This study collects the clinical data of new-onset ocular myasthenia gravis (OMG) patients, assesses outcomes and adverse effects of different treatment options, and evaluate risk factors of conversion to generalized MG(GMG).

This is a multicenter, observational cohort trial in the real-world clinical setting recruiting new-onset OMG patients from Neurology Departments of 7 hospitals in different regions of China. Clinical manifestations, laboratory test results, chest imaging and history of thymectomy are recorded. Treatment option are determined according to the physician's judgment and preferences of the patients. Patients are followed up prospectively on regular to assess the outcomes of treatments and monitor any side effects. Peripheral blood samples are collected annually. The investigators plan to recruit a final sample of 200 patients for analysis.

Inclusion Criteria:

1. Age >18 years and<75 years;

2. Clinical Diagnosis of MG with supporting evidence:

   Patients with ocular muscle type MG who have never received treatment meet one of the diagnoses (1) and (2)-(5): (1) The patient's symptoms involve the extraocular muscles, except for drooping eyelids and diplopia, no other clinical symptoms; (2) unequivocal clinical response to pyridostigmine; (3) positive acetylcholine receptor antibody or musk antibody; (4) decrement of more than 10% in repetitive nerve stimulations study (RNS); (5) the "trembling" of the single fiber electromyography (SFEMG) is broadened with or without blockade;

3. Willingness to sample collection, imaging study and other disease-related examinations and assessments;

4. The results of pregnancy tests for female subjects with fertility during the screening period should be negative and effective contraception was used by the patient and her spouse during the study period;

5. Patients with informed consent;

6. Predicted survival time is longer than 3 years.

Exclusion Criteria:

1. History of chronic degenerative, psychiatric, or neurologic disorder other than MG that can produce weakness or fatigue;
2. Patients who may have other diseases that may lead to eyelid drooping, peripheral muscle weakness or diplopia;
3. Age ≤18 years or ≥75 years;
4. Patients who have been taking glucocorticoids or associated immunosuppressants due to other immune system diseases;
5. Patients who cannot use immunosuppressants due to other chronic diseases;
6. Patients who are unable to cooperate with follow-up and self-assessment due to severe mental illness or cognitive impairment;
7. Pregnant women, lactating women and patients with fertility plans during the trial;
8. Patients who have suffered from severe infections or malignant tumors in the last 1 month and are unable to receive immunosuppressants treatments;
9. Patients who are not willing to cooperate with repeated frequency electrical stimulation tests and chest CT examinations;
10. Patients who are not willing to participate in this study;
11. Patients who are unable to sign informed consent;
12. Predicted survival time is shorter than 3 years;
13. Patients who are not suitable to participated in the trial after researchers' assessment.

Patients with newly-onset ocular myasthenia gravis