Thyroid Eye Disease
Thyroid eye disease (TED) is an autoimmune condition in which there is inflammation of the tissues around the eye. It causes swelling of the muscles that move the eye, the fat behind the eye, the skin on the eyelids and the conjunctival lining of the eye.
Normally the body produces antibodies, which protect the body by helping to fight against germs that cause infections. In autoimmune conditions, these antibodies attack normal tissues. We do not understand why this happens, nor do we know why it occurs in certain people; we do know that some people have an increased tendency to develop autoimmune conditions and it often runs in families.
In TED, the antibodies produced to attack the tissues behind the eyes, causing a cascade of reactions that cause inflammation and swelling. These same antibodies can attack the thyroid gland, which is a small gland in the neck that produces hormones that control the speed of chemical processes (metabolism) in your body.
Commonly, a thyroid disorder, particularly hyperthyroidism (overactive thyroid) or Graves disease, is diagnosed before TED and it may be the endocrinologist or GP who is treating the thyroid problem that refers you to an eye doctor.
A significant proportion of people develop TED before they have thyroid disease and these people can be more difficult to detect as their thyroid function blood tests are normal. Their thyroid antibody tests are usually raised, but this is only discovered if specifically requested when doing the blood test; unlike thyroid function tests they are not routinely performed blood tests.
Occasionally TED develops in people who never had and never develop a thyroid disorder. TED can also occur before or after hypothyroidism (underactive thyroid).
TED can affect different people in different ways, ranging from mild disease (the most common) to severe, sight-threatening disease.
TED Symptoms include:
- Red eyes
- Watery eyes
- Puffy eyes
- Tired or uncomfortable eyes or a feeling of pressure behind the eyes
- Eyelid retraction, with or without forward movement of the eye, causes a staring, bulgy eye appearance
- Double vision, with or without pain on eye movement
- Blurry vision, reduced colour vision and/or loss of vision
Our consultant at Clinica London Miss Olver has a particular interest in the impact of TED on quality of life. Her research has shown that TED has a significant effect on quality of life for most patients. She has developed an internationally recognised questionnaire to specifically assess the quality of life in patients with TED. This is useful in monitoring patients over time and assessing their response to treatment. It facilitates her discussions with patients in finding out what is important to them as opposed to just considering the clinical picture.
Active or Inactive Disease
Doctors will talk about the disease being active or inactive and mild or severe. Active disease means that the eyes are currently inflamed. Signs of inflammation are redness, swelling and pain. Usually, in TED, your eyes go through an early active ‘hot’ phase, which lasts one to two years on average, then it settles down and becomes inactive and ‘quiet’. At that stage, things may or may not be back to normal. Thus, you can have a severe inactive disease if the eyes are white and there is no more pain or swelling, but the eyes are still very pushed forwards (proposed) or you have a squint (strabismus), causing the eyes to look in different directions. When the disease is inactive and your eyes are stable then rehabilitative surgery may be appropriate.