[Clinical analysis of thyroid associated ophthalmopathy with myasthenia Graves in 12 patients]

To summarized the clinical features of thyroid associated ophthalmopathy patients with myasthenia gravis.

This is a retrospective case series study. The clinical data of 12 thyroid associated ophthalmopathy patients with myasthenia gravis were collected in the 416 Hospital of Nuclear Industry from Oct. 2012 to Feb. 2014. All patients had a detailed medical history including symptoms of onset, the best corrected visual acuity, anterior and posterior segment examination, the exophthalmos, eyelid position, eye movement, diplopia, strabismus, systemic symptoms, concurrent fatigue test, neostigmine test, thyroid function and orbital CT scan. One patient underwent CT examination of thymus.

In all 12 patients, there were 8 females and 4 males with age from 13.0 to 44.0 years (the median age of 26.5 years), 11 cases had difficulties to open their eyes which was least severe in the morning and worsened in the evening. All of cases did not have general symptoms. Ptosis was observed in 9 cases, 3 cases were bilateral, and 6 cases were unilateral. Abnormal extra ocular muscle function was observed in 8 cases, all of them were bilateral. In these 16 eyes, the limitation of downward gaze were observed in 15 eyes, the limitation of upward, outward and inward gaze were observed in 14 eyes, eye fixation occurred in 4 eyes. Four cases had diplopia, 3 cases had strabismus, and 2 of them were exotropia. Orbital CT demonstrated extraocular muscle thickening in 6 cases. Thickening of inferior rectus were observed in all 12 eyes, superior rectus and medial rectus were found thickened in 6 eyes, and thickening of lateral rectus muscle was found in 3 eyes.

The clinical features of thyroid associated ophthalmopathy patients with myasthenia gravis were complex. When ptosis and eye movement disorders were not consistent with TAO severity, associating with exotropia and systemic muscle paralysis, myasthenia gravis should be considered.