Thyroid eye disease (TED) is an eye condition in which the eye muscles and fatty tissue behind the eye become inflamed. This can cause the eyes to be pushed forward so they look ‘staring’ or ‘bulging’, and the eyes and eyelids become swollen and red. In some cases the muscles that move the eyes become swollen or stiff so that the eyes are no longer in line with each other – this can cause double vision.

TED is an autoimmune disease. It occurs when the body’s immune system attacks the back of the eye and causes inflammation. It is mainly associated with an over-active thyroid gland that is caused by Graves’ disease. However, it does very occasionally occur in people with an under-active or normal thyroid. It is also linked to smoking and can be made worse by swings in thyroid levels from over-active to under-active. There is some evidence to suggest that TED can be affected by passive smoking.

TED is usually mild in the majority of children and it can be treated.

How common is it?

About a third of adults with Graves’ disease are affected by TED. Although TED in children is much less common, it can affect children as young as three years old. Studies have shown that children tend to have a less troublesome disease and only rarely require any surgical intervention.