Ocular myasthenia gravis associated with euthyroid ophthalmopathy

We report a 71-year-old woman with concomitant ocular myasthenia gravis and euthyroid Graves' ophthalmopathy. Unilateral ophthalmoplegia, including ptosis, initially was responsive to edrophonium and corticosteroids, except for diplopia on upward gaze, but refractory swelling of the inferior rectus muscle and proptosis followed. Autoantibodies to acetylcholine and thyrotropin receptors were detected. Her ophthalmopathy abated after orbital irradiation in combination with systemic steroids. There may be an immunological basis for the association of ocular myasthenia gravis with euthyroid Graves' ophthalmopathy.