate treatment of Graves' hyperthyroidism that will not harm the eyes? what is the role of immunosuppressive treatment? It is thus timely to review in a concise manner what is known on GO, what is not known, and what is disagreed upon.