Graves’ disease is an autoimmune condition and is a common cause of hyperthyroidism. One of the effects involves bulging and inflammation of the eyes, known as Graves’ ophthalmopathy. Many patients with Graves’ develop some degree of eye related symptoms, but only about 5% will experience severe ophthalmopathy manifestations.
Causes and symptoms
TSH receptors and cells of immunity in the eye area play a major role in Graves’ ophthalmopathy. Thyroid eye disease causes the muscles and soft tissues within the eye socket to swell.
There is limited space inside the orbit so, as the tissues swell, the eyeball is pushed forward, causing various negative eye symptoms. These can range from mild to severe, where the eye is pushed far enough forward that the eyelids don’t close properly, leaving the cornea dry and unprotected. The muscles that control the eyeball don’t work as well and the eyeball cannot move so easily. When the disease is very severe, the nerve connecting the eyeball to the brain can be compressed and damaged.
The most common symptoms of thyroid eye disease are: pain behind the eye, redness and irritation, dryness of the eyes, double and/or blurred vision, sensitivity to light, difficulty moving the eyes, bulgy look of the eyes.
Diagnosis and Treatments
Doctors can diagnose your thyroid eye disease by simply examining your eyes if you already have a diagnosis of a thyroid gland problem. If the doctors need to look at the amount of swelling in the eye socket and which tissues have been most affected, they may require an MRI scan. They may also assess how well you see colors and whether your peripheral vision is impaired. The assessment may also include an eye movement test to see how the muscles have been affected.
With thyroid eye disease, the eye inflammation may gradually go away by itself. When the eye is inflamed, the aim of treatment is to limit inflammation, swelling and to to protect the surface of the eye. However, the physical changes caused by the swelling (such as bulging eyes) may remain. This is because some of the tissues that have been stretched may not return to their original form. There are also treatments for people whose tissues have not been able to return to their original form after the inflammation has settled.
Traditionally, the treatment of Graves’ ophthalmopathy has depended on the affected area. Treatments include glucocorticoids for inflammation, orbital decompression when there is threat to vision, and muscle surgery for diplopia.
Inflamed lacrimal glands may cause wet or dry eyes, which can both happen in the same patient at different times. Lubrication with eye drops or ointment can help to soothe this irritation. The abnormal immune reaction causes swelling in the tissues of the eyelids and orbit, which can make the eyelids, look puffy. 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.
With severe cases where the optic nerve (connecting the back of the eyeball to the brain) is compressed the vision could be permanently damaged. In such situations you may need decompression surgery, a procedure that creates a space within the eye socket for the inflamed tissues to spread into. This relieves the pressure on the nerve.
If you develop double vision (diplopia), you may be referred to a specialist who manages problems with eye muscles (an orthoptist). They may give you modified glasses that block off vision from one eye (like a patch) or put a special cover, called a prism, over one side to stop the diplopia.
With thyroid eye disease, the inflamed period can last anywhere from a few months to a few years, after which there is a healing response. For most people the condition will be mild, needing lubricants and regular assessments only. For those with a more severe form of the disease, the outlook depends on how early it is diagnosed and how intensive the treatment is.
Since the eyes are so delicate and physiologically important, choosing the right therapeutic tool is essential in order to preserve function and minimize disability. It is also very important to address the root cause of your eye disorder, which is the autoimmune illness itself. Finding a doctor that is knowledgable and will give you the treatment you need is key to improving your health!