Summary
Thyroid eye disease (TED) is characterized by progressive inflammation and damage to tissues around the eyes, especially extraocular muscle, connective and fatty tissue. TED has an active disease phase in which progressive inflammation, swelling and tissue changes occur. This phase is associated with a variety of symptoms including pain, a gritty feeling in the eyes, swelling or abnormal positioning of the eyelids, watery eyes, bulging eyes (proptosis) and double vision (diplopia). The active phase can last anywhere from approximately 6 months to 2 years. This is followed by an inactive phase in which the disease progression has stopped. However, some symptoms such as double vision and bulging eyes can remain. In some people, cosmetic changes and significant disability can develop. Although uncommon, in severe instances, vision loss can occur. Thyroid eye disease is an autoimmune disorder. An autoimmune disorder is one in which the body’s adaptive immune system, which protects the body from infectious or other foreign substances, mistakenly attacks healthy tissue instead. Treatment includes reversing hyperthyroidism, specific medications, supportive measures and in some patients, surgery.
Introduction
Thyroid eye disease most commonly occurs as part of Graves’ disease, which is an autoimmune disease that affects the thyroid and often the skin and eyes. The thyroid is a butterfly-shaped gland located at the base of the neck. The thyroid is part of the endocrine system, the network of glands that secrete hormones that regulate the chemical processes (metabolism) that influence the body’s activities as well as regulating the heart rate, body temperature and blood pressure. Graves’ disease is characterized by abnormal enlargement of the thyroid (goiter) and increased secretion of thyroid hormone (hyperthyroidism). Less often, thyroid eye disease can occur in people who have or have had an overactive thyroid (hyperthyroidism) or in individuals with an underactive thyroid (hypothyroidism) such as people who have a disorder called Hashimoto thyroiditis.
Although relatively infrequent, TED does not currently fulfill the main criterion for being defined as a rare disease, but several variants of the disease are considered rare diseases.
