Optic neuritis and lack of red eye in photos

[Joiedecour]

Does anyone know how an eye with ON will react in dark to flash photography? For example if there is one red eye with enlarged pupil and one normal looking eye, would the ON affected eye be the normal looking one? Or is this completely irrelevant to optic neuritis?

[Joiedecour]

Hi JJ,
You give SUCH great answers...not sure I understand it all, but wow, such detail. Thank you. As you can probably tell I am trying to work stuff out without bugging the docs, and also saving some money, but probably I should just go to an opthamologist instead of trying to coordinate between  eye doc and neuro. I had eye pain all last week, but nothing major in terms of weird vision.
My eye doc's office eventually sent my records to neuro's office, and they've been "on the doctor's desk" since March 17, and they'll call me if they think there's a problem - those were the abnormal visual fields. So I am still waiting.
I do have several photos which look strange to me though, although I still don't know where to start in interpreting them : ) Guess that's why we need docs, right?!
Thanks, JdC

[supermum_ms]

I don't know how ON will react in dark to flash photography 'specifically', red eye from a camera flash is the reflection off of the retina and its a red colour from the blood vessels nourishing the eye.  The pupils constrict (get smaller) with bright light and dilate (enlarge) to let in more light, with photography the size of the pupil is generally to do with amount of light in the environment the person is in, and often photo's will catch enlarged pupils and the reflected redness because the pupil was larger when the photo was taken.

With ON, what can happen is called "afferent pupillary defect (APD), also referred to as Marcus Gunn Pupil" and when a light is shone into the eyes, the eye with ON will abnormally respond by dilating (enlarging) instead of what normally happen's with light which is to constrict (get smaller) and this is because the brain isn't getting the signals properly in the eye with the optic nerve damage.

So from my understanding, if the photograph was showing one red 'enlarged dilated pupil' and the other pupil 'noticeably smaller' and not red, if there was an abnormality (different pupil size isnt always abnormal - Physiologic anisocoria) it would probably still depend on the amount of light in the environment to work out which eye was reacting abnormally. The red enlarged pupil could be responding perfectly normally and the smaller pupil is the one that's reacting abnormally to the amount of light.

Keep in mind that ON can abnormally respond in the pupil response light tests, but the flash from photographs is not the same thing, and wont produce the same effect as the light testing does. The size of the pupil reflects the amount of light of the environment, and if every time you shine a light at your eyes it produces one pupil to respond abnormally and the other normally, then that would be more telling i'd think than a one off photo.

Cheers........JJ

ps hope that made sense lol