Thyroid Eye Disease
What is Thyroid Eye Disease?
Thyroid eye disease is a rare disease that affects the skin, underlying muscle and fat around the eyes, eyebrows, cheeks and eye sockets causing inflammation. It occurs in a small proportion of patients that are susceptible to immune thyroid disease and can come on before the thyroid gland changes, at the same time as the thyroid changes or even years later. Most often, however, it is within a few months on either side of the start of the thyroid disorder.
Both eye disease and thyroid disease are autoimmune diseases caused by a fault in the body’s defence mechanism in which antibodies attach to receptors in the thyroid gland causing it to become over or under-active. The same receptors are present in the tissues around the eye sockets and eyelids and cause inflammation.
Just like any inflamed tissue (think of an inflamed finger joint) the result is pain, redness, swelling, loss of function and increased temperature of the tissue. The pain can be a constant deep pain in the eye socket, or (if the muscles that move the eyes are affected) pain on eye movement. The eyelids and the white of the eye can become red and swollen and swelling of the fat and muscle behind the eye can cause bulging of the eye (proptosis or exophthalmos). The visual function can be reduced if swelling in the eye socket compresses the optic nerve and loss of colour vision is the first sign of this, so patients have their vision and colour vision checked at clinic visits.
The inflammation is made very much worse by smoking – even passive smoking or vaping – with eight times the risk of severe eye disease, it is imperative to stop smoking. Most cases however are mild and can be controlled by using lubricating eye drops. Severe cases may need treatment with immunosuppressive drugs such as infusions of steroids. After the disease has settled (usually some months to a year or so) and there is no more active inflammation, surgery may be indicated in a small percentage of patients to reduce bulging of the eyes, double vision and eyelid changes.
I have been part of the Royal Free Thyroid Eye Disease multidisciplinary clinic for nearly 20 years and provide a comprehensive treatment of the condition in combination with endocrinologists, radiotherapists, orthoptists, ENT surgeons and psychologists.