VEP and ON question

[samandsprout]

Quick question about the relationship between the Visual Evoked Potentials test and Optic Neuritis:

Can you have ON but a negative VEP?  Or if you have a negative VEP, does that mean for sure you do not have ON?

I have had 2 negative VEP tests, but I really feel like something is wonky with my eyes.  Nothing obvious like blind spots or very blurry vision, but my vision just feels off & kind of fuzzy.  I had a normal exam and the eye dr (not the real kind, just the optometrist).  I'd like to put it down to staring at the computer all day for work, or just tired eyes from sleep deprivation (I have 2 kids under 3).  So, if my negative VEPs mean no ON, maybe I can stop obsessing about my eyes.  Thanks!
(I am not dx with MS yet - limbolander with lesions atypical for MS).

[samandsprout]

Thank you, this does answer my question.  You guys are awesome!  
I guess I will try to believe that I do not have / have not had ON.

[Eyesnlegs]

Thanks these are really useful resources - what surprised me about my result is that 5 years ago when I had ON for the 2nd time the MRI showed lesions on the optic nerve, I also have the pallor associated with ON and many, many other eye issues and yet this year my VEP was only borderline

I'm sure we could drive ourselves totally mad trying to research these things  lol. This is indeed a very curious and individual MonSter.

Thank you once more
Pat
x

[essdipity]

Here's a Google book result with more causes of abnormal VEP. It also says that even if the ON heals, the VEP will virtually always remain slow permanently.

http://books.google.com/books?id=vOQqyNhTDl0C&pg=PA481&lpg=PA481&dq=vep+abnormal+causes&source=bl&ots=LqWTi1j219&sig=ZpuTdw0NorASIrrCzuagmmu_Zfw&hl=en&ei=RhIpStGgB6W_twe5pYTBCA&sa=X&oi=book_result&ct=result&resnum=6

ess

[essdipity]

This is always a confusing subject. Some have abnormal VEPs with no history of ON. Some have attacks of what seems like it must be ON yet then have normal VEPs. There have been loads of discussions here, without a lot of clarification, it seems.

I wish I were knowledgeable, but not so. I did find a web site that explains the testing and offers alternative reasons for abnormal results on the test. But other than MS, these seem quite rare.

http://www.virtualmedicalcentre.com/healthinvestigations.asp?sid=52

I'll keep looking.

ess

[Eyesnlegs]

Just a thought would that abnormal VEP remain even when the ON has subsided?  

I ask as I have had 2 really severe bouts of ON, one 20 years ago and one 5 years ago and yert when my neuro finally decided to order a VEP this year I was told it was borderline?

Thanks
Pat

[PastorDan]

Posted a question on the Eye Care forum, and an MD answered.  He asserts that ON will always cause an abnormal VEP.  He also stressed that there are a host of causes for eye pain other than ON.  He suggested I see a neuro-ophthalmologist, which is who I saw last.   And so it continues....

[Erin0313]

  You would be very surprised to find out that lots of us suffer dry eyes and don't even know it. We blame the itchy feeling or blurred vision on a bunch of stuff like being tired etc.

Imagine a camera lens with a layer of dust on it and that's kind of what the dry eyes are. Your lens needs to be clean and clear to function best. I'm not sure if that was a good example - sorry best I could do.

Any way I was just trying to encourage you to try the drops for a few weeks (at least 3 times a day) and see if you notice improvement. It is quite easy and a benign way to feel better or rule out dry eyes as the culprit.

P.S. I'm not talking about visine but a lubricating drop that is preservative free. No rx needed but you can ask the pharmacist to find it for you.

Good luck
Erin :)

[samandsprout]

Just getting back to this....thanks, all, for the responses.

So, it sounds like one *could* have had ON in the past and yet have a negative VEP.  But what about if one is currently experiencing vision problems...if the current VEP is normal, can one be pretty sure that the current vision problems are not related to optic neuritis?  Or since I am not having blatant blurry vision or blind spots, could it still be some sort of residual from an old case of ON?  Not that I've had an obvious case of ON in the past, but maybe I had a slight case and never noticed?  I don't know, maybe I am grasping.

D - I am not on any meds that might cause fuzziness, but I am on a computer all day for work.  But my eyes don't always go all wonky at the end of the day, I can sometimes wake up with them already fuzzy/hazy.  

Erin - I suppose it could be dry eyes, but would I be able to tell easily that they are dry?  I just don't know.  Maybe I'll try eye drops and see what happens.  Thanks!

[Erin0313]

  I have had ON twice this year and my VEP was abnormal and the neuro opthamologist saw faded color and inflammation on my optic nerve.

  Have you ever had an episode where you lost your color vision or had intense pain when you moved your eyes (not your head) from side to side lasting for days?

  I was also wondering if you have allergies or dry eyes. I get kind of fuzzy vision when my eyes are dry. I use eye drops several times a day and an ointment at night to keep them moist and that really helps with the fuzzy yucky feeling. Maybe it's worth a try.

  Hope you get the answers you are looking for.

  Take care
  Erin :)

[Zacksmomi]

I have that totally wonky eye feeling too.  I just had a negative VEP and no visible lesions on my Brain MRI in the optic nerve.  
I am beginning to think mine is related to my meds like muscle relaxers.  So I am wondering if you may be on meds that cause eye fuzziness?
I also get alot worse when I am on the computer.

I do hope you feel better soon.
D

[sllowe]

Hi there

ON can cause a positive VEP.  The results could reveal some sort of a delay in the signal between the eyes and the brain.  But, you can also have had ON in the past and still have a negative VEP and a normal eye exam.  It just varies.

And, if the Optha didn't see inflammation on the optic nerve at the time of the exam, he/she could order a visual field test, or the VEP, etc....

Sorry I can't give you a solid either way :(

Be careful, the fuzzy wonky eyes make you even more tired!
ttys,
shell