Thyroid eye disease: risks, symptoms, causes and treatment

Thyroid eye disease (TED), also known as Graves' ophthalmopathy or thyroid-associated orbitopathy, is a condition that affects the eyes and is often linked to an overactive thyroid gland (hyperthyroidism). This guide explains the risks, symptoms, causes and treatments for this complex condition.

Who is at risk?

Thyroid eye disease mainly affects people with hyperthyroidism, although it can also occur in people whose thyroid works normally or is underactive. Other risk factors include:

• Gender: women are more likely to develop TED than men.
• Smoking: smoking increases both the risk and the severity of TED.
• Genetics: a family history of thyroid disorders or autoimmune diseases can make TED more likely.
• Age: TED usually occurs between the ages of 30 and 50, although it can affect people of any age.

Symptoms of thyroid eye disease

Symptoms vary in severity and may include:

• Bulging eyes (proptosis): the eyes may push forward because the muscles and tissues behind them swell.
• Redness and irritation: the eyes may look red and inflamed and feel gritty or dry.
• Double vision (diplopia): misalignment of the eyes can cause double vision.
• Eyelid retraction: the upper eyelids may be pulled up, making it hard to close the eyes fully.
• Swelling and inflammation: the tissues around the eyes may become swollen and tender to the touch.
• Changes in vision: blurred vision or reduced sharpness of vision can occur because of pressure on the optic nerve.

What causes thyroid eye disease?

Thyroid eye disease is an autoimmune condition: the body's immune system mistakenly attacks its own tissues. In TED, it targets the muscles and tissues around the eyes, causing inflammation and swelling.

The exact cause of this autoimmune response is not fully understood. It is thought to involve a combination of genetic tendency and environmental factors such as smoking and stress. Levels of certain immune system proteins called cytokines may also play a part in how TED develops and progresses.

Treatment of thyroid eye disease

Thyroid eye disease is often managed by a team that includes endocrinologists (hormone specialists), ophthalmologists and sometimes surgeons. Treatment aims to relieve symptoms, prevent complications and improve quality of life. Options include:

• Medicines: corticosteroids such as prednisone may be prescribed to reduce inflammation and swelling. Other medicines, such as immunosuppressants or biologics, may be used in severe cases or when steroids don't work.
• Eye drops and lubricants: lubricating eye drops relieve dryness and irritation, and anti-inflammatory drops may be prescribed to reduce inflammation and redness.
• Teprotumumab: this biologic medicine, approved by the US FDA, targets the underlying process of TED by blocking a specific pathway involved in inflammation and tissue remodelling. In clinical trials it improved eye bulging and other symptoms.
• Surgery: in severe TED, or when other treatments haven't worked, surgery may be needed to correct eye misalignment, reduce bulging or relieve pressure on the optic nerve. Options include orbital decompression, eyelid surgery and strabismus (squint) surgery. See oculoplasty for the eyelid and eye-socket care the hospital provides.
• Stopping smoking: quitting smoking is essential, because smoking can worsen symptoms and increase the risk of complications.

In short

Thyroid eye disease is a complex condition that can affect both physical and emotional well-being. Early detection and prompt treatment are essential to reduce symptoms and prevent long-term complications. If you notice symptoms such as bulging eyes, redness or double vision, see an ophthalmologist (eye specialist).