Endocrine Ophthalmopathy

Thyroid Eye Disease, Graves’ ophthalmopathy, Graves’ orbitopathy, Graves’ eye disease, thyroid-associated orbitopathy, thyroid-associated ophthalmopathy, TED, thyroid ophthalmopathy

Endocrine ophthalmopathy is an autoimmune condition that affects the tissues around the eyes, causing swelling, inflammation, and sometimes bulging of the eyes. It most commonly occurs in people with Graves’ disease, an overactive thyroid condition, though it can also develop in people with normal or underactive thyroid function.

Table of contents

• What is Endocrine Ophthalmopathy?
• Connection to Thyroid Disease
• Who is Affected?
• Signs and Symptoms
• What Causes This Condition?
• Risk Factors
• How is it Diagnosed?
• Treatment Options
• Living with Endocrine Ophthalmopathy
• Possible Complications

What is Endocrine Ophthalmopathy?

Endocrine ophthalmopathy is an autoimmune disease that affects the tissues, muscles, and fat around the eyes. An autoimmune disease occurs when the body’s immune system mistakenly attacks its own healthy tissues^[1]. In this condition, the immune system causes inflammation and swelling in the area behind the eyeballs, which can lead to the eyes bulging forward, a condition called proptosis^[4].

This eye disease is the most common problem affecting areas outside the thyroid gland in people with Graves’ disease, though it can occur in people with other thyroid conditions or even in those with normal thyroid function^[3]. The condition usually affects both eyes, although the severity can differ between them^[1].

The disease typically has an active phase that lasts about nine to twelve months, during which inflammation and symptoms are most noticeable. After this period, the condition usually becomes stable, though some changes may be permanent^[4].

Connection to Thyroid Disease

About 90% of people with endocrine ophthalmopathy have hyperthyroidism, which is when the thyroid gland produces too much thyroid hormone^[1]. The most common cause is Graves’ disease, where the immune system attacks the thyroid gland, causing it to become overactive^[3].

The connection between the thyroid and the eyes happens because certain receptors, called thyroid-stimulating hormone (TSH) receptors, exist both in the thyroid gland and in the tissues around the eyes. When the immune system creates antibodies that attack these receptors, both the thyroid and the eye tissues can be affected^[1].

While most cases occur with hyperthyroidism, about 10% of people with endocrine ophthalmopathy have an underactive thyroid (hypothyroidism), often due to Hashimoto’s thyroiditis, and another 10% have normal thyroid function at the time of diagnosis^[3]. The eye changes can appear before, at the same time as, or after thyroid disease is diagnosed^[1].

Keeping thyroid hormone levels stable is important for managing eye symptoms. Fluctuations in thyroid hormone levels, whether too high or too low, can make the eye condition worse during its active phase^[1].

Who is Affected?

Approximately one-third of people with Graves’ disease develop some signs or symptoms of endocrine ophthalmopathy, though only about 5% experience moderate to severe disease^[1]. The annual rate of new cases is estimated at about 16 per 100,000 women and 2.9 per 100,000 men in some communities^[4].

Women are affected much more frequently than men, being five to six times more likely to develop the condition^[3][6]. However, when men do develop endocrine ophthalmopathy, they tend to have more severe cases^[4].

The condition most commonly appears in people between the ages of 30 and 50, though it can occur at any age^[3]. Severe cases are more frequent in people older than 50 years^[4].

Signs and Symptoms

Most people who develop endocrine ophthalmopathy experience one or more of several characteristic symptoms. The severity can range from mild discomfort to more serious vision problems^[2].

Common symptoms include:

• Dry, itchy, or irritated eyes that feel gritty, as if sand is in them^[2][5]
• Red, bloodshot eyes due to swelling and inflammation^[2]
• Watery or teary eyes^[5]
• Sensitivity to light^[5]
• Swollen and puffy eyelids^[2]
• Bulging eyes (proptosis), which can give a staring appearance^[2][3]
• Pain behind the eyes or when moving the eyes^[5]
• Difficulty moving the eyes or closing them completely^[5]
• Double vision, especially when looking to the sides^[2][5]
• Blurred vision^[13]

These symptoms normally affect both eyes, though sometimes they may be noticed in only one eye initially^[13]. The symptoms can come and go and may range from mild to severe^[13].

What Causes This Condition?

Endocrine ophthalmopathy is caused by an abnormal immune response where the body’s defense system mistakenly attacks healthy tissues in the eye area^[6]. The exact cause is not completely understood, but researchers believe it involves antibodies that target receptors shared by both the thyroid gland and the tissues around the eyes^[3].

In Graves’ disease, the immune system creates antibodies that attach to TSH receptors. While these receptors are mainly found in the thyroid gland, some also exist in the muscles and fatty tissues behind the eyes. When antibodies bind to these eye tissue receptors, they trigger inflammation and swelling^[1][7].

This inflammatory process leads to an increased volume of the muscles that move the eyes (extraocular muscles), as well as the connective tissue and fat in the eye socket^[3]. As these tissues expand, they push the eyeball forward, causing the characteristic bulging appearance.

Risk Factors

Several factors can increase the likelihood of developing endocrine ophthalmopathy or make the condition worse:

Smoking is the most important modifiable risk factor. Smokers are seven times more likely to develop endocrine ophthalmopathy than non-smokers^[6]. Smoking also makes the disease more severe and harder to treat^[5][12]. Exposure to secondhand smoke also increases risk^[13].

Abnormal thyroid hormone levels can contribute to developing or worsening the condition. Both overactive and underactive thyroid states can stimulate the same receptors in eye tissues that the antibodies do^[13].

Radioactive iodine therapy, a standard treatment for hyperthyroidism, may contribute to endocrine ophthalmopathy or make it worse in some cases. Careful monitoring of thyroid hormone levels after this treatment is important, as untreated hypothyroidism can worsen the eye disease^[1][13].

Other risk factors include increased age at the time of diagnosis, longer duration of Graves’ disease, and being female, though males tend to have more severe disease when affected^[4].

How is it Diagnosed?

Endocrine ophthalmopathy is often diagnosed based on the characteristic signs and symptoms, particularly in people who already have or develop Graves’ disease^[6]. Your doctor may perform a physical examination of your eyes and ask about your medical history^[9].

Blood tests are usually performed to check thyroid function and measure thyroid hormone levels. These tests measure thyroid-stimulating hormone (TSH), free T4, and T3 levels. In Graves’ disease, TSH is typically low while thyroid hormone levels are high^[9]. Blood tests can also detect thyroid antibodies, which indicate autoimmune thyroid disease^[6].

If the signs and symptoms are unclear or if only one eye appears affected, imaging tests may be used. A computerised tomography (CT) scan or magnetic resonance imaging (MRI) scan can examine the tissues behind the eyes and show any swelling of the eye muscles or other structures^[6].

To assess how active the disease is and whether it is responding to treatment, doctors may use a clinical activity score. This scoring system includes symptoms that reflect inflammatory changes in the eyes^[3].

Treatment Options

Treatment for endocrine ophthalmopathy depends on how severe the symptoms are and whether the disease is in its active inflammatory phase or has become stable^[3]. The main goals are to control symptoms, reduce inflammation, preserve vision, and improve appearance.

Managing Mild Cases

For mild symptoms, supportive care can often control discomfort and protect the eyes^[3]:

• Using artificial tears (saline eye drops) during the day and eye ointment or gel at night to combat dryness^[5]
• Applying cool, damp compresses over closed eyes to reduce swelling^[14]
• Wearing wraparound sunglasses to protect eyes from wind, sun, and light^[14]
• Elevating the head of the bed at night to help reduce symptoms^[5]
• Using indoor humidifiers to keep air moist and prevent dry eyes^[14]

Medical Treatment for Active Disease

When the disease is severe and active, with significant inflammation, stronger treatments may be needed^[3]:

Corticosteroid medicines are the main treatment for reducing inflammation. These can be given as eye drops for mild cases, as high-dose oral tablets, or through an intravenous (IV) line directly into the bloodstream for more severe cases^[8]. While steroids help with symptoms, they don’t change how long the disease lasts^[12].

Orbital radiotherapy (radiation therapy to the eye socket) may be recommended along with high-dose steroids to reduce disease activity and prevent worsening^[3][12].

Several other treatments have been used for patients who don’t respond to conventional approaches, including immunosuppressive drugs, somatostatin analogs, plasmapheresis (filtering the blood), intravenous immunoglobulins, and newer anticytokine therapies^[3][8].

Surgical Treatment

Surgery may be considered after the disease has become inactive and stable. Different surgical procedures can address specific problems^[3]:

• Orbital decompression surgery removes bone or fat from the eye socket to create more space for swollen tissues and reduce eye bulging^[12]
• Strabismus surgery corrects misalignment of the eyes that causes double vision^[4]
• Eyelid surgery can correct lid retraction and improve the ability to close the eyes^[4]
• Blepharoplasty can improve the appearance of baggy eyelids^[4]

Most people with endocrine ophthalmopathy do not require surgery, as the condition is usually mild and manageable with supportive care^[4].

Managing Thyroid Levels

An essential part of treatment involves working with your doctor to keep thyroid hormone levels in a normal range. This is important because thyroid level imbalances can worsen eye symptoms^[5][12].

Living with Endocrine Ophthalmopathy

Living with endocrine ophthalmopathy requires adapting to vision changes and taking steps to protect your eyes and maintain quality of life.

Protecting Your Eyes

Simple measures can help reduce discomfort and protect your eyes from further damage:

• Use preservative-free artificial tears frequently throughout the day^[14]
• Wear protective eyewear, including wraparound sunglasses outdoors and potentially tinted lenses indoors^[14]
• Avoid environments with smoke, wind, and excessive dryness
• Position computer screens at eye level and use anti-glare filters^[14]

Lifestyle Changes

Quitting smoking is the single most important thing you can do if you smoke. This is the only real modifiable risk factor under your control^[12]. Avoid vaping and secondhand smoke as well^[12].

Eating a healthy, anti-inflammatory diet, such as a Mediterranean diet that focuses on whole foods and avoids processed items, may help reduce inflammation^[12].

Safety at Home

If vision changes affect your daily activities, consider making your home safer:

• Remove tripping hazards and secure rugs and cords^[14]
• Use nightlights in hallways and bathrooms^[14]
• Wear non-slip footwear^[14]
• Use magnifying glasses or screen magnifiers for reading^[14]

Emotional Well-being

The visible changes and discomfort from endocrine ophthalmopathy can lead to anxiety, depression, and withdrawal from social activities. About 20% of affected people say the eye problems are more troublesome than the thyroid disease itself^[4]. Seeking support through counseling, therapy, or support groups can help^[14]. Stress management techniques like meditation, yoga, or deep breathing may also be beneficial^[14].

Possible Complications

Although endocrine ophthalmopathy is usually mild, some people can develop serious complications that require prompt treatment^[4].

Exposure keratopathy can occur if the eyelids cannot close completely due to bulging eyes or lid retraction. This leaves the outer surface of the eyeball (the cornea) exposed to damage from dryness, dirt, and injury, which can harm vision^[4].

Compressive optic neuropathy is a rare but serious complication where swelling behind the eye presses on the optic nerve, the nerve that carries visual information to the brain. This can cause washed-out color vision, reduced vision, and if left untreated, permanent vision loss or blindness^[3][5].

Permanent appearance changes can occur if scarring prevents tissues from healing and returning to their normal shape after the active phase ends. These may include ongoing eyelid retraction, protruding eyes, baggy eyelids, and red eyes^[13].

Vision problems such as blurry vision, double vision, or severe vision loss may persist even after the inflammatory phase has passed^[13]. Surgery can sometimes treat these lasting effects.

Contact your doctor immediately if you notice any change in how you see colors or if parts of your field of vision are lost, as these may signal serious complications requiring urgent treatment^[19].