Grave’s Disease: Symptoms That Affect The Eyes

Graves’ Disease is classified as an autoimmune system disorder and is one of two conditions where excess production of thyroid hormone results in a state of hyperthyroidism. 

Graves’ orbitopathy (GO) or Graves’ ophthalmopathy are the terms given to thyroid eye disease (TED) and the subsequent eye changes which result from Graves’ disease. That being said, TED can also happen to people who don’t have Graves’ disease. 

How Grave’s orbitopathy (GO) develops

In Graves’ Orbitopathy (GO), the tissues in and around the eyes become swollen and inflamed. This occurs as a result of an autoimmune attack on these tissues surrounding the eyes (the same autoimmune attack that occurs in the thyroid gland in Graves’ Disease).

This attack causes both an increase in fat cells (adipocytes) and muscle cells (myofibroblasts) in the eye and a sudden inflammation of the eye socket. The inflammation and swelling can stop the eye muscles from working properly.

If the eye muscles cannot function properly, the eyes may be unable to completely close, resulting in blisters and infections. Likewise, visual changes may occur from the eyes being unable to move in a coordinated way.

The inflammation can also cause an increase in pressure in and behind the eyes (in the eye socket), which can affect the optic nerve (a nerve going from your eye to your brain) and cause visual disturbances, or in extreme cases, blindness. 

Symptoms of Graves’ disease in the eyes

Graves’ disease can cause quite a few unpleasant symptoms in the eyes. You may notice swelling around the eyes, redness, bulging eyes, pulled-back eyelids, double vision, and blisters.

On examination of someone with Graves’ disease of the eyes, a medical professional may detect corneal disease, increased eye pressure,  restrictive strabismus (malalignment of the eyes from muscle swelling), and sometimes optic nerve compression. 

If these symptoms go untreated, they can cause permanent damage.

Swelling around the eyes (periorbital edema)

This is thought to occur mainly from the buildup of fluid from the veins not being able to drain properly because they are too compressed in the eye socket (orbital space).

The swelling observed is also a result of certain cells collecting and causing changes in and around the eyes. These changes include an increase in fatty tissue and swelling of the muscles themselves.

The end result of all this swelling is an increase in pressure in the eye socket, which can compress the optic (eye) nerve, causing visual problems. 

Bulging eyes (proptosis)

The increased pressure from the soft-tissue swelling and enlargement in the eye socket can cause bulging eyes as the eyeball protrudes outwards.

Eye malalignment (restrictive strabismus)

Controlled eye movements are achieved when the eye muscles move together in a coordinated way. The swelling of eye muscles in GO stops them from working well together, compromising their function and resulting in restricted eye movements. 

The restricted movement of the eyes results in muscles that control eye movements being misaligned and uncoordinated, which can cause a condition called ‘restrictive strabismus.’ Restrictive strabismus can be caused by inflammation, scar tissue, and subsequent swelling of the muscles outside the eye (called the extraocular muscles), which can cause double vision as the eyes do not work together properly.

Double-vision (diplopia)

When the eye muscles become inflamed and swollen, an increase in pressure on a nerve that goes to the eye - the optic nerve - can happen. This can cause double-vision or loss of vision in extreme cases. 

Corneal disease (exposure keratopathy)

Normally, the eyelids protect the cornea in the eye from trauma, blisters, drying out, and infection. When the eyelids can’t close completely, as in the case of GO, the cornea becomes too exposed and is no longer protected. 

The symptoms of this will be burning, increased production of tears, intermittent blurry vision, and cosmetic changes as a result of infection to the eye. 

Prevalence and risk factors of GO

GO typically affects about 25-50% of people¹ with Graves’ disease, although it can be detected in about 20% of patients before the onset of hyperthyroidism. It often involves both eyes; however, in 15% of patients, it can either occur in only one eye or affect one eye more than the other.

The occurrence of GO in Graves’ disease patients is normally between the ages of 40-44 years and between 60-64 years in women, and between 45-49 years and between 65-69 years in men. However, in children, the development of GO is rare.

There are some significant differences in the effects of GO on patients of different races. This is largely due to the differences in the anatomy of the eyes. 

For example, the Asian population has shallower eye sockets which can lead to a greater chance of compression of structures in the orbital space (because there is less room). Having said this, Caucasians have been found to have a much higher chance of developing GO, with more extensive symptoms than other races.

If you have radioactive iodine treatment for Graves’ disease, you are 15-20% more likely for GO to develop or progress. 

Finally, cigarette smoking has been shown to be a lifestyle factor linked to the development and progression of GO. A comprehensive review² showed that cigarette smoking will affect the development and severity of the disease and the success of treatment.

The lowdown

Graves’ disease can cause harmful eye-related symptoms in 25-50% of patients. These can include symptoms such as dry eyes, irritation, redness, swelling, uncoordinated movements, and visual changes. It can be made worse by lifestyle factors such as smoking, and unfortunately can often get worse with age. 

There are treatments available, so it is important to seek help if you have Graves’ disease and are experiencing eye-related symptoms.