Thyroid Eye Disease
(Graves' Eye Disease)
Graves’ eye disease, also known as thyroid eye disease, is an autoimmune condition in which immune cells attack the thyroid gland which responds by secreting an excess amount of thyroid hormone. In thyroid eye disease, the immune system sets off an abnormal reaction to the muscles and fatty tissue around the eyes. The symptoms that occur in thyroid eye disease include dry eyes, watery eyes, red eyes, bulging eyes, a “stare,” double vision, difficulty closing the eyes, and problems with vision. Although many patients with thyroid eye disease will have abnormal blood tests for thyroid hormone levels, there are some people who get the eye symptoms even with normal hormone levels.
Eye Symptoms and Treatment
Thyroid eye disease can affect many different parts of the eye and surrounding tissues. Inflamed lacrimal glands may cause wet eyes or dry eyes. The abnormal immune reaction causes swelling in the tissues of the eyelids and orbit which can make the eyelids look puffy or as if the person has “baggy” eyelids. This can also create a sensation of pressure around the eyes. The swelling can be surgically altered to bring the lids back to a more normal shape.
The muscles in the eyelids tighten and pull the upper lid up and the lower lid down. This creates a startled look with too much of the whites of the eyes showing. This also can be surgically improved. The muscles which control movement of the eyes may be increased in size by the swelling. This can create problems with double vision and focusing. Prism glasses may be helpful, and this can also be improved by surgically moving the eye muscles.
There may be difficulty in closing the eyelids because the eye may be pushed forward and the eyelids pulled open by the muscles. This can lead to a corneal ulcer. A second danger to vision occurs when swollen tissues compress the optic nerve. The optic nerve functions as an extension cord between the eye and the brain to carry the message of vision. When the nerve is compressed, color vision is abnormal, lights may seem dimmer than usual, and the sharpness of the vision decreases. These changes may be reversed with treatment, but could progress to permanent loss of vision.
The treatment options for vision-threatening problems in thyroid eye disease include corticosteroids or other anti-inflammatory medications, radiation and surgery. A combination of these may be necessary to protect vision. Most people with thyroid eye disease do not get corneal ulcers or optic neuropathy, but it is important to understand the symptoms so you know when to seek help.