source: University of Michigan, Kellogg Eye Center
Graves’ eye disease, also known as thyroid eye disease, is an autoimmune condition in which immune cells attack the thyroid gland which responds by secreting an excess amount of thyroid hormone. As a result, the thyroid gland enlarges and excess hormones increase metabolism. The hypermetabolic state is characterized by fast pulse/heartbeat, palpitations, profuse sweating, high blood pressure, irritability, fatigue, weight loss, heat intolerance, and loss of hair and alterations in hair quality. When the immune system attacks the tissues around the eyes, it causes the eye muscles or fat to expand.
The eyes are particularly vulnerable to Graves’ eye disease, because the autoimmune attack often targets the eye muscles and connective tissue within the eye socket. This likely occurs because these tissues contain proteins that appear similar to the immune system as those of the thyroid gland. Ocular symptoms can range from mild to severe; but only 10-20% of patients have sight threatening disease. Another tissue that can also be involved in the immune attack of Graves’ eye disease is the skin of the shins.