Eye involvement in Graves’ Disease
Amongst all the medical specialties, ophthalmology leads the field in terms of technical and technological innovation. This doesn’t just apply to lasers on the cornea and robots in the retina: it applies to orbital surgery too.
Graves’ Disease is an autoimmune disease that affects the thyroid, and is the most common cause of hypothyroidism (an underactive thyroid). Most people with Graves’ Disease go on to have eye problems, particularly exophthalmos (eye bulging). What causes this is endocrine orbitopathy: the eye muscles thicken so much that there’s no longer enough space in the eye socket to accommodate the eye. The eyeball starts to be pushed forward and starts to bulge outwards – which can have increasingly dire consequences for the eye if left untreated. But it causes another problem: patients can become disturbed and distressed by this change in their self-image.
Endocrine orbitopathy (EO) usually occurs in both eyes at the same time, but its time of onset does not necessarily coincide with the start of thyroid disease. Sometimes endocrine orbitopathy occurs at the same time, sometimes it is the first sign of Graves’ disease, and sometimes it occurs only after some time after other thyroid dysfunction symptoms manifest. In about 10% of cases, endocrine orbitopathy even occurs without any sign of thyroid disorders.
The symptoms of EO can be extremely different. People with EO regularly report symptoms of dry eye (tears, burning, photosensitivity, blurred vision, foreign body sensation, pressure behind the eye). In addition, other signs of inflammation may occur (swollen eyelids, swollen conjunctiva, redness of the eyes). But one of the most common signs is exophthalmos, which usually presents with upper eyelid retraction and a low blink rate. As the disease progresses, diplopia (seeing double) can start to occur.
The endocrine orbitopathy often extends over months to years and typically follows a course of increasingly progressive symptoms (known as the “active phase”) which is eventually followed by a phase of remission (burnt out/inactive phase).
Effective medical therapy to treat EO is essentially limited to oral steroid use – but the side effects of steroid use – particularly when used for extended periods – are often unpleasant. Unfortunately, if a person with EO stops taking steroid therapy, the disease recommences. The alternative to this is ocular surgery to improve the ocular eye’s position in the eye socket. This is called orbital decompression surgery. This can only be done when the endocrine orbitopathy has come to rest. We will do such an operation only after consultation with the treating endocrinological team.