Journal List > J Korean Ophthalmol Soc > v.53(7) > 1009126

Moon and Kim: Ocular Myasthenia Gravis in Conjunction with Thyroid-Associated Ophthalmopathy: A Case Report



To report a case of ocular myasthenia gravis in conjunction with thyroid-associated ophthalmopathy in a patient who showed incomitant strabismus and blepharoptosis as well as to discuss the clinical features and tests that may help distinguish these 2 diseases.

Case summary

A 46-year-old man without any previous history of systemic and ophthalmic disease presented with binocular diplopia that occured a month earlier. The patient had no other systemic symptoms except a 7 kg weight loss within the last month. The patient was referred to the department of internal medicine and brain magnetic resonance imaging was performed to ascertain the cause of suspected left superior oblique muscle palsy. The patient was diagnosed with Graves' disease and underwent medical treatment. One month later, the patient presented with consistent diplopia and exophthalmos and showed a swelling of eyelid and ptosis in the right eye. Intravenous high-dose steroid therapy was administered to the patient. After the treatment, symptoms of diplopia and lid swelling were improved, however ptosis persisted. Ocular myasthenia gravis was suspected and various tests were conducted. Anti-acetylcholine receptor antibodies were detected in large amounts and ptosis was improved dramatically by an administration of an anticholinesterase agent. The patient was diagnosed with ocular myasthenia gravis in conjunction with thyroid-associated ophthalmopathy.


Ocular myasthenia gravis should be suspected in patients with thyroid-associated ophthalmopathy who have signs or symptoms of ptosis.

Figures and Tables

Figure 1
The patient showed a ptosis in the right eye (A). A ptosis was improved after treatment with Pyridostigmine (B).
Figure 2
Orbital computed tomography showed a thickening of the right medial rectus muscle.
Figure 3
Repetitive nerve stimulation test, which performed in the left abductor digiti minimi shows a normal response.
Table 1
Comparison of thyroid-associated ophthalmopathy and ocular myasthenia gravis

CT = computed tomography; EOM = extraocular muscles; Anti-AchR-Abs = anti-acetylcholine receptor antibodies; MG = myasthenia gravis; OMG = ocular myasthenia gravis; RNST = repetitive nerve stimulation test.


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