Index to this Health
Guide
Clinical
Features
Laboratory Test
Natural History
Treatment
Long Term Management |
Health
Guides on Thyroid Disease
|
|
Graves' eye disease is an eye condition which occurs in about
50% of patients who currently have, or have had, Graves' hyperthyroidism.
However, approximately 10% of patients who have this eye disorder
never develop hyperthyroidism. The reasons for the association
of hyperthyroidism with the eye disease are not completely understood.
Graves' eye disease,
like Graves' hyperthyroidism and Hashimoto's thyroiditis, is an
autoimmune disorder. It is caused by the reaction of antibodies
and certain white blood cells called lymphocytes, with proteins
in eye muscle and the connective tissue and fat around the eyeball.
This condition must be distinguished from the mild eye signs of
"poppy" eyes and spasm of the eye lids which occur in most hyperthyroid
patients due to an effect of excessive thyroid hormones.
|
|
Clinical
Features
The characteristic
features of Graves' eye disease are symptoms of inflammation of
the eye tissues. The eyes are painful, red and watery - particularly
in sunshine or wind. The covering of the eye is inflamed and swollen.
The lids and tissues
around the eyes are swollen with fluid. The eyeballs bulge out
of their sockets. Because of eye muscle movement, the eyes are
unable to move normally and there may be blurred or double vision.
On examination, it
can be seen that the eyes are pushed out of their sockets. This
can be measured using an instrument called an "exophthalomometer."
|
|
Laboratory
Tests
There are no tests
presently available to confirm the diagnosis of Graves' eye disease
although good progress is being made in Canada in the development
of a simple antibody test to measure the proteins in the blood
which cause the eye disease. Such a test would be useful in patients
with Graves' hyperthyroidism to identify those who may be likely
to develop the eye disease.
|
|
Natural
History
The eye changes tend
to "burn out" within a period of about 24 months and, in most cases,
there is a satisfactory end result even without any treatment. The
double vision and the bulginess usually do not disappear completely.
Many patients are worried by the cosmetic appearance of their swollen,
bulgy eyes, whereas others, with less severe defects, are inconvenienced
by their inability to read clearly because of double vision. The
impact of the eye disease also depends on the age, sex, and occupation
of the patient.
Top
|
Treatment
Unfortunately, there
is no satisfactory treatment. Because hyperthyroidism seems to influence
the eye disease, it is very important to treat the hyperthyroidism
quickly and effectively but to avoid hypothyroidism, which also
harms the eyes. In most patients, the eyes tend to get somewhat
better when the thyroid abnormality has been treated.
In a few patients, the condition
progresses regardless of what is done to the thyroid gland. These
patients must be treated with strong drugs such as steroids or immunosuppressive
drugs to prevent the unlikely occurrence of optic nerve swelling
and blindness. If these measures do not work within a few days,
it may be necessary to relieve pressure in the orbit by removing
part of the tissue either by operation or by treating the eyes with
X-rays. Both treatments very quickly reduce the pressure on the
eyeball and the surrounding orbital tissues and prevent permanent
optic nerve damage or glaucoma.
|
Long
Term Management
Once treated, or when
the eyes have "burnt out" without treatment, the eye inflammation
rarely reoccurs and treatment need not be continued. Patients who
have not had thyroid disease previously must be examined on a regular
basis in case they develop thyroid disease. Patients with eye disease
who have had their hyperthyroidism treated previously should also
be examined at regular intervals to make certain that thyroid function
remains normal since recurrence of hyperthyroidism, or development
of hypothyroidism, may cause the eye disease to flare up.
Top
|
A
printed version of this Health Guide is available to health care
professionals and the public. For more information call the National
Office or contact your local
chapter.
Production of
the printed version of this Health Guide was made possible through
partial funding assistance from Health Canada. The views expressed
herein are solely those of the authors and do not necessarily represent
the official policy of Health Canada. |
