Thyroid Eye Disease

The eye changes associated with thyroid disease are referred to as Thyroid Eye Disease (TED). Although TED is seen in all types of thyroid disorders, it is most common in patients that are or were hyperthyroid. It also rarely occurs in those who are hypothyroid and even when there is an absence of thyroid abnormalities in the body.

Thyroid disease can cause multiple eye problems. These include redness and swelling, double vision, decreased vision, eyelid retraction (inability to close the eyes), and a bulging of the eye itself. It is important to realize that if one of these occurs, it does not mean you will necessarily get all the other symptoms too.

Eye problems will usually occur and frequently change in type or severity for between six months and two years. Once stabilized, it is unusual for the eyes to start changing again. Some patients are left with permanent changes, and others return to normal. A great deal can be done to improve these conditions with medical treatment, although some patients will need surgery to address their issues.

What causes thyroid eye disease?

TED is usually associated with systemic (generalized) hyperthyroidism or Graves' disease. This disease is caused by what is described as an autoimmune process. Autoimmune disease may be understood as a process by which the body sees some part of itself as being foreign and reacts to it much the same way that it would to any bacteria or virus.

In the case of Graves' disease, the body sees the thyroid gland as a foreign object and produces antibodies that attack the thyroid gland. This often causes the thyroid gland to become overactive.

The eye version of this disease is called Thyroid Eye Disease (TED). However, in the case of TED, different antibodies attack the muscles associated with eye and eyelid movement. Although the thyroid gland and the eye may be under attack by the same immune system, it is felt that both conditions remain mostly independent of one another. The antibodies that attack the eye can cause inflammation and swelling of the fat and muscles around the eye, which is what can eventually cause bulging of the eyes, double vision, and retraction of the eyelids.

Will my eyes go back to normal after treatment?

Most patients believe that once their medical doctor treats the body's thyroid problem the eyes will go back to normal. This is often not the case. In some patients, the eyes worsen in the months and years after medical treatment despite the body being stabilized. Even though good medical treatment may not prevent or cure TED, it is extremely important to treat the thyroid abnormality and keep your body in proper thyroid balance.

The eye specialist's role

Your specialist can provide simple solutions to the irritation, tearing, and swelling often associated with TED. Often, this involves something as simple as using artificial tears during the day and lubrication ointment at night. Your specialist can determine when your eyes have stopped changing and whether corrective surgery is needed. Your specialist may also watch for the rare serious problems associated with TED that need prompt treatment.

New treatments for TED

The drug TEPEZZA was considered a breakthrough in therapy by the FDA and is the first and only approved therapy for TED in the US in 2020. Tepezza binds to the IGF-1R and blocks the increased production of molecules for fibrosis. It is a targeted treatment, which is why it is well tolerated. It reduces eye bulging and double vision in patients with TED no matter how long they have had the disease. Research from multiple international clinical trials has clearly shown its effectiveness. In addition, it reverses double vision and the facial changes associated with the disease. As with any medication, it can have side effects but these mostly appear to be temporary and occur infrequently. In one study, 98% of patients were pleased with treatment.

Problems associated with thyroid eye disease

Dry irritated eyes 

TED may cause you to experience dry, irritated, and teary eyes. This is usually due to the eyelids retracting and/or eye protruding. When the eyelids do not close completely at night, the cornea (clear front portion of the eye) dries out and becomes quite uncomfortable. The use of lubricating ointment for the eye at night and artificial tears during the day can provide relief. Do not be afraid to use preservative-free tears frequently, as much as every 1/2 to 1 hour if necessary.

Double vision

TED can cause swelling, irritation, and scarring of the muscles that move the eyes. This can lead to double vision. Double vision may not be present all the time, sometimes it is noticeable only when looking in certain directions, while in other patients, it is always present. Often the amount of double vision will change week to week. At times, it can disappear completely without treatment. Once the double vision has been stable for at least several months, surgery can be performed if necessary. Your oculofacial surgeon will refer you to an eye muscle specialist (or strabismus surgeon) for the surgery.

Eyelid retraction

TED can cause scarring in the eyelid muscles. This scar tissue contracts or shortens, causing the eyelid to retract and increasing the white showing above and below the colored part of the eye. The amount of retraction tends to be variable, often changing from week to week. In some patients, the retraction will disappear with time. In addition to contributing to an unusual appearance of the eyes, eyelid retraction can cause significant dryness, irritation, and tearing. Light sensitivity is another common complaint. Severe drying of the front of the eye can occasionally lead to vision loss.

It is usually preferred to wait for the eyelid position to stop changing before proceeding with surgery. Surgery involves moving the eyelids into a more “normal” position. In the upper eyelids, this is usually performed by removing or stretching the scarred muscles. In the lower eyelids, a graft is often needed to help push the eyelid upward. Eyelid repositioning can make a tremendous difference in both the feel and appearance of the eyes.

Eye protrusion

TED can cause an accumulation of fluid in the fat and muscles around and behind the eye. This can push the eye itself outward making it much more prominent (or proptotic). Coupled with eyelid retraction, this proptosis can alter the appearance and comfort of the eye. Although less variable than eyelid retraction, the protrusion of the eye also known as proptosis can return to normal on its own. After being stable for several months or more, it is sometimes desirable to surgically move the eye into a more “normal” position. This can be accomplished by removing a portion of the bones surrounding the eye. The swollen fat and muscles around the eye can then fall into the extra space, allowing the eye to move backward. This helps the eyes to return to their pre-thyroid appearance and relieves the relentless pressure and irritation most patients feel around their eyes.

Vision loss

Decreased vision can occur in TED for several reasons. Exposure and irritation of the cornea (clear front portion of the eye) occurs secondary to eyelid retraction and eye protrusion/proptosis. Drops, ointment, eyelid repositioning, or eye repositioning may be needed depending on the patient’s needs to improve vision. The other cause of decreased vision, but more rare, is compression of the main nerve from the eye to the brain. This occurs behind the eye when the muscles that move the eye become extremely swollen and press on the optic nerve. If your vision decreases significantly, bring this to the doctor’s attention promptly. Often, medications taken by mouth will return vision to normal. Surgery and/or radiation treatments are occasionally necessary to restore vision.

Cosmetic considerations

Many people with TED have eyes that appear to have prematurely aged. Swelling of the eyelids is one of the reasons for this. Additionally, a fluid accumulation in the normal fat around the eyes causes this fat to bulge outward becoming visible as "bags" of the eyelids. If this does not go away on its own, it can be surgically removed. 

Although thyroid disease can cause multiple problems with the eyes, there are many options to help with these issues. Once your eyes have stabilized, we can plan a course of treatment to correct the problems you find to be most troublesome. It will often be necessary to come to the office several times over many months, so we can measure and examine your eyes. Bring old photographs that show your face when you were younger and before you developed thyroid eye disease. These can be useful during your initial office visit. Photographs from before your eyes were affected by the thyroid condition and more recent ones that show how long your eyes have looked abnormal are very helpful. Together, with patience and perseverance, our surgeons can do a lot to improve comfort and return your eyes to a more normal appearance.