-: Hello, my name is
Collin McClelland. I'm a neuro-ophthalmologist from the
University of Minnesota.
And it's a great honor
to have another neuro-ophthalmologist with us today,
Dr. John Chen from the Mayo Clinic in Rochester, Minnesota.
He's an expert on optic neuritis. Welcome John.
-: Well, thanks Colin. Great to be here.
-: So we're going to be talking about optic neuritis today.
And, you know, old habits are hard to change.
So the optic neuritis treatment trial, John,
which began enrolling patients I think in the late 1980s,
it taught us that the most important test for a patient
with optic neuritis is actually an MRI of the brain to
evaluate for multiple sclerosis.
Additional blood testing really wasn't necessary,
and that treating patients
with steroids didn't change the long-term visual outcome
in patients with optic neuritis.
How has our understanding changed
and is that mantra from the ONTT still true today?
-: I think that mantra from the ONTT is very important
for your typical optic neuritis from multiple sclerosis,
but there's a couple entities
that we definitely have to think about
when you have a patient with optic neuritis. We have
to think about neuromyelitis optica, NMO spectrum disorder,
, and now a new entity which we didn't even know
existed at the time of the OTT,
which is MOG antibody-associated disease or MOGAD.
And the treatments
and prognosis for these diseases is completely different.
And so, we do have to think about these entities
now when you have a patient with optic neuritis.
-: Can you tell us a little bit more about MOGAD
and neuromyelitis optica spectrum disorder?
How are these diseases different than multiple sclerosis?
How is the optic neuritis different than the optic neuritis
we might see with multiple sclerosis?
-: Yeah, so neuromyelitis optica we've known about
for over a century, when Devic
and Gault first described that back in 1894,
and classically, these patients present
with severe optic neuritis and severe transverse myelitis.
And so their optic neuritis is going to be a little bit
different than MS in that it's often
going to be more severe.
Twenty percent of the time, actually, both optic nerves get
simultaneously involved, and the recovery is pretty poor.
And then for MOGAD, it also tends
to cause very severe optic neuritis at onset,
oftentimes bilateral, simultaneous 50% of the time.
They tend to have more optic disc edema.
But fortunately when you treat them
with corticosteroids, the recovery tends
to be a lot better than NMO.
And so it's not quite as visually disabling as NMO.
-: So would you recommend that every patient
with optic neuritis get treated
or, I'm sorry, get evaluated for an aquaporin-4 antibody
and a MOG antibody?
-: Certainly, actually, you know
because it changes your treatment
and prognosis. We are recommending for any patient
with optic neuritis,
unless it's very classic multiple sclerosis,
to be tested for the aquaporin-4 antibody
and the MOG antibody in the serum.
-: Great. And then for those who may be out there wondering,
you know, isn't the treatment
for all inflammatory demyelinating optic neuritis going to
be the same with corticosteroids,
why is it so important that we actually get a diagnosis
of MOGAD or NMO spectrum disorder as opposed
to the optic neuritis associated with MS?
-: That's a good question.
So with NMO, the prognosis is very poor.
So we're treating them with
corticosteroids as soon as we can.
And we typically add on a treatment called plasma exchange
when we actually take their blood,
filter out the pathologic antibodies,
and give them back the plasma.
And so it's an extra step that you need to do
because, again, up to 50% of patients
after a about of optic neuritis from NMO can end
up legally blind.
So, a lot worse prognosis than MS.
Where in the OTT we learned
that steroids just quickens recovery, doesn't
change the ultimate outcome,
it's probably not the case for NMO.
And we try to avoid that horrible prognosis.
For MOG and MOG antibody disease,
these attacks tend to be very steroid-responsive,
and the thought is that earlier treatment
leads to better outcomes.
And so, again, we're not really given the option of waiting
and watching to see how they do.
We're treating them with early high-dose corticosteroids
to try and quicken that recovery.
And then long-term, I think that's also very important.
With MS, you're going to treat them
with MS disease-modifying treatment.
With NMO, they need to be on some kind
of chronic long-term immunotherapy to prevent relapses,
because every single attack can be blinding.
And, then again, the treatments
for NMO are actually very different from the MS treatments.
The MS treatments are actually ineffective
or can potentially worsen the NMO,
but we now have some excellent FDA-approved medications
for NMO.
And for MOG long term, it's different as well.
If they've got a single attack with good recovery,
we're just kind of waiting and watching
because only 50% are going to relapse.
It's only once they have relapsing disease
that we put them on chronic immunotherapy.
And again, they're different from MS.
And so again, that's why it's so important when you have a
patient with optic neuritis to try
and determine which bucket are we going to put them in.
Is it going to be MS, NMO, or MOG, because prognosis
and treatment are completely different.
-: Well, I think you've done a great job today, John,
in educating everyone
that the mantra about optic neuritis has changed
significantly from the ONTT,
and we all appreciate your time today.
Thank you.
-: Thanks, Collin.