RAPD or Relative Affect Pupillary Defect

[MrsOwl]

Hi, at my last consultation my neurologist said that he detected a subtle RAPD which is when one eye doesn't respond to light the same way as the other eye. On that basis and also on the basis of other symptoms (left eye film on/off with temple and eye pain) he suggested that I might be having optic neuritis and he is sending me to have visuals evoked potentials done this month.

My question is - have any of you with ON been told that you also have RAPD?

These eye problems terrify me!

[MSer102]

An RAPD just goes with the territory with ON. Doctors often don't even mention it because it isn't a doctors job to give a play by play description of everything they do or of everything they look for and what everything they see means. Some doctors will take the time to explain, some won't.

Until I finally got a good neurologist, none of my neuros ever said anything about my RAPD. I found out later it was because none of them were sharp enough to even notice it. My eye doctors were the ones who talked to me about it.

An RAPD is a primary sign of an optic nerve problem. It isn't specific just to ON or MS. Any kind of significant optic nerve damage will cause an RAPD.

Your post is interesting to me because it shows one of the ways that neurologists misunderstand the visual signs that go with MS. An RAPD and abnormal VEP and abnormal visual fields can persist long after the active case of optic neuritis is gone. So your neurologist doesn't have any way to know how recent the damage is that caused your RAPD and possibly abnormal VEP.

So I think it's important that you and everybody else who is reading this thread knows that abnormal results do not mean that the ON is current or active. It's surprising how many people - apparently including neurologists - think that a VEP is an "ON test". It isn't.

For the most complete care possible, it's a better idea for you to be assessed by an ophthalmologist who can actually do the proper eye examination to tell you whether you are having an active episode of ON or if you have leftover signs from a previous/inactive case of ON or if your RAPD might have come from some other cause. Your neurologist has no way to do the tests necessary to actually know what's causing your vision and eye issues. It's not unreasonable to believe that ON is a likely cause of certain signs and symptoms in a person with MS, but it's assuming far too much to think that a definite answer is going to come from just a pupil test and a VEP.

I do have to give kudos to your neurologist, though, for being able to recognize and RAPD. As I said, mine - and there were several - didn't pick mine up. And it's good that your neuro sent you for a VEP. But if your neuro were concerned about your total well being, he would also have sent you to an ophthalmologist for a proper, complete eye exam and documentation.

I'm visually impaired from many episodes of ON so I know how scary these eye issues can be. But I also appreciate how important it is to keep things in perspective. I remember reading a post somewhere from someone who got freaked out that the pupil thing has a name and she said she was "suffering" from an RAPD. Apparently she was suffering psychologically, but the pupil abnormality itself is harmless and nothing to be afraid of.

What's important is that an RAPD is a sign of a problem and it's the problem that needs to be addressed, not the RAPD. And because of that, a lot of doctors won't even mention an RAPD and will go straight to the discussion of what the underlying issue is. There isn't any medical significance to whether the doctor mentions it or not. I think the significance of whether or not an RAPD is mentioned is that it gives a clue to what the doctor's "chairside manner" is.

[OhioKris]

My eye dr also found I have a pupil defect when going thru ON this past summer. Even tho vision cleared up, pupil defect remains. Now having new vision loss in both eyes. MRI found lesions on right and left optic track so off to neuro ophthalmologist I go. Can't imagine what they can do to help???

[MSer102]

The neuro-ophthalmologist might not do anything that helps directly. The major thing they do to help is to know what's going on, how to test for it, how to document it, and what it means to a person's overall visual function.

My neuro-ophthalmologist has me do different visual field patterns than the general ophthalmologists did (when they bothered to have me do a visual field test at all) because he knows that neuro issues are better found and followed using different tests. And he knows how to interpret my test results because he sees visual field results like mine all the time. General ophthalmologists don't see them as often so don't have the same kind of experience interpreting them.

My neuro-ophthalmologist used to have me do OCT readings until I bottomed out and there wasn't any point in doing them anymore. None of the general ophthalmologists I saw every had me do an OCT. My neuro-ophthalmologist knows what the different OCT abnormalities mean because he's used to seeing what they look like in different neurological issues. General ophthalmologists don't get to see enough neurological OCT's to know how to interpret the subtle differences between them.

My neuro-ophthalmologist has me do a color test with each eye every time I go in. None of the general ophthalmologists I saw ever had me do a color test.

My neuro-ophthalmologist had me do contrast sensitivity tests until I bottomed out and couldn't tell the difference between the letters and the patterns anymore. None of the general ophthalmologists I saw ever had me do a contrast test.

My neuro-ophthalmologists (I've had a couple of great ones) know the difference between my severely atrophied optic nerves from repeated bouts of optic neuritis and glaucoma. The general ophthalmologists I saw didn't even know that repeated optic neuritis can cause the kind of severe atrophy I have and didn't know what to do. I even had one general ophthalmologist who insisted that I'd never even had a single episode of optic neuritis and only had glaucoma, in spite of years of ophthalmology records that documented my cases of optic neuritis. There's no evidence that I've ever had glaucoma. I've had none of that nonsense with my neuro-ophthalmologists.

Just the fact that the neuro-ophthalmologist knows what they're looking at and what to do and not do makes them very helpful. Far more helpful than a neurologist or general ophthalmologist who doesn't have a clue what they're looking at.

[OhioKris]

Your reply was most helpful, thank you! My regular eye Dr insisted my sudden shift in eye testing was NOT MS related. I wear contacts mostly for near sightedness. Normal for past 5 years is 3.75 strength. It jumped to 4.50 and 4.75 in two months time and she couldn't completely correct me. MRI did show spots on right and left optic tracts but said not enhancing with contrast. Does that indicate they are old? Looking forward to seeing the neuro ophthalmologist and hoping he can give me a better rx to help me see. Havjng huge problems at work with computer.