Why did I temporarily loose vision in one eye?

Here is My Question:
I have MS and went blind in one eye for two days. Scariest thing ever. My doctor said this is common in MS. My questions are why is this common in MS? Why does this happen/what is going on in my body with the MS that would cause just one eye to loose sight (so weird), and is there anything I can do to prevent it from happening again??

Answer:
Losing vision in one eye can happen in MS due to a condition called optic neuritis.  The vision becomes blurry because of inflammation in the optic nerve (the optic nerve connects your eye to your brain).  With MS, the body's immune system can sometimes cause inappropriate inflammation and damage to the optic nerve leading to temporary vision loss. The immune system's attack on the optic nerve may flare up, and then the vision becomes blurry.  The vision returns back to normal (or almost back to normal)  when the inflammation resolves and the optic nerve has time to heal.  

Usually patients do not go completely blind but experience hazy or decreased vision associated with pain in the eye. 

The eye pain is typically worse with eye movements.  Usually the vision loss associated with optic neuritis will resolve after a few weeks but can improve more rapidly if treated with intravenous steroids.  

To prevent recurrent episodes of optic neuritis, patients with MS should be on some form of immunomodulatory therapy that is FDA approved for relapsing multiple sclerosis (for example, interferon therapy, glatiramer acetate, natalizumab, or one of the several pills now approved for MS). To figure out which medicaiton is best for you, consultation with your neurologist or an MS specialist is required.

Finally, not all forms of transient vision loss are due to multiple sclerosis.  If you or your neurologist are not sure what caused your vision loss, consider seeing a neuro-ophthalmologist for further evaluation."

Sincerely,

Benjamin Osborne, MD
Associate Professor
Departments of Neurology and Ophthalmology
Georgetown University Hospital