Thyroid Eye Disease: Symptoms, Causes & Treatment

Thyroid eye disease (TED) is an eye condition characterised by inflammation and damage to the tissues surrounding the eyes, including fatty tissue, muscles, and connective tissue. TED is an autoimmune disorder that progresses through two stages: the active or inflammatory phase, which can last from several months to three years, and the stable phase, where inflammation subsides. This article covers the symptoms, causes, treatment options, and preventive measures for thyroid eye disease.

Symptoms of Thyroid Eye Disease

The symptoms of thyroid eye disease can fluctuate and vary widely. Key symptoms include:

• Eye Protrusion: Swelling of eye muscles can push the eye forward, creating a bulging appearance as if one is constantly staring.
• Eyelid Retraction: The upper and lower eyelids pull back as the eye moves forward, exposing more of the eye’s white area.
• Dryness: Greater exposure to dust and wind causes dryness, making eyes feel uncomfortable, gritty, and often sensitive to light, with blurred vision.
• Vision Changes: Swollen muscles may cause double vision or pressure on the optic nerve, potentially leading to vision impairment.
• Eye Bags: Swelling of the eyelids can lead to under-eye puffiness, giving a baggy appearance that can make one look older.

Seek medical attention promptly if you notice any of the following symptoms:

• A noticeable change in colour brightness, especially if one eye perceives colours as less vibrant than the other.
• Persistent blurred vision that doesn’t improve by blinking or covering an eye.
• Symptoms progressively worsen over several days or weeks.
• Sudden onset of double vision.

Causes of Thyroid Eye Disease

Thyroid eye disease (TED) often appears as part of Graves’ disease, an autoimmune condition that primarily affects the thyroid and sometimes the skin and eyes. The thyroid, a butterfly-shaped gland at the neck's base, controls various bodily functions such as metabolism, heart rate, and temperature. Graves’ disease is marked by thyroid enlargement (goitre) and usually leads to hyperthyroidism, a condition where too much thyroid hormone is produced.Although less common, severe hypothyroidism (insufficient hormone production) can also trigger TED, often resulting in symptoms like eyebrow hair loss and eye inflammation. While TED is usually associated with thyroid dysfunction, it can also occur in people with normal thyroid function, though the exact cause in these cases is not well understood.

Thyroid Eye Disease: Risk Factors

Thyroid eye disease is more common in women than men, primarily because hyperthyroidism is more frequently diagnosed in women. However, men are more likely to have a severe form of the disease. The average age for a TED diagnosis is 43, though it can occur at any age. Certain factors may increase your risk of developing TED, including:

• Low selenium levels in the blood
• A family history of thyroid eye disease
• Smoking
• Radioactive iodine, a treatment for hyperthyroidism or Graves’ disease, may worsen active TED unless combined with steroid therapy to mitigate its effects.

How is Thyroid Eye Disease Diagnosed?

Thyroid eye disease can be diagnosed by a primary care physician, an ophthalmologist, or an endocrinologist. TED is often challenging to identify, as patients may initially be misdiagnosed and treated for conditions like allergies, conjunctivitis, or hay fever for several months before receiving an accurate diagnosis. Symptoms like sticky or itchy eyes are uncommon in TED. Possible indicators that your symptoms may be due to TED include:

• Eye discomfort or pain, especially when moving the eyes.
• Symptoms outside typical allergy seasons.
• Onset of double vision, a serious symptom often associated with TED.

A healthcare provider can diagnose thyroid eye disease through a physical eye examination. This assessment typically involves measuring the extent of eye bulging and conducting tests to evaluate your visual field and colour vision. They will also closely examine both your eyelids and eyes. If TED is suspected, blood tests to check thyroid hormone levels and antibodies may be recommended. Additional tests that might be ordered include:

• Computed tomography (CT) scan
• Eye ultrasound
• Magnetic resonance imaging (MRI)

Treatment Options for Thyroid Eye Disease

If you are diagnosed with thyroid disease, your provider will likely begin by addressing that condition, though treating thyroid disease alone does not resolve thyroid eye disease (TED). For TED, they may recommend several therapies, including:

Over-the-counter medications

• Lubricating eye drops to ease irritation and dryness, which are generally available without a prescription. Avoid drops intended to reduce redness.
• Additionally, if selenium levels are low, your provider might advise selenium supplements.
• Some studies have also shown that drinking aloe vera juice can help reduce inflammation in certain cases.

Prescription medications 

For treating thyroid eye disease (TED), your provider may prescribe medications such as anti-inflammatory drugs like prednisone, other systemic steroids, or rituximab. It’s important to discuss the potential side effects of these treatments with your provider. A newer medication specifically for TED, called teprotumumab, may also be recommended.

Home Remedies and Lifestyle Changes

 Making certain lifestyle changes and trying home remedies can help manage thyroid eye disease (TED). The most crucial change is quitting smoking, as it significantly increases the risk of developing TED and prolongs the active (inflammatory) phase. Smoking also reduces the effectiveness of TED treatments. Other strategies for comfort include:

• Wearing sunglasses to protect your eyes.
• Applying cool compresses to your eyes.
• Keeping your head elevated above your body while lying down.
• Taping your eyelids shut during sleep to prevent dryness and corneal ulcers, which can cause scarring and vision loss.
• Taking selenium supplements (with your doctor’s approval), as they may benefit those with mild active TED.
• Using glasses with prisms to alleviate double vision.
• Maintaining balanced thyroid hormone levels by following your doctor’s recommendations and getting regular thyroid tests.
• Wearing an eye patch to reduce double vision.

Surgery

Surgery may be recommended to treat thyroid eye disease in certain cases:

• Eyelid Surgery: This procedure helps correct tight eyelids that prevent proper eyelid movement, which can cause corneal damage. Eyelid surgery can make it easier to keep the cornea properly covered.
• Orbital Decompression Surgery: This surgery reduces pressure on the optic nerve by enlarging the eye socket or removing excess tissue, which helps decrease eye bulging. If eyelid or eye muscle surgeries are also recommended, orbital decompression is typically performed first.
• Eye Muscle Surgery: If double vision is an issue, your provider may suggest surgery to adjust the position of your eye muscles. Multiple surgeries may be required to achieve the desired outcome.

Can Thyroid Eye Disease Be Prevented?

Thyroid eye disease cannot be prevented, but there are steps you can take to manage the condition and prevent it from worsening:

• Quit Smoking: If you smoke, seek help to quit. Smoking worsens the effectiveness of TED treatments, but this effect usually reverses after quitting. Non-smokers and former smokers have a better chance of recovering from thyroid overactivity with treatments like Carbimazole or Propylthiouracil compared to smokers. While the impact of vaping on TED is not well-researched, quitting both smoking and vaping benefits TED management and overall health.
• Maintain Stable Thyroid Levels: Fluctuations in thyroid levels, especially hypothyroidism, can worsen TED. Regular thyroid tests and following your doctor’s instructions on thyroid medication are essential to keep your thyroid levels steady, improving the chances of eye healing and overall well-being.
• Avoid Radioiodine Treatment If You Have Active TED: Radioiodine therapy can exacerbate TED, particularly in smokers. Consult your doctor to determine if special precautions are needed or if treatment should be postponed.
• Consider Selenium Supplements: Selenium supplements may benefit patients with mild active TED. These supplements are available over the counter.

Conclusion

Thyroid eye disease is a complex condition that affects the tissues around the eyes, often linked to thyroid disorders like Graves' disease. While TED cannot be prevented, you can manage the disease and minimise its impact by taking steps such as quitting smoking, maintaining stable thyroid hormone levels, and considering selenium supplements. Treatment options such as medication, lifestyle changes, and in some cases, surgery, can provide relief and improve quality of life for individuals living with TED. Early diagnosis and consistent management are crucial for controlling symptoms and preventing further complications. Always consult with your healthcare provider for personalised treatment and guidance tailored to your needs.