This book offers ophthalmologists and medical practitioners a concise, data-driven review of the information that is most relevant in guiding the diagnosis and management of thyroid eye disease (TED). Particular attention is devoted to research and clinical trials that have advanced the field in recent years. Progress in our understanding of the pathogenesis of TED is described, and the heterogeneous natural history of TED is discussed to facilitate preemptive interventions. Advances in diagnostic evaluation, including autoantibody assessment, are reviewed with regard to their clinical utility. The diagnostic features of euthyroid TED are also carefully covered since these patients often represent a diagnostic dilemma. All relevant aspects of treatment are addressed including the role of radioactive iodine, long-term medical therapy, and surgical thyroidectomy. The impact of these treatment modalities on eye disease are discussed. Management of active TED is reviewed according to the severity of disease and in the light of recent findings and the introduction of novel agents. The discussion encompasses the role of steroids and other agents, the use of novel biologics, the medical and surgical treatment of optic neuropathy, and minimally invasive, customized reconstructive surgery. Numerous supporting images are included, and helpful checklists will aid the practitioner in treatment decision making.