Thyroid eye disease
What is thyroid eye disease?
Thyroid eye disease is an auto-immune disease of the orbit (eye socket) and eye muscles that occurs in people with thyroid disease. It is characterised by inflammation, swelling and eventual scarring.
Who gets thyroid eye disease?
Thyroid eye disease is most commonly seen in people with Graves' disease (hyperthyroidism) but it can also occur with hypothyroidism, Hashimoto's thyroiditis, and thyroid cancer. About 40 per cent of people with Graves' disease will develop thyroid eye disease. Most cases of thyroid eye disease develop shortly before, or soon after the diagnosis of hyperthyroidism is made. Some people do develop thyroid eye disease a long time before or a long time after their thyroid problem becomes apparent.
What are the features of thyroid eye disease?
Thyroid eye disease has 2 distinct phases:
- The first phase is characterised by active inflammation and swelling. In this phase the eye is often red and inflamed. The lids are swollen and the eye is "poppy". Often in this phase there is quite a bit of discomfort and ache, especially at night.
- As this phase resolves the muscles that move the eye begin to scar and malfunction. In this phase the upper eyelid often ‘retracts’ (sits up too high) and double vision is common. Commonly in this phase the appearance of the eye remains prominent.
Either phase can be accompanied by irritation, a feeling that there is something in the eye and visual blurring.
What can be done to help?
There is much that can be done to help patients with thyroid eye disease. The ocular irritation is helped by simple lubricants (Tears Plus or Liquifilm Tears). The swelling and ache may be helped by sleeping with the head of the bed elevated by one or 2 bricks and by using cold compresses (available from the chemist).
During the acute inflammatory phase some patients benefit from oral steroids (prednisolone) to reduce the swelling and help the pain (and visual loss). Oral steroids must be used with caution as they have many side effects including worsening the mood disturbances that thyroid patients often develop. Some patients in this phase will require radiotherapy for the swelling.
During the scarring phase of thyroid eye disease many people require surgery for their thyroid eye disease. Surgery can be used to lower the upper eyelid if it is abnormally raised. Surgery can be used to reduce the ‘poppyness’ (proptosis) of the eyes. If double vision is a problem then this can be fixed by surgery to move the eye muscles. All of this surgery is best delayed until the eye disease is as stable as possible. With any surgery it is important to weigh the potential benefits against the potential risks.
Obviously patients with hyperthyroidism will require treatment for their increased thyroid hormone levels but disappointingly this correction of their hyperthyroidism often doesn't help their eye disease a whole lot.
What happens in the end?
Unfortunately for many people who develop it, thyroid eye disease is a long term problem. The acute inflammation and swelling nearly always resolve within a few months but many patients are left with permanent abnormalities. About one-third of people with thyroid eye disease will have ongoing dryness, sensitivity and irritation. About half of patients believe that their eyes continue to look abnormal. The good news is that with current treatments long-term double vision and visual loss are very uncommon.
If you have any questions you should speak to your endocrinologist or ophthalmologist.
Dr Anthony Hall
Dr Anthony JH Hall MD, FRACO is Director, Ophthalmology Unit, Royal Melbourne Hospital