Thyroid Eye Disease: An Overview

From ThyroWorld Volume 1, No 2, Autumn 1998.

What is TED? Thyroid eye disease (TED) is a condition that affects some people with an overactive thyroid gland. Occasionally it occurs in people with an underactive thyroid or rarely when there is no thyroid problem. The appearance of a person with TED is characteristic. Some well-known people with TED include former American First Lady Barbara Bush and actors Maria Aitken, Marty Feldman and Miriam Karlin. The eyes usually protrude and become starey, red and inflamed. Bags appear above and below the eyes. Sometimes patients develop obvious squints. TED is therefore a very specific condition with characteristic features; it is not any type of eye condition that may occur in a person with an overactive thyroid gland (for example, glaucoma, detached retina, etc).

Most people who are unfortunate enough to get TED have mild eye problems but in a few the condition can be severe and cause serious damage to vision. Common symptoms include irritable eyes, excessive watering, smarting and aching behind the eyes. In more advanced cases, there is double vision and persistent blurred vision. Because TED is relatively rare, the diagnosis can be missed. Frequently it is misdiagnosed as conjunctivitis or an allergy. In most patients the eyes settle down with time, although this can take years and usually the appearance of the eyes does not return entirely to normal. A few patients get worse and require treatment.

What causes TED? There is a close link between TED and thyroid disease. TED can come on before or after the onset of the thyroid overactivity, though usually the two coincide. We now know that the thyroid overactivity is caused by an immune reaction against the thyroid gland. It is likely that a similar process causes TED. Stress may also play a role. A striking majority of patients with TED are smokers, so smoking probably makes the disease worse. Whatever the cause, the muscles behind the eyes which control eye movements become inflamed and swollen. The muscles cannot be seen, but the swelling causes the protrusion and staring appearance of the eyes.

How does TED affect patients? For some people TED has devastating effects because of the physical discomfort and visual disability. The disease also has serious psychological effects because of the altered facial appearance which undermines self-confidence to the extent that some sufferers become socially isolated and experience difficulties coping at work and in their home.

What treatments are available for patients with TED? All patients with Graves' disease and TED should have regular thyroid checks to ensure that the function of the thyroid gland is maintained as normal as possible. Thyroid gland over- or underactivity tends to make the eyes worse. All patients with TED should be encouraged to stop smoking as smoking probably makes the eye disease worse. Artificial tear substitutes help some of the common symptoms (excessive watering of the eyes, smarting and irritation). Most patients get better with time and simply require reassurance.

Severe cases should be referred to a specialist centre for further assessment and treatment. High doses of steroids, radiotherapy or an operation may be offered if there is severe inflammation, particularly when the disease appears to be getting worse rather than better with time. Once the inflammation has settled (this usually takes several months), further surgery can be undertaken to correct severe squints, and to improve the appearance of the eyes (for instance to lower the upper lids, and remove "bags" around the eyes). Best results are usually achieved in centres which have an interest and experience in treating TED.

P Kendall-Taylor, Professor of Endocrinology
Dr. Petros Perros, Consultant Endocrinologist
Miss A J Dickinson, Consultant Ophthalmologist

Newcastle upon Tyne
March 1998

Copyright © 1998 TED Thyroid Eye Disease Association