Thyroid eye disease presenting after cataract surgery.

Strabismus presenting after cataract surgery has been attributed to a variety of disorders, some of which are unrelated to the surgery. When thorough ophthalmologic and neurologic examinations fail to elucidate a definitive etiology, the motility disturbance is often ascribed to operative trauma to the orbital soft tissues. In a series of 58 patients with strabismus presenting after cataract surgery, eight (14%) were found to have previously unsuspected thyroid eye disease. Three of the eight patients had past histories of systemic dysthyroidism, but none reported diplopia prior to cataract extraction. Three of the remaining five patients showed normal thyroid function tests. Absence of diplopia prior to cataract extraction in these patients may be due to: 1) poor vision precluding diplopia until surgical restoration of sight; 2) intraoperative aggravation of the inflammatory process in otherwise subclinical thyroid eye disease; or 3) onset of clinical thyroid eye disease that was temporally associated with cataract surgery by chance. Thyroid eye disease should be included in the differential diagnosis of all patients presenting with binocular diplopia following cataract surgery. Suitable neuroimaging studies may be needed to confirm the diagnosis.