Clinicians treating patients with ocular myasthenia gravis (MG) can suggest some treatment and lifestyle changes that could help to keep them from converting to generalized MG, according to a new study in the American Journal of Ophthalmology. Currently, as many as 80% of patients with ocular MG will convert to the generalized form within two years, adding bulbar, limbal and respiratory muscle issues to the mix.2
However, researchers in Thailand followed 71 patients with seropositive ocular MG and noted several associations that could lower a patient’s risk of conversion. Of the patients with ocular MG, 36 eventually converted to the generalized form in an average of 4.97 years. The team documented the time of onset for both ocular MG and generalized MG, as well as the presence of other autoimmune disorders, history of smoking, any thyroid issues and treatment plans. These demographic and clinical characteristics revealed that female sex, history of smoking and thymic abnormalities were all risk factors for conversion. However, those receiving immunosuppressive agents and pyridostigmine were less likely to experience generalized MG. Clinicians should inform patients of these protective measures, the researchers concluded.1
1. Apinyawasisuk S. Chongpison Y, Thitisaksakul C, Jariyakosol S. Factors affecting generalization of ocular myasthenia gravis in patients with positive acetylcholine receptor antibody. Am J Ophthalmol. September 25, 2019. [Epub ahead of print].
2. Oosterhuis HJ. Observations of the natural history of myasthenia gravis and the effect of thymectomy. Ann N Y Acad Sci. 1981;377:678–90.