What are the symptoms? Swelling of the damaged tissues behind the eyes can cause the eyes to become red and swelling to occur above and below the eyes. It may also cause the eyes to be pushed forward (‘starey eyes’, ‘proptosis’). In more severe cases, the damage at the back of the eye causes swelling and stiffness of the muscles that move the eye, causing double vision. This occurs especially when looking from side to side as the muscles cannot keep the eyes exactly in line with each other. Occasionally, the swelling behind the eyes is severe enough to press on the nerve from the eyes to the brain affecting vision. Other features that may occur include mild soreness and grittiness of the eyes usually only affecting one eye, increased watering of the eye, a dislike of bright lights and a feeling of discomfort behind the eyes especially when looking up or side to side. Puffiness of the upper eyelid or around the eyes giving the impression of baggy eyes is also common and is worse first thing in the morning. The eyes often appear ‘starey’ and drying of the eyes or too many tears can cause blurry vision which comes and goes. What are the causes? Ninety per cent of people with thyroid eye disease also have an overactive thyroid gland (thyrotoxicosis). Graves’ disease is a type of thyrotoxicosis which is autoimmune in aetiology. A feature of both Graves’ disease and thyroid eye disease is thought to be the common molecule, the thyrotrophin stimulating hormone (TSH) receptor to which stimulating antibodies develop. Thyroid eye disease and an overactive thyroid gland do not always develop at the same time and the treatment for one does not affect the treatment of the other, with the exception of radioactive iodine treatment. A small number of people with thyroid eye disease may have an underactive thyroid with some having no thyroid disturbance at all. How is it treated? Treatment for thyroid eye disease depends on the severity and ranges from simple eye drops to immunosuppressive therapy and decompressive surgery. The most important aspect of treatment is the preservation of eyesight. Inheritance patterns and prenatal diagnosis Inheritance patternsNone. Prenatal diagnosis None. Is there support? Thyroid Eye Disease Charitable Trust Tel: 0844 800 8133Email: firstname.lastname@example.orgWebsite: tedct.co.uk The Trust is a Registered Charity in England and Wales No. 1095967. It provides information and support to all those affected by thyroid eye disease. Group details last updated September 2014.