Please assess the completion status of the following clinical trial:

Trial Title: Natural History of Optic Neuritis

Study Design Characteristics:
- Allocation: None
- Intervention Model: None
- Observational Model: COHORT
- Primary Purpose: None
- Time Perspective: PROSPECTIVE
- Masking: None
- Phase: None
- Number of Arms: None

Eligibility Criteria:
* INCLUSION CRITERIA:~COHORT 1: Unilateral optic neuritis.~* Typical demyelinating optic neuritis based on the best clinical judgment of the investigators.~* Symptom onset within 46 weeks of enrollment OR patients with history of optic neuritis who were followed from symptom onset under a Neuroimmunology Branch natural history or screening protocol.~* For women of childbearing potential, willing to use acceptable forms of contraception (i.e. hormonal contraception (birth control pills, injected hormones, vaginal ring), intrauterine device, barrier methods (condom or diaphragm) with spermicide or they have undergone surgical sterilization (hysterectomy, tubal ligation, or vasectomy in a partner) for the study duration.~* Able to provide informed consent.~* Willing and able to participate in all aspects of the trial.~COHORT 2: Healthy volunteers.~* No medical history that would interfere with study result interpretation, in the best clinical judgment of the investigators.~* Age greater than or equal to 18 years and less than or equal to 50 years.~* Able to provide informed consent.~* Willing and able to participate in all aspects of the trial.~EXCLUSION CRITERIA:~* History of signs or symptoms suspicious for MS, in the best clinical judgment of the investigators.~* Pateints-Disease-modifying therapy for MS prior to the onset of the current episode of optic neuritis (excludes oral or intravenous glucocorticoids: Healthy Volunteers - Previous or current use of disease-modifying therapy for MS (excluding oral or intravenous glucocorticoids.~* Previous history of clinical optic neuritis or a systemic disease associated with optic neuritis (e.g. sarcoidosis, lymphoma).~* Current or prior optic neuropathy (e.g. trauma, ischemia, glaucoma, optic nerve drusen).~* Previous history of a retinal disease (e.g. diabetic retinopathy, retinal drusen) other than uveitis.~* Previous history of an ophthalmic disease that in the best judgment of the investigator could affect ophthalmic imaging results.~* Previous history of a systemic disease that may mimic MS (e.g. neurosyphilis, neurosarcoidosis, CNS ymphoma, Si(SqrRoot)(Delta)gren s syndrome).~* Previous history of a systemic disease that in the best judgment of the investigator could confound study outcome.~* Current use of a TNF-alpha inhibitor (e.g. etanercept).~* Habitual use of illicit drugs that in the best judgment of the investigators could confound study outcome.~* Pregnant or breast-feeding.~* Unwilling to co-enroll on a Neuroimmunology Branch natural history or screening protocol currently 89-N-0045.~* Contraindication to MRI scanning.

- Gender: ALL
- Minimum Age: 18 Years
- Maximum Age: 50 Years
- Healthy Volunteers: f

Study Arms:
- healthy volunteers (Type: None): age- and sex-matched to the participants with unilateral optic neuritis and a brain MRI suggestive of MS
- Patients with unilateral optic neuritis (Type: None): Recruitment will proceed until 10 participants with a brain MRI suggestive of MS (obtained at any time point during the study) have completed the study.

Based on this trial design, predict the completion outcome and termination type (if applicable).