Ocular myasthenia gravis (OMG) is an autoimmune disorder associated with neuromuscular junction abnormalities at the ocular muscle level. Around 50% to 60% of patients with myasthenia gravis (MG) initially present with ocular symptoms such as ptosis, ophthalmoplegia, and diplopia. Moreover, 50% to 60% of patients presenting with OMG subsequently progress to generalized MG (GMG), commonly within 1 to 2 years.
However, the diagnosis of OMG based on clinical findings is often challenging because OMG should be considered in the differential diagnosis of any pattern of painless, unilateral or bilateral, pupil-sparing ophthalmoplegia with or without ptosis. In most patients, MG can be caused by auto-antibodies against the nicotinic acetylcholine receptor. It was observed that both ptosis and diplopia were significantly higher. After excluding of cranial nerve palsy, if there is ptosis and diplopia, especially vertical diplopia, the possibility of OMG should be considered.
