Thyroid eye disease (TED) is a condition that causes the muscles and soft tissues of your eye socket to swell. It happens when you have a problem with your thyroidgland. It is also called thyroid associated ophthalmopathy (TAO), thyroidorbitopathy or Graves’ orbitopathy or ophthalmopathy.
TED affects the soft tissues such as the fat and muscles surrounding your eyeball within your eye socket. The condition is characterised by a period of inflammation and swelling of these tissues (active stage), followed by an inactive (or ‘burnt out’ stage). It usually happens when you have a problem with your thyroid gland, although in some people, it can happen when the thyroid gland is working normally.