Thyroid eye disease causes the muscles and soft tissues within the eye socket to swell. This pushes the eyeball forward and causes various eye symptoms. Treatment involves steps to protect the eye as the disease runs its course. This may involve artificial tears, medicines and, in some cases, surgery. Thyroid eye disease is usually associated with an abnormality of thyroid gland function. This also needs to be treated.
Thyroid eye disease (TED) is a disease marked by swelling of the muscles and fatty tissues surrounding the eyeball within the eye socket (orbit).
The swelling is due to inflammation of these tissues. There is limited space inside the orbit so, as the tissues swell, the eyeball is pushed forward. This causes the clear window in the front part of the eye (the cornea) to lose its protection, which is provided by the eyelids. The eyeball cannot move so easily as the muscles that control it work less well. When the disease is very severe, the nerve connecting the eyeball to the brain can be compressed and damaged. This period of swelling is followed by a healing response.
TED is sometimes called other names such as thyroid ophthalmopathy, dysthyroid eye disease, Graves' ophthalmopathy or ophthalmic Graves' disease.
The thyroid gland is a small butterfly-shaped gland sitting near the top of your windpipe (trachea) at the front of your neck. It has an important role in controlling the speed at which chemical reactions happen in the tissues throughout your body (metabolic rate). The thyroid gland can become overactive or underactive. This is most often due to an autoimmune disease.
The immune system normally makes small proteins (antibodies) to attack germs (bacteria, viruses and other microbes). In people with autoimmune diseases, the immune system makes antibodies against tissues of the body. It is not clear why this happens. Some people have a tendency to develop autoimmune diseases. In such people, something might trigger the immune system to attack the body's own tissues.
Autoimmune thyroid disease occurs when the body's antibodies attack the thyroid gland. In some people, these same antibodies also attack the tissues surrounding the eyeball. This is TED. It is not known exactly why this happens in some people and not in others. So, TED is an autoimmune disease, most often occurring in association with an overactive thyroid gland. Occasionally, TED occurs when the thyroid gland appears to be working normally. However, people with an apparently normal thyroid gland at the time of TED have usually had abnormal thyroid function in the past or they go on to develop abnormal thyroid function in the future.
This is a rare condition affecting about 16 women in every 100,000 people and 3 men in every 100,000 people each year. Most of these people have a problem with an overactive thyroid gland and have an underlying autoimmune condition. It generally occurs in middle age. Some people carry genes that makes it more likely that they will get thyroid eye disease. It is also more likely to develop if you smoke.
Symptoms are caused by the tissues of the eye socket swelling and pushing the eyeball forward:
The two eyeballs are not always equally affected. You may have other non-eye symptoms due to the abnormal thyroid gland.
Diagnosis can be made simply on examining your eyes if you already have a diagnosis of a thyroid gland problem.
Sometimes, blood tests are needed to back up the diagnosis. They look at how well the thyroid gland is functioning by measuring its chemical messengers (hormones) in your bloodstream. These are called thyroid function tests (TFTs). More specialised blood tests can be done to measure the antibodies in your blood.
Occasionally, thyroid scans need to be done to see how actively the thyroid gland is working (uptake scans). If the doctors are particularly concerned about the swelling in the orbit, they may organise a scan (known as an MRI) which will show up which tissues have been most affected.
Doctors will want to assess your general sight carefully, including how well you see colours and how good the vision out of the corner of your eye (your peripheral vision) is. They may also want to carry out an eye movement test to see how much the muscles have been affected. These assessments will be repeated throughout the course of the disease.
This is a self-limiting disease: if left untreated, the inflammation will gradually go by itself. But, the symptoms caused by the swelling (such as bulging eyes) may remain, as some of the tissues that have been stretched may not always be able to return to their original form. The aim of treatment is mainly to limit damage occurring during the inflamed period. There are also treatments for people whose tissues have not been able to return to their original form after the inflammation has settled. The eye problems will be managed by an eye doctor (ophthalmologist) and the underlying thyroid problem by your own doctor or by a a specialist in the hormone systems of the body (an endocrinologist).
If you develop double vision (diplopia), you may be referred to a specialist health professional who manages problems with eye muscles (an orthoptist). They may give you modified glasses that block off vision from one eye (like a patch) or put a special cover, called a prism, over one side to stop the diplopia.
Radiotherapy (treatment by exposure to a radioactive substance) may be used in some places on some people. The aim is to reduce the swelling in the eye. It is used alongside other forms of treatment.
There are a number of new treatments that are being investigated. They are still in the pipeline but a lot of work is being done to improve the options for people with TED.
Additionally, your doctors will treat any abnormality of thyroid function. This is usually with tablets but may also include radioactive iodine or, uncommonly, surgery to the thyroid gland.
Yes. Here are a few tips:
Most people do not develop permanent complications. However, they do occur in some people, especially those where treatment is delayed or where the TED has been severe. They are also more likely in older people, in those who smoke and in people with diabetes. Possible complications include:
Complications from the disease
Complications from treatment
This is a drawn-out illness. The inflamed period tends to last months to years (usually about two years). However, for most people it will be a mild disease needing lubricants and regular assessments only. It 'burns out' (fades away) by itself. For those with more severe disease, the outlook depends on how early it is diagnosed and how intensive the treatment is. About 1 in 4 people will end up with reduced eyesight.