Graves’ eye disease
One feature of Graves’ disease that is different from other types of hyperthyroidism, is its effects on the eyes. Graves’ disease is the only type of hyperthyroidism that is associated with swelling and inflammation of the eye tissue.
Graves’ eye disease, also known as ophthalmopathy (exophthalmos), affects around half of people with Graves’ disease. The eyes can become:
Due to the increased pressure on the optic nerves, untreated Graves ophthalmology can lead to double vision and possibly partial blindness.
It is still unclear why Graves’ disease affects the eyes in this way. The severity of the condition does not correlate with the severity of eye symptoms; it can occur before the condition begins, or even without Graves’ disease.
Smoking is a risk factor for Graves’ disease.
Graves disease affects the thyroid gland, a butterfly-shaped organ at the base of the neck, just below the Adam’s apple. It is an important part of the endocrine, or hormonal, system. It regulates metabolism by releasing hormones into the bloodstream.
Hormones released by the thyroid gland help keep the body’s metabolism running at the right rate. The more hormones it releases, the more quickly metabolism runs. Normally, a chemical called thyroid-stimulating hormone (TSH) produced in a part of the brain called the pituitary, tells the thyroid how much or how little to produce.
In Graves’ disease, the immune system produces antibodies that trigger the TSH receptor, tricking the thyroid into making too many hormones, which speeds up metabolism, causing the symptoms below.
Scientists do not know the exact cause of Graves’ disease. We know that, somehow, the body’s immune system is tricked into targeting receptors on the thyroid gland, causing hyperthyroidism.
Research suggests that Graves’ disease may be caused by a combination of genetic and environmental factors.
- Genetic – A family history of Graves’ disease increases the chance of developing the condition, although its inheritance pattern is unknown.
- Environmental – you are much more likely to develop Graves’ disease if you smoke.
Other people who have an increased risk include:
- Individuals with other autoimmune diseases.
- Women who have recently given birth or are pregnant.
- Individuals under emotional or physical stress.
Graves’ disease can be difficult to diagnosis at first. Aside from ophthalmopathy, most of the symptoms of Graves’ disease are shared with other conditions.
Thyroid-stimulating hormone (TSH) stimulates the thyroid gland to release thyroxine (T4) and triiodothyronine (T3); a doctor may take a blood sample to measure levels of these hormones.
Abnormally high levels of T3 and T4, and a very low level of TSH, are good indications of Graves’ disease.
Another test for Graves’ disease is called radioactive iodine uptake. The patient consumes a small quantity of radioactive iodine by liquid or capsule. Once swallowed, the iodine collects in the thyroid.
The doctor will then perform several scans using a radioactive tracer. The first is usually done 4-6 hours after the iodine has been taken. Following this, a second scan is usually taken 24 hours later.
Graves’ disease can cause a sensitivity to iodine, according to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Iodine is found in seaweeds, such as kelp and dulse.
Consuming foods that are rich in iodine or taking iodine supplements may make the symptoms of Graves’ disease worse.
Any dietary changes should be discussed first with a physician.
The NIDDK also advises people to speak to their doctor before taking a multivitamin supplement or using cough medicine, as these can contain iodine.
The National Library of Medicine notes that, with the correct treatment, Graves’ disease usually responds well to treatment.
It is important to attend all scheduled health appointments, however, because treatment for an overactive thyroid can trigger an underactive thyroid, or hypothyroidism.
Symptoms include a lack of mental and physical energy, weight gain, and depression.