The purpose of this study is to collect preliminary data on retinal nerve fiber layer and ganglion cell layer damage in multiple sclerosis (MS) patients, using optical coherence tomography (OCT). For this study the Zeiss Cirrus OCT Imaging System will be used. The same system will be used consistently for the duration of the study.

Hypothesis: Multiple sclerosis results in axonal degeneration which can be assessed objectively and non-invasively by serial OCT measurements of the RNFL and GCL.

This will be a prospective cross-sectional, non-interventional study; total recruitment will be 200 subjects. Recruitment will be stratified to enroll at least 50 subjects currently taking Lemtrada and 50 subjects with a documented diagnosis of ON. The study will enroll subjects primarily from practices in the Tampa Bay Area and adjacent counties. It is a planned non-interventional study; subjects will be followed by their neurologist and the study ophthalmologist and will receive standard of care. All subjects will have the ophthalmological examination and diagnostic measures, by the Principal Investigator, Dr. Grace Levy-Clarke, at Tampa Bay Uveitis Center.

Study Duration: The study duration will be 24 months, with an interim analysis at 50% recruitment status.

There are two primary aims of this longitudinal observational study:

1. To determine whether atrophy within specific retinal layers over time is associated with clinical neurological progression of MS
2. To determine whether an ON history affects the relationship described in aim # 1

Eye Exam: Subject will have an eye exam, including:

Visual Acuity Testing Color Vision Testing Automated perimetry/Peripheral Vision Testing Completing the National Eye Institute Visual Functioning Questionnaire (NEI/VFQ) Slit Lamp Examination Measurement of Intraocular Pressure (IOP) Dilated Fundus Examination (Ophthalmoscopy) Fundus Photography Optical Coherence Tomography: RNFL and Macular OCT

Neurologic Assessments: Must be performed no more than 60 days prior to screening/assessment Day 0 Ophthalmic Assessments

Inclusion Criteria:

• Age 18 or older
• Pregnant women will be excluded by self declaration
• Male or female
• A diagnosis of MS, that meets the 2010 Revised McDonald Diagnostic Criteria
• A visual acuity of 20/400 or better in at least one eye

Exclusion Criteria:

• Any ocular disease than prevents assessment of the optic nerve and macula by OCT
• Advance glaucoma with optic nerve damage
• Any optic neuropathy not diagnosed as ON associated with MS
• A diagnosis of Macular Degeneration
• Any previous ocular trauma
• Any medical history of a cerebrovascular accident
• Any planned ocular or systemic elective surgery during study duration
• Any contraindication to a comprehensive dilated ophthalmic examination
• Inability to give informed consent

The study population will include patients meeting the diagnostic criteria of multiple sclerosis. Patients will be 18 years or older and pregnant women will be excluded. male and fmale patients will be recruited.