Thyroid eye disease is an autoimmune disorder and is also known as thyroid associated ophthalmopathy, Grave’s ophtalmopathy or orbitopathy. It is the most common condition that affects the soft tissue and muscles around the eye orbits and generally occurs together with hyperthyroidism (overactive thyroid gland).
Risk Factors For Thyroid Eye Disease
Thyroid disease. Between 25 and 50% of patients with Grave’s disease in addition to hyperthyroidism also have thyroid eye disease. About 3% of people with Hashimoto’s disease and 10% of patients without Grave’s disease but with high level of thyroid antibodies could also develop this condition.
Hyperthyroidism seems to influence the clinical course of thyroid eye disease. Early diagnosis and control of hyperthyroidism may be associated with a better outcome of the treatment.
Age. Although ophthalmopathy may occur at any age the risk of developing the condition appears to increase with the age of the patient. There are two peaks of incidence of the disease within women in the age groups of 40 to 44 and 60 to 64 years old, and some 5 years later in men.
Sex. The incidence of thyroid eye disease in women is 5 times higher than in men. It is important to treat the overactive thyroid, however the onset of the thyroid eye disease could be delayed or initiated before hyperthyroidism. It happens because the regulation of thyroid hormone levels does not prevent the underlying autoimmune process from affecting the tissues around the eyes.
Thyroid Eye Disease Symptoms
In most affected individuals, changes are noticeable in both eyes, however each to a different degree. The majority of patients show mild symptoms such as:
- pre-orbital swelling
- conjunctivitis which is an inflammation of the outermost layer of the eye (cornea) and the inner surface of the eyelids
- pressure and irritation around the eyes
- incapacity to close the eyelids completely
- dryness and redness of the upper eyelids
- edema which is a swelling around the eyes
- tearing of the eyes.
Approximately one third of cases are severe enough where the thyroid eye disease patients have one or more of the following symptoms:
- intensive pain
- reduced mobility of the eyes due to inflammation
- double vision
- keratopathy which is a non-inflammatory disease of the cornea with possible impaired visual function
- proptosis which is the bulging of the eyes
- acute inflammation of the soft tissue
- damage and compression of the optic nerve that leads to progressive loss of vision.
Causes Of Thyroid Eye Disease
While the exact cause of thyroid eye disease is unclear there are some factors contributing to this condition:
Autoimmunity. There are six muscles controlling the movements of the human eye and eyelids. Thyroid antibodies attack the cells of connective tissue in these eye muscles called fibroblasts causing the orbital fat deposits to increase. Fat cells and muscles significantly enlarge and become inflamed. Additional compression of the veins makes them unable to drain the fluids causing swelling. Depending on the amount of tissue grown behind the eye, it could be pushed outward causing bulging of the eye.
The role of Genetic factors are purely understood. Thyroid diseases run in the families. However, it appears that environmental factors play a more important role than do genetic factors in the development of the disease.
Cigarette smoking is an environmental risk factor for the development and severity of thyroid eye disease. In addition, cigarette smoking has been noted to decrease the effectiveness of orbital radiotherapy and high-dose glucocorticoids treatment.
How Is Diagnosis Of Thyroid Eye Disease Made
There are two phases in development of the thyroid eye disease: active and inactive. Active phase normally lasts from 6 months to 2 years and involves changes in eye orbits, surrounding tissues and vision.
A diagnosis of Graves’ ophthalmopathy is based on the following tests:
- family history of autoimmune thyroid diseases
- presence of ocular signs and symptoms
- positive tests for antibodies (anti-thyroglobulin, anti-microsomal and anti-thyrotropin receptor)
- abnormalities in thyroid hormones level (suppressed TSH, high T3 and T4)
- MRI
- According to thermography, the temperature in the eye orbits is significantly increased among the patients with eye thyroid disease indicating the active inflammatory process. A positive correlation was noted between the severity of disease and temperature.
Learn About Treatment For Thyroid Eye Disease
Correction of hyperthyroidism is important to minimize the risk of thyroid eye disease. Continued high thyroid activity and associated autoimmune reactions contribute to the progression of the ophthalmopathy.
There is a strong evidence that smoking could worsen the course of the thyroid eye disease and decrease its response to treatment. All patients with Graves’ disease are advised to stop smoking irrespective of the presence or absence of ophthalmopathy.
During the active phase the following treatments could be used to reduce the swelling and inflammation:
- Corticosteroids. Up to 77% of patients see improvements in their condition after using oral or intravenous corticosteroids that work as an immunosuppressive and anti-inflammatory agents. These drugs are very effective in reducing swelling around the eyes and protecting the vision from deterioration. However, the use of corticosteroids is often limited from 3 to 5 months due to side effects such as weight gain, blood sugar irregularities and medication induced diabetes. The recurrence of the disease is common after getting off the treatment.
- Orbital radiation is applied to the tissues behind the eyeball and could improve movement ability of the eye. Normally the patient gets 10 doses of radiation therapy over the period of two weeks, however only two thirds of patients benefit from the treatment. Radiation and corticosteroid combination therapy is more effective than either of them used alone.
After the active phase is over and the condition is stabilized the following rehabilitation surgeries could be an option:
- Surgical therapy could relieve the acute compression of the optic nerve and decrease chronic orbital inflammation. Eye muscle surgery could improve double vision and misalignment of the eyes. Eyelid surgery could restore eyelid function, improve eyelid closure and appearance.
- Orbital decompression includes the removal of some of the surrounding bone and soft tissue to provide more space for the swollen eye muscles located in the orbit.
Depending on the severity of thyroid eye disease and effectiveness of treatment it could take up to 1 or 2 years to see improvement in the mild cases. If the disease is severe or profoundly advanced the chances for improvements are low and visual damage permanent. Visual changes in people with eye thyroid disease could have a large impact on their psychological state and quality of life.
There are alternative methods to reduce inflammation, eye pain and improve bulging eyes using natural preparations.
P.S.
If you got here from Twitter or was referred by a friend you could subscribe for the Thyroid in Women blog updates here
References:
The eye and thyroid disease. Curr Opin Ophthalmol. 2008 Nov;19(6):499-506.
Graves’ ophthalmopathy: a preventable disease? European Journal of Endocrinology. 2002 146 457–461
