Thyroid Eye Disease: Understanding Causes & Treatments

Thyroid eye disease (TED) is an autoimmune thyroid disease that occurs when the body’s immune system mistakenly attacks healthy tissue surrounding the eye. Thyroid eye disease is associated with inflammation of the eye muscle, connective tissue, and fatty tissue surrounding the eye, leading to swelling and redness of the eyelids, vision changes such as double vision, and, rarely, blindness due to pressure on the optic nerve. 

Over time, the muscles that move the eye are thickened and stiff, causing the eyeball to push forward while the eyelids pull back, leading to “proptosis,” or the bulging of the eyeball. 

According to the American Academy of Ophthalmology, thyroid eye disease is up to 5 times more common in women than in men. The median age at diagnosis is the mid-40s, although TED can occur at any age. Thyroid eye disease tends to be more severe in older patients with a higher risk of complications. Find out the different signs of thyroid problems in women compared to signs of thyroid problems in men.

Other risk factors for developing TED include:

• Smoking or exposure to secondhand smoke 

• A family history of thyroid disorders 

• High blood cholesterol levels

• Selenium deficiency

• History of radioactive iodine treatment for thyroid disorder 

• Stress 

Find out 8 signs you may have a thyroid condition.

The Relationship Between Thyroid Eye Disease and Thyroid Hormone Levels

Thyroid eye disease mainly occurs in people with an overactive thyroid gland (hyperthyroidism) and high thyroid hormones. However, it can also occur in people with low thyroid hormones (hypothyroidism) or normal thyroid function, although this is less common. 

TED is most commonly associated with Graves’ disease. However, a person can develop TED without having Graves’ disease. 

Learn about hypothyroidism vs hyperthyroidism.

Causes and Risk Factors of Thyroid Eye Disease

Thyroid eye disease is a complex immune-mediated condition. It occurs when the body’s immune system makes antibodies that attack healthy body tissues. In autoimmune thyroid disease, circulating auto-antibodies attack cells in the thyroid gland as well as extrathyroidal cells (tissues outside the thyroid gland), such as the eye.

The Connection with Hyperthyroidism and Graves' Disease

Thyroid eye disease is closely associated with Graves’ disease, which is also an autoimmune disease. People with Graves’ disease have higher than normal thyroid hormone levels (hyperthyroidism). About a quarter of the people with Graves’ develop TED. Thyroid eye disease is also called Graves’ eye disease, Graves’ ophthalmopathy, or Graves’ orbitopathy. However, a person can develop TED without having Graves’ disease. 

Other Contributing Factors: Lifestyle and Genetic Predispositions

Thyroid eye disease occurs due to a combination of immune, genetic, and environmental factors. Risk factors for TED include:

• Female gender

• Older age (40s to 60s)

• Cigarette smoking and exposure to secondhand smoke

• History of radioactive iodine treatment for thyroid dysfunction

• High blood cholesterol levels

• Selenium deficiency

• Stress, which can contribute to worsening TED symptoms

Symptoms of Thyroid Eye Disease

• Diplopia (double vision) 

• Proptosis (swollen or bulging eyes) 

• Upper lid retraction (a pulled-back upper eyelid that makes it difficult to fully close the eyes, also called a thyroid stare)

• Blurred vision

• Eye pain or irritation

• Dryness or watering, redness, grittiness, and itching in the eyes

• Difficulty with eye movements

• Bags under the eyes

• Light sensitivity (intolerance of bright lights)

• Eyelid inflammation and swelling

• Lid lag (the upper eyelid is higher than normal when looking down)

• Proptosis (eyeball being pushed out of the eye socket, causing bulging of the eyeball)

• Vision loss (rare) due to compression of the optic nerve or formation of corneal ulcers

Phases of Thyroid Eye Disease: Active and Stabilizing

Active Thyroid Eye Disease

The active phase or inflammatory phase of thyroid eye disease typically lasts for 6 months to 3 years (average 2 years). Symptoms during this phase include worsening eye pain, redness, swelling, and bulging eyes. Early diagnosis and treatment during the active disease phase can help in reversing some of the symptoms and preventing serious sight-threatening complications.

Chronic Thyroid Eye Disease

The chronic phase, also called the inactive phase or fibrotic phase of thyroid eye disease, usually occurs after the first 18 months. It is associated with stable symptoms that do not get worse. However, proptosis (bulging eye), lid retraction, and double vision can continue to be present. This is called the fibrotic phase because scar tissue formation can lead to permanent double vision and other changes in the appearance and function of the eye.

When to See a Doctor

Make an appointment to see your doctor immediately if you have:

• Double vision.

• Blurred vision that does not improve when you cover one eye or blink.

• Changes in color vision (the colors appear faded or there is a difference in brightness or contrast when comparing one eye with the other).

• Blind spots.

• Vision loss.

• Worsening eye symptoms. 

Common Questions

What are 3 signs of thyroid eye disease?

Three common signs of thyroid eye disease are double vision, eye irritation, and bulging eyes.

What are the phases of thyroid eye disease?

The two phases of TED are the inflammatory phase (active thyroid eye disease) when symptoms are worsening and the chronic phase when symptoms are stable.

How quickly does TED progress?

TED typically progresses for 6 months to 3 years before stabilizing. However, some people are left with permanent changes in the appearance and function of the eyes. 

How bad is thyroid eye disease?

Most people with TED experience mild symptoms that can be treated with artificial tear drops and selenium supplements. Others have moderate to severe symptoms and require treatment with steroid medicine or other immunosuppressants. Surgery may be necessary in severe cases.

How does thyroid eye disease affect the eyes?

Thyroid eye disease affects the surrounding eye muscles, connective tissue, and fatty tissue behind the eyeball. Inflammation of these tissues pushes the eye forward, causing bulging and thyroid staring. It can also cause the eyelids to become irritated, red, and swollen. 

What can thyroid eye disease be mistaken for?

TED can be mistaken for eye allergies, dry eye, bacterial infections, blepharitis, and age-related changes. Getting an accurate diagnosis of thyroid eye disease can be challenging, especially if you have mild symptoms.

Diagnosing and Monitoring Thyroid Eye Disease

The Role of an Ophthalmologist and Endocrinologist

Not all doctors have experience in treating thyroid eye disease, which is a complex and rare condition. An ophthalmologist (eye specialist) is likely to have the most experience with TED. This may be an oculoplastic surgeon, neuro-ophthalmologist, or strabismus surgeon. These specialized eye doctors:

• Repair physical damage to the eye (oculoplastic surgeons)

• Treat vision problems related to the nerves (neuro-ophthalmologists)

• Perform eye muscle surgery (strabismus surgeons)

They are trained to perform eye surgery but also see patients in the active phase of TED before surgery is recommended.

Important Diagnostic Tests: Imaging and Thyroid Hormone Levels Assessment

A comprehensive evaluation for thyroid eye disease (TED) includes:

• A detailed medical history where your healthcare provider reviews your symptoms and concerns as well as any pre-existing health issues.

• A physical exam to evaluate your eyes and assess the severity of your symptoms. This may include: 

  • Visual acuity testing to test your vision.

  • Visual field testing to identify blind spots.

  • Color vision testing to evaluate how you see different colors.

  • Measurement of eye bulging with a noninvasive instrument called a Hertel exophthalmometer.

• Imaging studies such as fundus photography, magnetic resonance imaging (MRI), and computed tomography (CT). These studies help to rule out other eye conditions and identify complications such as damage to the optic nerve (compressive optic neuropathy).

• Laboratory tests, including thyroid function and thyroid antibodies.

Monitoring Progress and Identifying the Active Phase

If you have a thyroid disorder, your healthcare provider will routinely screen you for early signs of thyroid eye disease. If you have asymptomatic Graves’ disease or mild thyroid eye disease, regular follow-ups can help with prompt diagnosis of the active phase and treatment to prevent sight-threatening complications.

Treatment and Management of Thyroid Eye Disease

Eyedrops

TED patients commonly experience dry eyes and eye pain due to inflammation. Your doctor may prescribe artificial tears and lubricating eye gels to relieve dryness. They may also give you anti-inflammatory eye drops to control swelling and redness.

Selenium

People with mild active TED may benefit from taking selenium supplements twice a day for 6 months. Selenium is a natural mineral that helps to reduce inflammatory symptoms. 

Correction of Thyroid Dysfunction

Stabilizing fluctuating thyroid levels and getting them in the normal range is an important part of treatment for thyroid eye disease. Thyroid dysfunction can be treated with: 

• Antithyroid medications to reduce the production of thyroid hormone in people with hyperthyroidism (Graves’ disease).

• Radioactive iodine therapy to destroy overactive thyroid cells in hyperthyroidism.

• Surgical removal of the thyroid gland in hyperthyroidism.

• Thyroid hormone replacement therapy in people with hypothyroidism (underactive thyroid).

Corticosteroids

Corticosteroids suppress the immune system and reduce inflammation in the eyes. These medications can help with TED symptoms such as eye pain, redness, and swelling. Generally, intravenous (IV, into the vein) methylprednisolone is administered weekly for 12 weeks. In severe active cases, oral steroids are used for six months.

Teprotumumab (Tepezza)

The U.S. Food and Drug Administration (FDA) approved teprotumumab (Tepezza) as the treatment for moderate to severe thyroid eye disease. It is a monoclonal antibody that acts against the insulin-like growth factor-1 receptor (IGF-1R), stopping the body’s inflammatory response. The treatment is given by IV infusion every 3 weeks for a total of 8 treatments. Tepezza can help reduce double vision (diplopia), eye bulging (proptosis), and eye inflammation. 

Tocilizumab (Actemra)

Tocilizumab (Actemra) is also an immune response inhibitor that can help to reduce inflammation in the eye tissues. It is a monoclonal antibody that works against the interleukin-6 receptor. It is used to treat other autoimmune diseases, such as rheumatoid arthritis, and may help people with moderate to severe TED in the active phase. Actemra is given by monthly IV infusion for at least 4 months.

Radiation Therapy

In some cases, a combination of corticosteroids and orbital radiotherapy can result in more effective treatment of eye inflammation. This may be offered to people with moderate or severe active TED.

Surgery for Thyroid Eye Disease

• Orbital Decompression Surgery: This surgery may be offered when TED is in the stable stage. It is done to treat eye bulging by removing excess fat or bone and repositioning the eyeball in the eye socket.

• Strabismus surgery: These procedures are done to loosen or tighten eye muscles and correct double vision.

• Eyelid surgery: Also called retraction repair or blepharoplasty, it is done to reposition the eyelids. This aids the normal opening and closing of the eyes. Excess fat and skin can be removed to make more space and restore vision. The procedure can also give the eyelids a more natural appearance.  

Lifestyle Adjustments and Management Strategies

Smoking Cessation

Smoking is a major risk factor for thyroid eye disease and can complicate the treatment of this condition. Work with your doctor to develop a plan to quit smoking if you smoke and have early symptoms of TED. Research-based therapies for smoking cessation include psychotherapy counseling sessions, mindfulness skills coaching, nicotine replacement therapies, and support groups.

Support Groups

Thyroid eye disease can cause changes in facial appearance, which can lead to emotional distress. This may cause mood swings, anxiety, and depression. Therefore, TED patients may need to see a psychologist for mental health concerns related to the condition. 

The Importance of Regular Follow-Up and Monitoring

It’s important to follow your doctor’s recommended treatment plan carefully. Treatment for thyroid eye disease is tailored based on the severity of the disease and your health history. Keep all your medical and laboratory appointments during treatment for thyroid eye disease. Regular follow-ups can help with prompt diagnosis and treatment of any new symptoms or complications and prevent vision loss.

Comparing Thyroid Eye Disease to Other Thyroid Disorders

Thyroid eye disease (TED) is a rare, complex, inflammatory, autoimmune eye disorder. It can be challenging to diagnose and treat. TED involves many different parts of the eye, including the eye muscle, nerves, fat, connective tissue, blood vessels, and optic nerve. Fluctuating thyroid levels can unpredictably affect the clinical course of TED.

Similarities and Differences Compared to Other Thyroid-Related Conditions

Both Graves' disease and thyroid eye disease are autoimmune conditions. However, in Graves’ disease, the immune system attacks cells in the thyroid gland. In thyroid eye disease, the immune system attacks tissue in and around the eyes. Many people with Graves' disease often develop TED, which can cause confusion between the two conditions. However, you can have Graves’ disease and never develop TED. You can also have TED without having Graves’ disease.

The Impact of Autoimmune Thyroid Diseases on Eye Health

Hashimoto’s thyroiditis, which is an autoimmune disease, is a common cause of hypothyroidism (underactive thyroid). Hypothyroidism does not typically cause problems with eye health. However, people with severe hypothyroidism may have symptoms like eye swelling and loss of hair in the outer eyebrows.

Eye problems are more common in people with hyperthyroidism (overactive thyroid), particularly Graves' disease. Graves’ disease is an autoimmune condition and is a common type of hyperthyroidism. Also, thyroid eye disease or Graves' orbitopathy, which is an autoimmune condition, can develop in people with Graves’ disease. It can cause symptoms such as eye inflammation, eyeball bulge, and vision changes.

Learn more about the difference between an underactive thyroid and an overactive thyroid.