Myasthenia gravis (MG) presents challenges in diagnosis due to its ability to mimic various neurologic and ocular motility disorders, including pseudo-internuclear ophthalmoplegia. Two cases of ocular MG highlight the diverse ocular motor deficits it can manifest, ranging from exotropia to pseudo-internuclear ophthalmoplegia, without necessarily presenting with ptosis. The absence of ptosis, though less common, particularly in younger patients, does not exclude ocular MG, which may initially present with reduced visual acuity attributed to accommodative excess rather than accommodation insufficiency.

These cases underscore the importance of considering ocular MG in patients presenting with ocular motor deficits and reduced visual acuity, even in the absence of ptosis. While the diagnosis may be challenging, especially when ocular motor deficits mimic central disorders, awareness of the varied presentations and the potential for accommodative excess leading to reduced visual acuity is crucial for accurate diagnosis and appropriate management.

Reference: Young A, Johnston JL. Pearls & Oy-sters: Ocular Myasthenia Gravis: Central Ocular Motor Signs and Unilateral Visual Loss Caused by the Great Neuro-Ophthalmologic Impersonator. Neurology. 2024 Mar 26;102(6):e209260. doi: 10.1212/WNL.0000000000209260. Epub 2024 Feb 20. PMID: 38377456.