What Is Thyroid Eye Disease?
Learn what thyroid eye disease is, how it affects the eyes, common symptoms, risk factors, and when patients should seek an eye examination.
What Is Thyroid Eye Disease?
Thyroid Eye Disease (TED) is an autoimmune condition that affects the tissues surrounding the eyes. It is most commonly associated with Graves’ disease, but eye disease can occasionally occur in people whose thyroid hormone levels are normal or low.
TED can cause dry or irritated eyes, eyelid swelling, changes in the position of the eyelids, bulging of the eyes, double vision, and changes in vision. Understanding the condition and recognizing changes early can help patients receive appropriate evaluation and treatment.
How Does Thyroid Eye Disease Affect the Eyes?
The eye sits inside a bony structure called the orbit, or eye socket. The muscles, nerves, blood vessels, and fatty tissues surrounding the eye normally fit within this confined space.
With TED, inflammation can cause some of these tissues to become swollen or enlarged.
This may lead to:
- Eyelid swelling or puffiness
- Eyelids that appear more open than usual
- Difficulty completely closing the eyes
- Redness or irritation
- Dryness or excessive tearing
- A gritty or sandy sensation
- Sensitivity to light
- Bulging or forward movement of the eyes
- Difficulty moving the eyes normally
- Double vision
- Eye discomfort or pressure
- Blurred or reduced vision in more serious cases
The severity and combination of symptoms vary considerably from person to person.
What Causes Thyroid Eye Disease?
TED results from an abnormal immune response. It is most commonly associated with Graves’ disease, another autoimmune condition in which the immune system affects the thyroid gland.
The same underlying autoimmune process can affect tissues around the eyes.
TED may occur before, at the same time as, or after a thyroid disorder is diagnosed. Although it is most strongly associated with an overactive thyroid caused by Graves’ disease, TED can occasionally occur in people with normal or underactive thyroid function.
Who Is More Likely to Develop TED?
Several factors can influence the risk of developing TED or having existing eye disease become worse.
Smoking
Cigarette smoking is one of the most important modifiable risk factors associated with TED. Exposure to cigarette smoke, including secondhand smoke, can increase the risk of worsening eye disease.
For people with TED, avoiding tobacco smoke is an important part of disease management.
Abnormal Thyroid Hormone Levels
Both overactive and underactive thyroid states can be associated with worsening thyroid eye disease.
Working with the appropriate medical professional to maintain thyroid hormone levels within the recommended range is therefore an important part of overall care.
Graves’ Disease
TED is most commonly associated with Graves’ disease. However, the severity of the thyroid disorder does not always directly predict the severity of the eye disease.
This is one reason why the eyes need to be evaluated separately when symptoms develop.
Radioactive Iodine Treatment
Radioactive iodine, which can be used to treat Graves’ hyperthyroidism, has been associated with worsening of TED in some patients, particularly those with existing risk factors.
The decision about how to treat the thyroid should therefore take the patient’s eye disease into account. This is a discussion that should involve the appropriate thyroid and eye-care professionals.
What Are the Symptoms of Thyroid Eye Disease?
Symptoms can range from mild irritation to significant changes in eye appearance, movement, and vision.
Common symptoms include:
- Dry or gritty eyes
- Red eyes
- Watery eyes
- Puffy eyelids
- Eyelid retraction, where the eyelids sit higher or lower than usual
- Sensitivity to light
- A feeling of pressure around the eyes
- Bulging eyes
- Difficulty closing the eyes completely
- Double vision
- Changes in eye movement
- Blurred vision
Not everyone experiences all of these symptoms, and symptoms can affect one or both eyes.
Frequently Asked Questions
Can Thyroid Eye Disease Change Over Time?
Yes. TED often has an active phase, during which inflammation and swelling are more prominent, followed by a period in which the disease becomes less active.
The transition does not necessarily mean that every eye change disappears. Some people are left with persistent eyelid changes, eye prominence, double vision, or other effects even after the active inflammation has settled.
This distinction between active disease and inactive residual changes is important because the appropriate treatment can be different at different stages.
Can Thyroid Eye Disease Affect Vision?
Many people with TED have mild disease and do not experience serious vision loss.
However, more severe disease can affect the cornea or place pressure on the optic nerve. The optic nerve carries visual information from the eye to the brain.
When the optic nerve becomes compressed, vision can be threatened. This is an ocular emergency requiring prompt assessment and treatment.
What Are the Warning Signs That Need Prompt Attention
Seek urgent eye-care assessment if you develop:
- A sudden or significant reduction in vision
- New or worsening loss of color vision
- Significant deterioration in vision in one or both eyes
- Severe eye pain or rapidly worsening symptoms
- Inability to close the eye with significant exposure or corneal symptoms
- Rapidly worsening double vision accompanied by other significant changes
These symptoms do not necessarily mean that TED is causing a sight-threatening complication, but they should not be ignored.
When Should You Be Evaluated for TED?
Anyone with thyroid disease who develops new eye symptoms should discuss them with a healthcare professional.
An eye examination is particularly important if you notice:
- New eye bulging
- Persistent redness or irritation
- New double vision
- Changes in eyelid position
- Difficulty closing your eyes
- Changes in vision
- Increasing discomfort around the eyes
Early evaluation can help determine whether the symptoms are related to TED and whether the disease appears active or inactive.
Continue Learning
Thyroid Eye Disease: Diagnosis & Treatment
Learn how doctors evaluate TED, determine its severity and activity, and choose among available treatment options.
Living With Thyroid Eye Disease: Symptoms, Surgery & Long-Term Care
Learn about managing persistent symptoms, surgical options, and long-term monitoring.
Medical Disclaimer
The information on this page is provided for general educational purposes and is not a substitute for a professional eye examination, diagnosis, or individualized medical advice. Cataract treatment and surgical decisions depend on each patient’s eye health, medical history, visual needs, and other individual factors. If you have sudden or significant changes in vision, severe eye pain, or other concerning symptoms, seek prompt medical attention.
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