Comitant Ocular Deviation in Myasthenia Gravis

Occurrence of comitant ocular deviation in myasthenia gravis (MG) is not well described.A retrospective analysis of patients with ocular or generalized MG evaluated at a neuro-ophthalmology clinic for a 6-year period. Comitant ocular deviation was defined as magnitude of deviations in all planes varying by <20% from the measurement in the primary position.Among the 120 patients included, 89 patients had ocular and 31 patients generalized MG. At the initial strabismus testing, comitant ocular deviation was present in 27 (22.5%) patients. Among the 16 patients who had a follow-up, ocular deviation remained comitant in 6 patients and converted to incomitant or no ocular deviation in 10 patients. An additional 7 patients demonstrated comitant ocular deviation at follow-up. Brain MRI was performed in 18 patients with comitant ocular deviation, and none showed abnormalities in the brainstem or cerebellum.Comitant ocular deviation can be an ocular manifestation of MG. Its presence does not necessarily indicate a central etiology in patients with MG neither excluding a MG diagnosis.