Optical neuropathy is a serious complication, occurring in 5% of patients with endocrine ophthalmopathy. It develops due to compression of the optic nerve or vessels feeding it at the apex of the orbit with edematous and enlarged rectus muscles.
Upper and lower eyelid retraction occurs in approximately 50% of patients with Graves disease. At the heart of the retraction are the following mechanisms.
Exophthalmos is an excessive shift of the eye anteriorly, caused by a retrobulbar injury or (more rarely) a shallow orbit. Asymmetry of the eye is better seen when examining the patient from above and from behind.