A frustrating complication associated with autoimmune thyroid disorders is thyroid eye disease (TED). Thyroid eye disease tends to strike people with Graves’-related hyperthyroidism and sometimes even those suffering from Hashimoto’s disease.
In clinical circles, TED is known by several different names: Graves’ ophthalmopathy (GO), thyroid-associated ophthalmopathy, and, infrequently, dysthyroid orbitopathy. (The pre? x ophthalmo- means “eyes,” while -pathy means “disease.”) This disease is characterized by bulging, watery eyes, a condition known as exophthalmos.
A common symptom of excessive thyroid hormone is lid retraction. Here, your upper eyelids can retract slightly and expose more of the whites of your eyes. The lid retraction creates a rather dramatic staring look. This speci? c symptom is related to the excessive activation of the adrenaline system from thyrotoxicosis and can be seen in nonautoimmune thyrotoxicosis. It will improve with beta-blockers.
It’s different from the actual bulging of the eyes, called proptosis, which only occurs in autoimmune thyroid disease. The lid retraction will usually improve when the hyperthyroidism is treated. This is not always the case with proptosis, as many people also have bulging of their eyeballs from underlying TED, which seems to persist long after the hyperthyroidism ends.
When TED is associated with the hyperthyroidism of Graves’ disease, the eye problems can be far more severe. At least 50 percent of all Graves’ disease patients suffer from obvious TED. At one time, only those with noticeable changes to the eyes were considered to have TED, but more sophisticated methods of diagnosis reveal that eye changes are present in almost all Graves’ disease patients, even though symptoms may not be noticeable.
It is believed that the autoimmune antibodies that develop in Graves’ disease cause TED. For some reason, the same proteins in your thyroid cells and your eye muscle cells react to the antithyroid antibodies that occur with Graves’ disease. Treatment of the thyroid does not usually help the eyes, which continues to frustrate TED sufferers.
Smoking and Thyroid Eye Disease
Smokers are far more likely to suffer from severe TED than nonsmokers, although stress seems to aggravate the condition, too. As for smoking, the link between smoking and thyroid eye disease is so strong that thyroid specialists believe smokers with Graves’ disease can probably count on developing TED. The following facts are known about smoking and Graves’ disease:
• Smoking worsens the course of Graves’ disease and its severity.
• Smoking increases the likelihood that a person with Graves’ disease will have signi?cant TED.
• People with such severe TED that they need steroid treatments or radiation treatment to their eyes will not respond as well to these treatments if they smoke.
• Ex-smokers do not have such risk for the development and worsening of their Graves’ disease, suggesting a value to stopping any smoking as soon as possible.
The Symptoms of Thyroid Eye Disease
The most common eye changes caused by TED are bulging and double vision. These symptoms are caused by in? ammation of the eye tissues: the eyes become painful, red, and watery with a gritty feeling. Sensitivity to light, wind, or sun is also common. The grittiness and light sensitivity worsen with lid retraction, as the eyes are less protected by the eyelids from dust, wind, and infection.
Other symptoms include discomfort when looking up or to the side. And while some Graves’ disease patients suffer from excessive watering of the eyes, many also suffer from excessive dryness. In rare and extreme cases, vision deteriorates as a result of too much pressure being placed on the optic nerve from the protruding eyeball.
The covering of the eye also becomes in?amed and swollen. The eyelids and the tissues around the eyes are swollen with ?uid, and the eyeballs tend to bulge out of their sockets. Because of eye muscle damage or thickening, the eyes cannot move normally, resulting in blurred or double vision.
Interestingly, some people notice that TED symptoms worsen when their thyroid hormone levels are lower than normal. Because hypothyroidism causes bloating and ? uid retention, this can exacerbate in?ammation of the eyes, triggering TED symptoms such as dryness and grittiness. Many thyroid patients have ongoing disputes with their physicians over whether their TED ?are-up is related to their thyroid condition. It may be. Since much is unknown about the relationship between TED and thyroid hormone levels, you do not have to accept your doctor’s word.
During what’s called the hot phase, or the initial active phase of TED, in?ammation and swelling around and behind the eye are common. This phase lasts about six months, followed by the cold phase, in which the in?ammation subsides and the visual changes are more noticeable.
In severe cases the swelling may be so bad that you will ? nd it dif?cult to move your eye, and you may even develop ulcers on the cornea. This comes from constant exposure to the air because the eye is so swollen that the lids can’t close to distribute the lubricating tears. In most cases both eyes are affected, but one may be worse than the other. You may also experience a phenomenon called lid lag, in which your upper lids are slow to move when you’re looking down.
Lid lag results from the effects of too much thyroid hormone and will go away if your thyroid hormone levels are lowered or you are treated with a beta-blocker medication.
Generally, the changes to the eyes reach a burnout period within a two-year time frame and then stop. Severe cases of TED can progress to blindness, even with proper intervention, but this is very rare.
Sometimes the eyes get better by themselves, but often, after the burnout period, the eyes remain changed but do not get any worse. An ophthalmologist can measure the severity of the eye changes with an instrument called an exophthalmometer, which measures the degree to which the eyes protrude from the skull.
Treating Thyroid Eye Disease
You cannot treat TED if you don’t know you have TED. In some cases, the eye symptoms may precede other signs of thyroid disease. In other cases, the eye symptoms may not appear until long after the thyroid disease is treated. So it is important to recognize that the symptoms of TED are related to thyroid disease in the ? rst place before any effective treatments for TED can be planned. In cases where the eye symptoms appear before any signs of thyroid disease, a good doctor will try to discover reasons for the symptoms, and exclude other causes, such as tumors in the eye socket, which would be evaluated with an MRI or a CT scan. In some cases, when the hyperthyroidism is treated, the eyes tend to get better—even before burnout occurs.
And TED in the absence of hyperthyroidism tends to be much easier to treat. If hyperthyroidism is treated with radioactive iodine, it may make TED worse.
The ? rst step in treating TED is using arti? cial tears during the day and lubricating ointment at bedtime. If TED becomes worse, the next step is to prescribe prednisone, a steroid, which reduces swelling and in? ammation causing the more severe TED symptoms. Steroids have numerous side effects, however, and you’ll need to make an informed decision in balancing these side effects against the TED symptoms. The other problem with steroids is that once you go off of them, TED symptoms can resume and may even get worse.
If you choose not to go on steroids, you can have radiation therapy, or you may be a candidate for a surgical procedure known as orbital decompression surgery. These treatments are very involved, beyond what can be covered here. Your doctor can help you determine if these options might be a good choice for you.