Graves
disease is an autoimmune disease. This means that the immune
system, the white blood cells, are attacking your own body. You may have heard of other diseases where the immune system attacks
the patient's own body. In Rheumatoid Arthritis, the white
blood cells attack the joints. In Lupus, they attack the lungs. In the commonest type of Graves disease, the white blood cells attack
the thyroid gland, releasing thyroid hormone. Testing the
blood for the level of thyroid hormone confirms the diagnosis. This hormone affects many systems of the body.
In a small
percentage of patients with Graves disease, the white blood cells
also attack the fat and muscles behind the eyes, causing
 inflammation
of and around the eye
swelling
of the upper and lower eyelids
pain
around the eyes
sometimes
double vision
rarely,
loss of vision.
The inflammation
usually lasts from six months to two years. The attack on
the tissues behind the eye can happen before the thyroid is attacked,
at the same time, or later. In most patients with Graves disease
the immune system, white blood cells, attack only the thyroid and
not the eyes. Graves eye disease is much more common in people
who smoke. In some patients the attack can be on the tissues behind
the eye and not on the thyroid gland, so that the thyroid blood
tests are negative. In that case, the diagnosis is made by
seeing enlarged muscles behind the eyes on the CAT scan (a kind
of x-ray), and sometimes by a special blood test for chemicals (antibodies)
attacking the thyroid.
When
Graves disease affects the eyes, several problems can occur:
The
inflammation can result in redness of the eye and pain and pressure
around the eyes. If it is mild, this can be treated with medications
like Advil. In more severe cases, prednisone pills are used.
The
eyelids can open too widely, and this interferes with the way the
eyelids blink and lubricate the eyes, resulting in irritation of
the surface of the eyes and discomfort. This is treated initially
by using lubricating eye drops. After the disease has stabilized,
the eyelids can be placed back into their normal position by surgery.
When
the muscles are swollen they cannot move the eyes smoothly, and
if the two eyes do not move together, then double vision can result.
This can be treated by special glasses or surgery.
If
the swelling behind the eyes is severe, the eyes can be pushed forward
in the socket (orbit). The pressure behind the eyes can damage
the optic nerve, which carries the image from the eye to the brain,
decreasing the vision. The first treatment is with prednisone
pills. Some patients require surgery, which opens the bones around
the orbit to allow more room for the swollen muscles, relieves the
pressure on the optic nerve, and allows the eye to move back into
the orbit.
The eye
symptoms of Graves disease can be quite distressing and can last
for some time. Once the disease has stopped evolving, corrective
surgery can generally improve the comfort, eliminate the double
vision, and even improve the appearance of the eyes. |
