THYROID EYE DISORDERS
WHAT ARE THE THYROID GLAND DISEASES?
The thyroid gland is located in the neck and produces hormones that help regulate our metabolism. When there is an excess of thyroid hormones, it is known as hyperthyroidism. When it produces too little, it is called hypothyroidism.
Imbalance in the production of thyroid hormones can cause eye and vision problems. Symptoms of hyperthyroidism include fatigue, tachycardia (fast heartbeat), weight loss, sweating, diarrhea, strong perspiration and fine hair. Hypothyroidism may also cause fatigue, but with bradycardia (slow heartbeat), constipation and weight gain.
WHAT ARE THE SYMPTOMS OF THYROID-RELATED EYE PROBLEMS?
Protruding eyes (a bug-eyed appearance) and conjunctival dryness are often the first symptoms. Early signs include swelling of the eyelids and the periorbital tissue. Swelling of the tissue surrounding the eye can push the eye outward, creating the appearance of protruding or "bulging eye".
The degree of eye protrusion is variable and can involve one or both eyes. Also, thickening of muscles responsible of the eye movement may happen. As a result, double vision or diplopia may appear.
In severe cases, the cornea may ulcerate and the optic nerve may be damaged resulting in permanent loss of vision.
CAN THYROID EYE DISEASE HAPPEN EVEN IF THYROID FUNCTION TESTS ARE NORMAL?
Yes. Eye protrusion and other symptoms of thyroid eye disease may be present even when these tests show normal levels of thyroid hormone in the blood (called euthyroid).
However, most patients with eye symptoms have abnormal blood levels of thyroid hormone.
WHAT IS THE TREATMENT FOR THE THYROID EYE DESEASE?
Once an overactive thyroid gland is suspected, the thyroid activity must be evaluated and a therapeutic strategy must be found accordingly. Eye disease may continue to progress even after treating and returning hormone levels to normal. Therefore, the ophthalmologist should follow and treat the eyes, if necessary.
Two different phases of eye treatment should be considered. The first one involves the treatment of the active eye disease. The active period lasts two years or more and requires careful monitoring until stabilization.
The second phase involves correcting the changes that appear after the active phase and are usually those that last longer and make the resolution more difficult.
Treatment during the active phase of the disease focuses on preserving vision. The treatment involves the administration of artificial tears and ointments, occasionally high doses of cortisone and, in severe cases, orbital surgery and radiotherapy. In the second phase, treatment of permanent changes may require surgical correction of diplopia, staring appearance or eye protrusion.
WHY ARE IMPORTANT EYE CHECKUPS?
Eye diseases can remain dormant for years. Many eye diseases have no symptoms until the harmful process has already caused damage.
Most types of blindness are preventable if diagnosis and treatment are early reached. Regular eye checkups, performed by an ophthalmologist, are very important to highlight any process that may progress quietly, damaging the fragile eye tissues.
Why an ophthalmologist? Because only an ophthalmologist may ensure total care for your eyes, both in prevention and in cases where medical or surgical treatment is required. We recommend a review every one or two years and, in case of a sudden loss of vision or any other condition that causes severe pain or presence of red eye, go immediately to an emergency eye care.