TSH receptor protein is selectively expressed in normal human extraocular muscle.

Thyroid-associated ophthalmopathy is a common manifestation of Graves' disease. Its pathophysiology is not well understood but an antigen shared between the thyroid and orbit is thought to play a role. Using immunohistochemistry, we have demonstrated the presence of the autoantigenic target of Graves' disease, the thyroid-stimulating hormone receptor, in normal human extraocular muscle.