Often times an X-ray and CT are used to confirm if the problem is neurogenic and not physical. ON can certainly be a possibility and ON can be a separate problem than MS or it can eventually lead to MS.
If there are concerns, there should be no reason your PC cannot order the MRI. Ask for an MRI with and without contrast of your head and c-spine. If ON is the primary possibility, I would encourage you to seek the counsel of a neuro-ophthalmologist. If you have ON, the ophthalmologist should be able to tell you even 7 months later. Most people who have had ON will have some kind of residual damage and this will be seen.
If you are having tests run, typically you would have:
1. A routine eye exam. Your eye doctor will check your vision and your ability to perceive different colors.
2. Ophthalmoscopy. A bright light is shined into your eye and the doctor examines the structures at the back of your eye to evaluate the optic disk, which is the area where the optic nerve enters the retina in your eye. For about 1/3rd of people with ON the optic disk becomes swollen.
3. Pupillary light reaction test. Your doctor may move a flashlight in front of your eyes to see how your pupils respond when they're exposed to bright light. Pupils in eyes affected by optic neuritis don't constrict as much as those in healthy eyes do when stimulated by light. If you have been using eye drops, let your doctor know because this can affect some results.
Other tests you may have include:
4. VEP test (Visual evoked potentials test). To perform this test, you sit before a screen on which an alternating checkerboard pattern is displayed. Attached to your head are wires with small patches to record your brain's responses to the visual stimuli. This type of test is able to detect the slowing of electrical conduction resulting from damaged areas on the optic nerve. The VEP is quite sensitive and can determine the slightest of changes. The test is non-invasive. The worst part is not shampooing the day before the test! My last VEP showed there were problems and it led to discovering active lesions in my thoracic spine.
5. Magnetic resonance imaging (MRI) scan. You should have the MRI with and without contrast. The neuro-ophthalmologist can order the MRI.
6. Blood tests. A blood test is available to check for antibodies for neuromyelitis optica. An erythrocyte sedimentation rate (“ESR”) blood test is used to detect inflammation occurring in your body. This test may help determine whether optic neuritis is caused by inflamed cranial arteries (cranial arteritis). Blood tests are also used to rule out diabetes.