June 25, 2025 • 53 mins
Fuchs Dystrophy is an important condition to be aware before operating on any patient. Cataract surgery, in particular, can cause someone with otherwise asymptomatic Fuchs to develop debilitating corneal edema. Then again, not everyone with Fuchs Dystrophy is destined to develop corneal swelling. So how do we determine which patients are at increased risk of corneal decompensation? How do we know which Fuchs patients warrant combined cataract surgery and endothelial keratoplasty? And as an alternative to corneal transplantation, how do procedures such as DSO or potentially even endothelial cell injection, factor into our treatment of the condition? Dr. Guillermo Rocha joins the podcast.
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Episode Transcript
Available transcripts are automatically generated. Complete accuracy is not guaranteed.
Speaker 1 (00:09):
Hey everybody, I'm Zaeo Mednik and welcome to another episode
of Blindspot. This episode is sponsored by THEA Pharma Canada.
THEA Pharma Canada is the Canadian subsidiary of THEA, Europe's
leading pioneering and innovative eye health brand. Founded in nineteen
ninety four by Henri Chibre. With five generations of history,
the Chibret family has been dedicated to I care for
(00:30):
more than one hundred and fifty years. Their commitment to
improving lives is born of their pioneering spirit. They continue
to lead the worldwide preservative free movement in eye care.
They've created innovative delivery systems. They've focused on making products
accessible and cost effective for patients. They live this mission
every day because everyone should have the same opportunities to
see the world through healthy eyes. So thank you THEO
(00:53):
Pharmer Canada for supporting blind Spot. Fuchs dystrophy is an
important condition to be aware of before operating on any
patient cataract surgery in particular, or it can cause someone
with otherwise asymptomatic Fuchs to develop debilitating corneal edema. And again,
not everyone with Fuchs dystrophy is destined to develop corneal swelling.
(01:13):
So how do we determine which patients are at increased
risk of corneal decompensation? How do we know which Fuchs
patients warrant combined cataract surgery and endothelial carotoplasty and as
an alternative to corneal transplantation. How do procedures such as
DSO or potentially even endothelial cell injection factor into our
treatment of the condition. I'm joined today by doctor Germo Rocha.
(01:37):
Doctor Germo roach is the chair of the Department of
Ophthalmology and Visual Sciences at McGill University. Native of Mexico,
doctor Roche received his MD from University dad to Annawak
Medical School in Mexico City, after which he completed an
internship at the American British Caldre Hospital. He began his
postgraduate training as a first year resident in ophthalmology in
Mexico City and then came to mcguil for a research
(01:59):
fellowship in ocular immunology in the departments of Ophthalmology and
Microbiology and Immunology, followed by ophthalmology residency training in the
Department of Ophthalmology. After McGill, he studied at the University
of South Florida and Tampa Bay, where he completed a
fellowship in a research scholarship in Cornea and external disease.
For many years he was a professor at the Faculty
of Medicine at the University of Manitoba, and for the
(02:21):
past two decades has been the medical director of the
Ocular Microsurgery and Laser Center in Brandon, Manitoba. He was
president of the Canadian Ophthalmology Society from twenty sixteen to
twenty eighteen and has been an active lecturer and presenter
and has participated in more than one hundred and fifty regional,
national and international leadership conferences over the course of his career.
(02:41):
He is now Chair of the Department of Ophthalmology and
Visual Sciences at McGill University. Doctor Rochell, Welcome to the podcast.
Thank you so much for joining me.
Speaker 2 (02:48):
Thank you so much, Assail. It's great to see you.
I still remember when I met you. You were a
medical student, a very bright medical study gay. But I'd
so great to see how you been branching out in
different expert areas of expertise. I would say, so well, great,
par Thank you.
Speaker 3 (03:07):
It's an absolute pleasure.
Speaker 1 (03:08):
You were one of my first and primary mentors in
ophthalmology and one of the reasons I.
Speaker 3 (03:13):
Wanted to get into cornea. Sir.
Speaker 1 (03:15):
I still remember you doing the first PKP that I
saw way back when and thinking, Wow, that's that's really cool.
And I did one today, so we've come we've come
full circle.
Speaker 2 (03:25):
So circle, that's amazing. That's amazing. No pun intended, right
with a round PKP.
Speaker 1 (03:29):
Yes, no pun intended. I remember the question you asked me.
You said, what's the most important stitch? As you were yeah,
it was a leading question. You were basically giving me
the answer as you were putting in your second stitch
of the PKP. So anyhow, we're talking about fuchs today,
which is a condition where typically you don't need a
PKP because we've become so adept at all of these
(03:50):
new kind of technologies and there's been so much research
advancement over the last fifteen twenty years. Fuchs is a
topic that when we were chatting, you said, I think
that could be an interesting episode, and I certainly think
it's obviously relevant to cornea specialists, but to general optomologists
and optometrists listening to this as well, because there's a
lot of patients who come through the clinic with Fuchs dystrophe,
(04:13):
and if you're not a cornea specialist, and even if
you are in certain cases, it's easy to wonder. Okay,
so how am I supposed to deal with this? How
am I supposed to cancel the patient? What surgery am
I supposed to do? When do they need to see
a cornea specialist to get started? Most people probably know this,
but just give a brief overview, perhaps of what exactly
Fuchs dystrophe is.
Speaker 2 (04:34):
Okay, yeah, I mean it's a topic that has become
almost a passion for me. Fuchs dystrophy affects the inner
layer of the cornia, the innermost layer of the cornea,
which is the endothelium. So as we know, even when
I finished aphalmology, since that time, a lot of things
have changed in cornia, including the fact that we grew up,
(04:55):
I should say, with five layers on the cornia, but
now we've added one layer, the dua layer. And I
remember when I finished my training in nineteen ninety five
and went on to my fellowship. I remember sitting with
one of my mentors and he told me, you know,
nothing has changed in corneal surgery in a long, long time,
(05:16):
and so what has changed in all of these years
is our different perception of fukes. In the beginning, we
would look at a cornea and the sole treatment was
a penetrating carratoplasty and that was it. But as we
learned to understand the different layers of the cornea, and
as we had developments in I think it's three things
(05:36):
that we've seen. Developments in technology, developments in biology in
our knowledge of the biology of tissues, and also developments
in pharmacology. We started splitting that cornea, which is barely
a half a millimeter, into different layers, not just for
the purposes of anatomy, but for the purposes of treatment
(05:58):
in a more customized way. So Fuchs dystrophe has become
very important because for years a condition that affects the
inner layer of the cornea, only we were actually changing
the whole thing, you know, and that we all knew it.
It doesn't make sense. Fuchs dystrophe is a hereditary condition.
(06:19):
It's an autosomal dominant condition which as the cells begin
to become affected, they produce these X crecenses, which we
call gute and they can be seen clinically and they
can be seen on specular microscopy. So as the cells
start loosing their pumping sites, they're pumping mechanisms, then the
(06:40):
water from the aqueous humor begins to kind of percolate
into the cornea, because as we know, cornea's almost like
a sponge, it's drawing water into it. And so as
the endothelial function declines, then the swelling of the cornea
becomes more and more severe, and we go through several stages,
four stages where you begin to have some symptoms during
(07:04):
the morning, the patient cannot see as well, until maybe
a couple of hours later you begin to see problems
with glare or halo, especially when they're driving at night,
and slowly the cornea becomes more edematous and it's more
persistent throughout the day. Eventually, if it's not treated in
a timely manner, they can develop bully, which rupture and
(07:26):
cause pain. And these ruptured bully and persistent pain and
persistent edema result in corneal scarring. And it was usually
at that time when we saw the condition being more
and more advanced that we would say, well, it's now
time to change the full cornia for you so that
(07:47):
you can see again.
Speaker 1 (07:49):
And the way you even explain how the decision was
made when you would do surgery, obviously back then was
different than it is now because beforehand, you weren't going
to take somebody who maybe had a little bit of
edema or just some glare from the gutata and say
let's give you a PKP, which is a huge procedure,
whereas now if somebody is a little bit less symptomatic,
(08:10):
still symptomatic enough, that's a discussion and we'll talk about
some of the criteria. You might be a little quicker
to say, hey, maybe we should treat that. In my mind,
there's kind of two buckets of symptoms. One is gutata
related symptoms where some patients might get glare or they
might just find something's off about the quality of their vision.
(08:30):
And then there are the symptoms that are related to
the development of edema.
Speaker 3 (08:35):
Is that a fair way to look at it.
Speaker 2 (08:37):
I think that's a great way to separate the two
categories of symptoms, and it is also a great way
to kind of discuss the changes in assumptions that we
used to make, and a paradigm shift in terms of
how we treat the symptoms. So, for example, in terms
of assumptions, we used to say, well, the patient has
(08:59):
Fuchs district. Now the cornea is thick, so what level
is it thick enough that we should do a combined
or a triple procedure? And so some people use the
magic number of six hundred and forty microns for example,
and six hundred and twenty five maybe it's a little
bit doubtful. We'll see. Another assumption that we always made
is that if we did a triple procedure, well, magically somehow,
(09:22):
we always calculated those lenses with forty three point five
diopters of k readings or something similar, of course, assuming
that that was going to be our end result. And
so those were two assumptions that were made in the past,
and so you're absolutely right. We used to wait until
the cornea was significantly symptomatic or the patient was significantly
(09:44):
symptomatic to start acting on that. So now the paradigm shift.
So a lot of the things that I'm doing now
I never thought I would be doing in my practice. So,
for example, one thing I don't look at necessarily is
corneli sickness, because we now know that the range of
normal corneal thickness can be from between four hundred and
(10:07):
eighty microns to six hundred and twenty microns two standard deviations,
and so we don't know when that cornea started. Did
it start at four seventy, did it start at five
twenty five? And so what is the increase? The second
thing is we see a lot of patients with refractive surgery,
So how do we know that those cornias that we're
now seeing maybe as normal are not really thin corneas
(10:31):
from previous laser refractive surgery and now they're thick. Another
thing I don't do anymore is to build my medical
decision or my surgical decision, is to look at endothelial
cell counts. So speculator microscopy really is kind of passe
in the sense of deciding what type of procedure I'm
(10:51):
going to be doing. So then what do we do now?
And you're exactly on point. I've had patients who have
twenty thirty vision, twenty twenty five vision, but with central
clumps of corneal gute and they just cannot function especially
if they're driving at night, they're driving and they have
young kids. I remember operating on a young patient who
(11:13):
had to drive their kids to hockey and she just
could not function, and so we went ahead and did
surgery on something that many years ago would have been inconceivable.
You know, a vision of twenty thirty for that. And
the other aspect is the symptoms. So if somebody has
a lot of problems with symptoms and they cannot function
regardless of their vision, and if they have cornea, gutata
(11:36):
and fuchs, then it's a good time to discuss surgery
for them.
Speaker 1 (11:41):
A few comments, they are on some rearly excellent points.
So for bochymetry, of course we don't know what the
baseline is, right, so five point forty is kind of
thought to be the average corneal thickness, so six forty
was thought to be.
Speaker 3 (11:54):
If it's above six forty.
Speaker 1 (11:56):
Then that's one of the reasons why you would do
a triple procedure. For those not familiar with that term,
that means doing cataract surgery and a dsect or a
DMC at the same time.
Speaker 3 (12:05):
Yeah. For me, for example, po chemmetry is more useful.
Speaker 1 (12:08):
I got a consult the other day where it wasn't
necessarily about Fuchs, but it was is there an issue
with this one eye? Is it swollen? And it didn't
look swollen, and it was almost asymmetry between the two eyes.
That's where I sometimes find it to be most useful.
Or if there's symptoms in one eye but not symptoms
in the other eye, then maybe that the chemmetry will
give me some more value. Why have you said that
(12:30):
spec microscopy is a little bit passe? Is that because
we tend to look more now at the symptoms that
they're presenting with and the severity of those symptoms. So
if you know it's Fuchs, and you know that they're
bothered by it, then it doesn't really matter what the
specula microscopy shows you in terms of cell density.
Speaker 2 (12:51):
Yes, in park Yes. The other part is that because
the cornnia gutata is pushing the endothelial cells away, you
really cannot measure adequately the concentration or the density of
cells in the endothelium. And the other thing is that, Okay,
if we're talking about imaging, should we be looking at
(13:13):
other aspects that are more sort of clinically relevant In
our planning and our decision making during Fuchs dystrophee assessment.
And so one of the biggest advances I think for
my practice and one that has really proven to be
a significant contribution are the studies on using shine flug imaging.
(13:34):
And the original reports specifically are for Pentacam on shineflug imaging.
We're developed at the Mayo Clinic by Sanjay Patel. So
what they did was assess shine flug and as you know,
just maybe for our listeners, So shineflug imaging is a
very very high quality, a high definition photography which takes
(13:55):
twenty five or fifty rings of images through throughout the cornea,
providing us information on anterior corneal curvature, anterior elevation, posterior curvature,
posterior elevation, as well as cornial thickness and also now densitometry.
And so the original publications on shine flug imaging for
(14:19):
a Fuge dystrophe looked at if you have certain criteria
over sixty months, over five years, what are the risk
factors for those cornias decompensating enough that you would need
a corneal transplant. And so the three criteria are very simple,
very straightforward, and I actually like I always get a
(14:40):
pentacon on all my paract consultations and obviously FUS patients
as well, and so we look at and review these
with the residents. And so the first one is a
displacement of the thinnest point. And so one could assume
that normally the thinnest point is in the center, and
as you begin to develop a d that thinnest point
(15:01):
is displaced somewhere. It could be nasally temporarily. Second thing is,
as you look at the rings of pachymetry on the cornea,
they're usually concentric, you know, they're very nice and round
and concentric. But as Fuchs develops these rings these isopacks
become not round and concentric, but irregular and distorted. So
(15:23):
second criteria and the third criteria is that as you
begin to get swelling on the cornea, if you think
of caratoconus, you see posterior elevation pushing forward. Well, it's
the opposite in Fuchs because you see posterior depression on
shine flug imaging. And so the three criterias to summarize
(15:44):
are displacement of the thinnest point of the cornea second
irregularity of the isopacks and third is a posterior depression.
And if you have zero criteria then you really have
almost zero risk of decompensating at five years. If you
have one criteria, maybe about twenty percent chance of decompensating.
(16:08):
And if you have two or three then the rates
go pretty high, up to about seventy five percent risk
of decompensating. And so for me, now, yes, I've made
the diagnosis. Yes the patient has symptoms they want to
see better. Now let's look at the shine flug imaging.
If they have two criteria or three criteria, there's no
(16:29):
question I will offer combined d MACH triple procedure, and
if not, I will do cataract surgery alone. And I'll
just be extra careful with protecting the endothelium using a
soft shell technique for example, making sure I'm working in
the bag. And these patients usually do very well.
Speaker 3 (16:48):
That really is quite a paradigm shift.
Speaker 1 (16:51):
And I remember in residency what I had learned was
like we talked about cases in which we would say,
you know what, you shouldn't just get the cataract taken it.
You should get the DMAC or d SC as well,
Like we said greater than six hundred microunds pochemetry. The
other one was mourning blurriness or symptoms. And then if
you see clinical edemo on exam, Now, if they've got
(17:12):
significant morning blurriness or they've got clinical edema on exam,
are you going to be as reliant on the pentacam
or shineslung imaging or are you more so just going
to say at that point kind of regardless what that
shine flug imaging shows, and I'm guessing it probably would
show something. Those symptoms of morning blurriness and the fact
that you have clinical edema, those are quite predictive that
(17:33):
you really do need some sort of endothelia creatoplasty regardless
of what the shine slung imaging is showing.
Speaker 2 (17:40):
Yeah, that's that's a great that's a great point, Zal
because ultimately what we are is treating our patients. Right, Ultimately,
we're not treating an image, We're not treating one single thing.
And I think there's there's usually in what we do
as surgeons and as physicians is we have the science
of everything. We try to be as signific and evidence
(18:01):
based on what we do. But then there's also the
art portion, the sitting down with the patient and asking
them their comfort level, how are they functioning throughout the day,
and if those symptoms and the poor function they have
to enjoy their daily activities kind of corresponds to what
you're seeing in terms of the Fuchs disease in their
particular eye. Definitely, I would go ahead and just do
(18:24):
the and do the endothelial caratoplasty at that point.
Speaker 3 (18:28):
It's really really useful what you're saying.
Speaker 1 (18:30):
And that's not something I've done looking at the shine
plunk imaging, but I'm going to do that more frequently
because there are a lot of cases where I am
kind of fifty to fifty and I can't really tell
is that symptom a cataract symptom?
Speaker 3 (18:41):
Is that?
Speaker 1 (18:41):
Is that a morning blurriness type symptom? Is it kutata
or is it just the cataract. They don't really have
any edema that I'm seeing on exam, and it's tough,
and I kind of say to the patient, I don't
really know.
Speaker 3 (18:51):
I said, it's up to you.
Speaker 1 (18:52):
Sometimes we can try doing the cataract surgery and then
there's a chance to Corney is going to decompensate, or
we could do them both at once, and I think
that's reasonable. But what you're saying is we have some
better metrics now that can actually tell the patient. Hey,
wait a second, you know what, Right now, things look
pretty fine. Maybe I'm fifty to fifty based on clinical
(19:13):
exam and traditional criteria, but let's look at your pentacam
here or your shine flung imaging, whatever you're using, and
actually you are at higher risk. You probably should get
it because your risk of converting in five years is
quite high, which which brings me to my other question.
There is a proportion of patients here correct that will
not necessarily progress. I think some people when they hear
(19:36):
they have Fuchs, they kind of freak out or they're
told by somebody, you're definitely going to need a corneal transplant.
But there is certainly a contingent of patients who might
too fine with cataracts surgery alone, depending on their life expectancy,
and not need that corneal procedure.
Speaker 2 (19:50):
Absolutely, absolutely right, And that's why you know, it depends
on the degree of cataract. If the cataract is more
advanced and they have Fuchs and they have two criteria,
I would be more prone to offering a combined procedure
that they than if they have two criteria and a
milder cataract. You know, And sometimes it's just you've seen
(20:11):
it right, zeal. When you're starting to decimate strip and
you peel you can see the irregularity of the gute,
and as you peel it off, the vision for you
as a surgeon becomes clearer into the anterior chamber, so
you can understand that, oh my gosh, like this this patient,
even though they were seeing twenty twenty five in my room,
(20:32):
they're probably having an awful time functioning in real life.
So there's a lot of art in that in our
decision making.
Speaker 1 (20:40):
One thing you said earlier was that you used to
back in the day, I guess, for lack of a
better term, you used to assume a forty three point
five diopter cornea. Now, when the cornea starts swelling, obviously
the biometry results are going to not be super accurate.
So is there a benefit in certain situations. It's weird
(21:05):
because with cataract surgery, I usually say let's.
Speaker 3 (21:07):
Wait until you're more symptomatic.
Speaker 1 (21:08):
That's my tendency, which is kind of what we're taught, right,
But with Fuchs, if you're going to be doing a
combined d MECH in cataract surgery, is there an advantage
to saying, you know what, let's do it a little
bit sooner before your biometry is off and we're potentially
putting a lens in that doesn't match your eye.
Speaker 2 (21:26):
Well, As you bring up the topic, I think of
what I always say to the general ophthalmologists when seeing
patients with Fuchs, my recommendation in these patients. So I
have several recommendations on these patients, especially if they're not
going to go for a combined procedure. The first thing is,
as soon as you see someone with Fuchs, get a topography,
(21:49):
preferably a shine flow image in and also get a
biometry at your baseline biometry. I have planned years later
even touric lenses in some of these paties based on
the original biometry before the cornea became more edematous, and
the results can be very very good. So you are right,
(22:09):
we are not going to rely perhaps on the more
advanced if that's all we have, that's all we have.
Once they get more edema, you do a biometry. Yeah
it may be good, maybe not so good. But I
try to get and to try to instill the message
that we should get biometry as soon as you make
the diagnosis of fuchs and then keep it there and
(22:31):
see how it changes through the years, as long as
the as well as the shine flow. Second recommendation is
if you think that well there's fuchs, they might decompensate.
Aside from your protection of the endothelium, some people use
BSS plus, some use the soft shell technique. Target your
lens to a result of around minus zero point seventy
(22:53):
five diopters, because after endothelial caratoplasty there can be a shift,
a hyperopic shift, and it's usually of around point seventy
five to one diopter, So compensating for that is also
a good IDEA third recommendation I have is make a
smaller capsule of rexis because by the time, let's say,
(23:13):
if the patient is referred onwards to a cornea surgeon
and we're going to do endothelial keratoplasty, we're going to
be messing with the lens and putting error on this
and manipulating and tapping the eye. We don't want a
lens that's kind of smaller than the opening of the
rexes and sort of the lens coming forward, because that
may cause other problems. And the final fourth recommendation I
(23:36):
have is if the patient comes back they had a
successful cataract surgery, they were doing okay, but now the
vision is going down all right? Is it the fuchs
or is it a posterior capsular opacity. And my suggestion
is don't do a Yag capsulotomy until assessed by a
corneal surgeon, because I would be more prone to doing
(24:00):
a d MECH for example, or a d SC and
these eyes rather than proceeding with a capsule ootomy and
then having the vitrios migrate forward as we're doing our
maneuvers during surgery.
Speaker 1 (24:12):
Those are all really really practical pieces of advice, many
of which I did not know. I'm guessing that means
at least other non cornial specialists, I probably didn't know those.
I don't want to speak for other corneal specialists. One
thing I want to ask you about is a stigmatism.
I've had a couple of cases recently where I've had
a patient with a moderate amount of a stigmatism enough
(24:32):
where it's not just one diopter where I would say,
you know, I really do think you'll get a much
better result with a toric lens. But I'm recommending that
we do a combined FACO d MECH or a FACO
d SC, But you can't really do that with a
touric lens. You can't, or for me, at least, I
find it's pretty tough to put a toric lens in
an eye at the same time I'm doing a d
(24:53):
MECH because as you're, like you just said, maneuvering the
anterior chamber.
Speaker 3 (24:58):
Things are kind of going up and down.
Speaker 1 (25:00):
The toric lenses probably going to shift, and you might
not get it positioned in the axis that's intended. What's
your approach for these patients? Do you ever put a
toric lens in? Maybe maybe I should be putting toric
lenses in during a triple procedure and you're able to
position it properly, would you just tell the patient listen,
(25:21):
unfortunately your eye is not a normal eye.
Speaker 3 (25:23):
You're going to need glasses afterwards.
Speaker 1 (25:25):
Or is that a situation where you would actually say,
let's do the DMC first and then afterwards, let's come
back and we'll treat the astigmatism with a toric h.
Speaker 2 (25:35):
Yeah, pretty much all of the above, and it depends
on a number of situations. So for example, I have
placed I am very conservative as well, Like there's different approaches,
And for example, Frank Price has reported on performing d
mech first letting the cornea settle and then even placing
multifocal lenses afterwards as a secondary procedure in cataract surgery.
(25:58):
So that is an approach. It's maybe not as realistic
in Canada when we're so limited sometimes with surgical time
and so it may not be a feasible option, but
that is an option that has been described in the literature.
In my case, I have used toric lenses and I
am comfortable offering them. Once again, it will depend on
(26:18):
the type of patient that you have. If you have
early early biometry and you have seen the patient progress,
those were the cases where I used touric and I
based it on the original biometry. I'm more conservative in
terms of offering other types of surgeries or other types
of lenses. Sorry, but conceivably one could put some mild
(26:41):
extended range of vision or even an extended range of
vision lens the problem is the predictability of the result,
and you don't know if they're going to need rebubbling
or other factors. And at this point you're kind of
just wanting to replace the cornea to give them better visions.
So to answer that part of the question, yes, I
have placestoric lenses, not in every situation, but in sort
(27:05):
of well selected cases. I would say that's one thing
I have not found. So I tend to use bi
manual irrigation aspirations, so I will really clean up the
visco elastic. I will then close the pupil and then
proceed with the d NEC. And I have not found
that these lenses have changed or shifted. Again, I don't
have a huge series of these, but I think in concept, yes,
(27:28):
it is possible to do it that way. One important
thing though, is you may sometimes see some level of
astigmatism something that also may mimic some inferior s deepening,
and you may be wondering, is this astigmatism irregular astigmatism?
Is this keratocunus? So a couple of scenarios there. One
(27:49):
is there are some studies that have reported about a
nine to ten percent coexistence of fuchx dystrophe and keratocunus.
So you may very well be dealing with a patient
with caratoconus, and you know you're just kind of discovering that.
But the other thing is that there might be irregularity
because of the corneal edema. And it's also well reported
(28:13):
that once you do the DMC, the cornea will settle,
and maybe that as stigmatism that you were seeing ahead
of time is not there anymore because the cornea now
has det jest and it's more homogeneous. So I don't
think I've answered your question with one single response, but
I think there's It sort of depends on the on
(28:33):
the case.
Speaker 1 (28:34):
No you have, You've given given a lot of considerations
there and options.
Speaker 3 (28:39):
One thing I want to talk about is d SC
versus d mac H.
Speaker 1 (28:43):
I guess it's tough to say with the standard of practices.
I mean, I think both are good procedures. I do
both procedures. I know that there's certain cases where I
just am more confidence I'll get a better result with DSEC,
for example, and the tractimized eyes eyes where there's been
vitreous in the acis where it's just a bit more
of a complicated eye patients where it's tough to position them,
(29:06):
or I just have a feeling that they're not going
to do so well if they need rebubbles in the office,
and I'll even have that conversation with the patient, because
we know that d SC typically needs less rebubbles and
there's less of an attachment issue than d MECH. I
guess my question is from a visual perspective. The reason
we do d MECH is because as opposed to d
(29:28):
SC is because well, one, it's more anatomically correct, so
to speak. You're taking off the decimes and you're putting
decimes back on. Vision is supposed to be more clear.
There's lower rejection levels about five percent versus one percent.
Speaker 3 (29:43):
It's a bit of a loaded question.
Speaker 1 (29:44):
I guess, how much do you think the visual benefit
is of DMECH over d SC.
Speaker 2 (29:49):
Mm hmm, yeah, it's first of all, I mean, in
some of the studies, DMC seems to be slightly better
than d SC, so better than d SC. However, we
also know and there was a publication by Mark Terry
where if you wait long enough, even d SC will
continue to improve. You know, from twenty to thirty twenty
(30:11):
twenty five and by five years, really there's enough thinning
that the vision is very, very good. It's funny because
as we compare the two procedures, I think we also
have our own sets of maybe I'll use no pun intended,
but preconceptions, like preconceived.
Speaker 3 (30:30):
Reference to another podcast.
Speaker 2 (30:32):
Yeah, exactly, preconceived notions. I will say, to be honest
with you, you visited me in my previous life in Manitoba.
My excuse for doing d SC rather than d MECH was,
you know, patients are going to need rebubbles. They live far.
You know, I don't want to be messing up tissue.
So we're talking now about tissue supply, the preparation of
(30:53):
the tissue. I had to prepare my own tissue when
I started doing d MECH, and I was doing all
my preparations, so I had to make sure that the
tissue was well prepped and everything. But eventually, once you
jump into the water and start doing it, you see
that DMCH. For me, it is my favorite procedure. It
still gives me a rush. It's still you know, it's
(31:13):
the excitement of it, the excitement of whether it's going
to open or not, and you have to go in
with the mentality that it is going to open, it
is going to be in the right position. And I
just feel excited every time I do a d MECH.
So as I got more comfortable with d MECH, I said, well,
where is the role or what is the role of
DSEC in my practice? And slowly those desect patients are
(31:36):
the ones you just described, patients with previous bitrechto me
patients with previous surgeries and this and that. And what
I started finding was that in some of these non
routine cases, more complex cases, sometimes they would have detachments.
And I started getting a little bit frustrated. So then
I visited a colleague of mine, Keith Baratz, in a
(31:58):
Mayo clinic, and you know, it's the magic of true
interaction directly with people instead of just virtually as we
had to do with the pandemic. Just visiting someone spending
a day, you pick up so many little pearls. And
he was doing on the desect because it was his
same patient population. He said, look, all these eyes are
(32:20):
more complex, they're more prone to this, They're more prone
to the detachment. So I learned to use the anchoring
sutures so basically going from the limbus through the desect
tissue and out the cornea, leaving sutures that are not
very tight. You don't want the tissue to stretch or
be taught, but they're in good position. You leave the
(32:42):
sutures long. You don't bury those knots. And I often
will put a bandage contact lens. I put two superiorly
and one inferiorly. And so these are patients who have
already had multiple surgeries. So in my mind, it's look,
let's give you one good chance will secure the graph.
(33:02):
We won't worry about the tissue dislocating. Sometimes you do
need to rebubble, but you know the rebubble is going
to be fine because it's in the right spot. And
sometimes they're vitrectormized eyes and so the pressure is low.
These are hypotonic eyes, and as the pressure builds up
and the eye recovers, the tissue is in the right
position and it just sticks to the back of the
(33:26):
host cornea. So that has been kind of the distinction
of my two of my two approaches. So I think
both are great because ultimately the cases where I do DSEC,
they do great with that approach. And the ones who
do where we do d MECH. You know, it depends
on your level of comfort, and I guess as we
(33:46):
do more and more we begin to feel more comfortable
with more challenging cases. But there's a point where it's
a tipping point and then you have to kind of
move towards the desex side, at least in my case.
Speaker 1 (33:57):
So you're saying in those cases where you feel like
dm might be kind of inappropriate or not really necessary
for a couple reasons. One because the eyes of attractimized,
which just makes d MECH a lot more challenging for
those who haven't done it. And probably the visual potential
in some of these eyes also doesn't necessarily warrant that.
Getting that maybe extra aligned with the DMECH versus d
(34:19):
SC doesn't warrant it. But when you are doing the
d SC in those cases, you will add those three
anchoring sutures because you know that it's not just the
DMX that are going to detach there, it's also in
some of the desects. So by giving those three anchoring
sutures putting the bubble in, if it doesn't attach, at
least it's not falling into the ac you can just
put another bubble.
Speaker 2 (34:38):
In exactly because many of these eyes where I'm now
doing d SC, I'm reserving DSECT basically for the more
complex eyes. You know, so first of all, you don't
want them to have to go again through another surgery
or whatever. But also often you put the bubble, you
leave them flat, you go back, raise them up, and
the bubble is gone. You know, like who knows where
it is. These are unicameral eyes, or they have aciol sometimes,
(35:01):
or they've had other surgeries or irregular pupils, and so
you're not relying on that bubble. I'm relying on those
sutures that are there. And it's not you know, I
don't think it's it's being a coward or anything. I
think it's just sort of giving the eye a biggest
chance to recover quickly. And then usually after two weeks
three weeks, I removed those stitches and the corneas do
(35:24):
pretty well.
Speaker 1 (35:24):
That's a really interesting technique. I want to transition briefly
to DSO decimey stripping only. So DSO decime stripping only
was I don't know what you'd call new, but it's
fairly new on the scene relative to d second d
MACH and you basically remove about four millimeters. You do
(35:45):
about a four milimeter decmeta rexis, and you don't actually
do a d MECH or a d SEC and you
just let the peripheral endothelium come in. My initial impression
when I learned about this procedure was that you do
it in cases where there isn't any corneal edema, and
the main issue is that centrally there are gutata, and
the gutata are responsible for the symptoms, and those other
(36:09):
cells will kind of come in and help. Now, the
downside is it takes longer to recover because you're not
putting a transplant in the upside is you don't have
a graft, you don't have to worry about rejection, you
don't have to worry about detachment. I'm curious your general
thoughts on DSO, and I'm also curious if you find
that the criteria for when you would do DSO has broadened,
(36:33):
because I've heard of some people saying, even if there
is a little bit of corneal edema, I'm willing to
do a DSO, Whereas beforehand I thought the paradigm was
more really reserve this procedure for cases where it's the
gutata that are causing symptoms but they haven't yet caused edema.
Speaker 2 (36:50):
So I do have several opinions on DSO so decim
is tripping only or d WEC right decim is without
endothelial CARATOPLASTYDC. First reported or almost almost at the same
time by Greg Maloney who was in Australia now is
in Vancouver, and then Catherine Colby as well. There has
been a lot of studies. The thing that excites me
(37:13):
about DSO is the fact that it's another yet another
paradigm shift right in our understanding of endothelium. It actually
can heal. Right, that was exciting. I mean, all these
years we have thought epithelium heels, yes, dulthelium does not heal,
not so so that was good. There have been good
results with DSO alone, but they were potentiated. And maybe
(37:38):
I'll open a little bit of a parenthesis here in
terms of what innovation means in corneal surgery at this moment.
Because we've talked about the biology of the tissues, understanding
the layers, understanding the healing, understanding that you could put
an air bubble and the tissue heels. We've talked a
(37:58):
little bit about technology, so diagnostics, imaging, perhaps the use
of lasers in some of these techniques as well, but
now we need to bring in the third aspect, which
is pharmacology, and that's where I think those the combination
of those three things is really what's giving us an
exciting time in corneal surgery. I continue with the parentheses
(38:19):
in the sense that you know when I implemented d
mech in brand and Manitoba, we did it for less
than one thousand dollars because all I needed was a
thirty gage needle to dissect the tissue, a lens injector
which we already had, and air which is really inexpensive.
So on the other hand, you have femtosecond laser's eximer laser.
(38:41):
So that's like the whole breadth of technology and techniques
that we have in corneal surgery. So going back to dso, yes,
it can work. If you peel that central formulimeter area,
it can be tricky if you damage that layer, if
you damage the posteriors trauma, it can we eate scarring
in that area. But then how do you potentiate the
(39:03):
recovery with rowukina inhibitors. So another one of these things
where you know, why would we use this, Well, it's
a medication that was originally developed for glaucoma. But it
changes the way the cells work, and it changes the
way that the mitosis occur and the and the microfilaments
(39:24):
inside the cells work, and it allows them to grow
and it starts to have them to grow, and so
some people have used them in some cases of corneal
damage after surgery. But it really has elevated the success
rate of DSO now, so that's the exciting part for me.
The practical part. The practical part is when you look
(39:46):
at some of the results, it's not one hundred percent.
So let's say between seventy and eighty percent of results
of improvement. It may take three, four weeks, five weeks
for those eyes to improve. And at the same time,
you're kind of assuming, well, this is a good technique
if you don't have that much tissue availability. Maybe in
(40:09):
the past that was the case. Fortunately throughout Canada, I
would say things are actually quite good in terms of
the availability of tissue. So for me, from a practical
point of view, I know I have seen patients which
one week later they're seeing twenty thirty, twenty forty, sometimes
twenty twenty five. You know, of course, good cornea very
(40:32):
little time after death, good preservation, all of those things.
But in the ideal patients you can get some impressive
results very quickly. And so in my opinion, first of all,
as I said, I love doing DMC, and second, why
have a patient wait for five weeks? I have done
only one DSO, so maybe I'm not the best one
(40:54):
to comment on this, but those are kind of my
practical aspects. I'd rather give a patient a quicker recovery
with a clean procedure as opposed to well, well I
need to do e K or not and have them
wait and wait and wait for a few weeks.
Speaker 1 (41:09):
Absolutely, and it's not just the visual recovery, it's the
fact that you're making them. I mean, obviously, immediately after
d MECH or desec you're making the patient a lot
worse because it takes time for it to heal.
Speaker 3 (41:19):
You've got a bubble in the eye.
Speaker 1 (41:21):
But you're really making these patients with DSO a fair
bit worse, especially since these are patients who didn't really
have a DIMA beforehand, their main issue was gutatas. So
to then say your vision's gonna be pretty crummy for
about four to five weeks until you start noticing an
improvement is a bit of a it's a decision. But
some people say sure, why not, and some people like
you say, well, we've got DMECH which is getting pretty
(41:43):
good results.
Speaker 3 (41:44):
Let's let's stick with that.
Speaker 2 (41:46):
And there's one other things sale if I may mention,
you mentioned the central gute. It also depends on the population.
You know, not all cornea gutara are the same. So
in my particular practice, I've always seen gute throughout the corner. Yeah,
and so maybe it's the population I have. I just
have found very few patients who would qualify for DSO
(42:07):
as well. So I think that's another kind of bias
in my practice and maybe my perception of things.
Speaker 1 (42:14):
So, doctor Roche, you've talked about a lot of innovation
and paradigm shifts about FUCHS.
Speaker 3 (42:19):
What's on the horizon. A couple things that come to mind.
Speaker 1 (42:23):
You mentioned rokinase inhibitors, and I wonder, outside of the
context of DSO, if we've learned obviously that rokinase inhibitors
can help with endothelial proliferation. I don't know if proliferation
is the right word, so if that has any potential
use on its own. And then this idea of injecting
(42:43):
endothelial cells, which is something I don't know if that's
being practically implemented, but I do know that it's been
studied in labs. The idea of just injecting endothelial cells
into the eye, letting them kind of regenerate the endothelium
without having to do an actual transplant.
Speaker 3 (43:02):
What's on the horizon.
Speaker 2 (43:04):
Yeah, yeah, I but you'd never ask. It's amazing, It's amazing.
I think the only downside to some of these things
is that maybe we will be doing a bit less surgery,
but I'm sure we'll find other techniques to do so,
you're absolutely right. I mean, ro kaine Is is kind
of the first kid in the block to kind of
show promise in terms of a topical treatment that could
(43:27):
modify cells inside THEI, and we still don't have it
available in Canada. One thing for our listeners, I would
say is Kinis gives a very particular honeycomb pattern on
the cornea and epithelial it's a beautiful pattern, but it's
very characteristic. So as we start using it, as it
becomes more available, just watch out for that type of
(43:49):
pattern outside of roke of the ideas. So I've only
heard of anecdotal reports where they're using it to kind
of try to recover corneas after maybe faco with a
lot of edema, but I don't have experience with that.
Now we get into again, Remember I mentioned biology technology
(44:10):
and then pharmacology as well. So one exciting thing that
we're doing and I'm involved in the first part of
this study. It's an observational study, which is basically just
looking at the genetics of Fuchs dystrophy. And so there
is a particular gene which is very highly associated with
(44:32):
Fuchs dystrophy, the tc F four gene. And so just
to summarize what we're doing is we're just looking at
patients with Fuchs. We look at pentecon criteria, so kind
of bringing everything together, and then we're taking blood samples
and determining if the patient has this particular TCF four gene.
(44:55):
Because the company is actually developing drops, simple drop on
the eye that can modify the gene expression at the
level of the endothelium, and the hope is that eventually
we would be able to treat fuge dystrophy just with
a drop as soon as you determine the type of
(45:16):
gene and if it corresponds to the gene that is
matched with this particular medication. So that's one really exciting
thing in terms of preventing the progression of fukes that
we think, you know, it hasn't been done, and that
may be in the horizon in terms of genetic therapy.
Speaker 1 (45:35):
In terms of that particular drop, how would that work.
Could it be working in altering the genetics of the endothelium,
or it would just be able to kind of prevent
the endothelium from continuing to devolve into the gutata form exactly.
Speaker 2 (45:51):
So what happens is that for people who have this
TCF four gene, they tend to form these kind of
hairpins or or kind of almost hair balls within the
nucleus of the cells, which prevents the proper functioning or
proper production of proteins within the cells which allow proper
(46:13):
function and survival of the endothelial cells. So this particular
medication blocks the transcription of this TCF for DNA and
it prevents those alterations to happen within the nucleus, so
the cells continue to function better and continue to sort
(46:33):
of eliminate water from the cornea and do not develop
corneal gutae. Wow, big disclaimers. Are not a geneticist from
a clinician surgeon point of view. Basically, my understanding is
you have an abnormal gene and with these drops you
prevent that abnormal gene from expressing or from behaving in
(46:55):
a bad way inside the cell. So the cells continue
to behave in an or way and prevent the development
of the disease. That's the idea, that's the theory. So
that's genetic therapy at that level. There have been other
therapies injected as well to try to modify the cells
from within. And then, as you mentioned, there's actually different
(47:17):
approaches to cell therapy, and so the first one was
described by Kinoshita a few years ago, both for fuche
dystrophia and also for pseudofacic bullus keratopathy. And the impressive
thing with this is that once again it's that paradigm shift.
You're taking one single cornea and producing and growing cells
out of that single cornea for hundreds of potential injections.
(47:41):
So with one cornia you're treating over one hundred potential patients. Okay,
so those are clinical studies that are happening already, and
you determine the density of the cells, the concentration of cells,
and these are being injected now, injected into the anterior
chamber and oftentimes as an in office procedure, so imagine that.
(48:02):
So there's specific techniques for that as well. Typically in
retina surgery, we want the patients to kind of lie
in a certain position, face down. In d SC DMACH
we ask the patients to lie face up. So after
endothelial cell injection, you ask the patients to position themselves
face down. So the layer that the cornea layers in
(48:25):
that area. Now there's another study which is being developed
by MSL, and so with MSL, what's happening is you
charge the cells in a similar way you grow them,
You kind of make them stronger, but you charge them
with magnetic particles and then you wear a magnetic patch
and also have the patient's life flat and so then
(48:47):
those cells more homogeneously spread throughout the cornea and so
the hope is that then once they're in the right position,
they will take and they will start clearing things up.
So you've got pharmacological therapy, potentially, you've got genetic therapy,
and you've got cell based therapy, and all of them
(49:08):
with pros and cons with cost differences probably as well,
and but all of them really decreasing our need to
take a patient to the operating room, decreasing the use
of resources, decreasing the use of corneal tissue, and hopefully
just sort of improving our overall results and overall quality
(49:28):
of life for our patients.
Speaker 1 (49:30):
All these research innovations might be robbing you of your
favorite procedure, Dmac.
Speaker 2 (49:35):
I know, I'm glad. I'm on my way out in
a few years, so I will just be excited with
all these developments.
Speaker 1 (49:43):
So, actually, Rochie, this has been an awesome conversation. Awesome
isn't a word I use much on this podcast, but
it really has been.
Speaker 3 (49:50):
I've learned so so much from you.
Speaker 1 (49:52):
That's going to influence the way that I, as a
cornea specialist look at my fused patients. And I think
it will also be extremely important and informative to ohomologists
to just want to know more about fuchs and to
want to better understand what they can tell their patients
who have early FUCHS, about what the options are and
about the necessity if they will require a treatment or not,
(50:12):
or even just something simple as you know, I'm not
going to send you to a corneal surgeon yet, but
why don't we get an iol master now, like you
just said, a biometry because that's a pearl you mentioned,
which I think is really smart. Before your cornea is
potentially swollen, let's do that.
Speaker 3 (50:28):
We've talked.
Speaker 1 (50:28):
Just to summarize a few of the things we've talked about.
We talked about the criteria for a triple procedure doing
a t mech or D second a cataract versus a
cataract alone. You talked about some of the traditional criteria
we used in making that decision, but some of the
more modern criteria using SHME flung imaging, which can give
a bit of a five year prognosis to help make
(50:49):
a decision on whether or not that cornea will decompensate
if you don't do the transplant.
Speaker 3 (50:54):
We've talked about IOLs.
Speaker 1 (50:56):
That really interesting thing we just said about doing biometry
right away because the biometry will be more accurate before
a DEMA sets in options for correcting stigmatism. You spoke
about DMAC versus d SC, and how in d SC
you're still using it in more complex cases and you're
also adding those three anchoring sutures you talked about DSO,
(51:16):
And then we just spoke about three really interesting things
on the horizon pharmacological therapies, genetic therapy drops targeting the
TCF four gene, and cell based therapy with cell injection.
So I am so so grateful that you took this
time to go over really a whirlwind of a tour
de force, as they say of Fuchs dystrophe.
Speaker 3 (51:37):
Thank you so much, doctor Rocha.
Speaker 2 (51:39):
No, thank you, Thank you very much, Zelle. It's a
lot of fun to discuss these things, and I just
get even more excited as we see how far we've
come from the original first successful corneal transplant in nineteen
oh five performed by zerm And it was for a
chemical injury and it actually took no seutures, nothing, and
(52:02):
somehow that kind of triggered this whole revolution of being
able to transplant the cornea, no sutures, no sutures. The
patient just had closure of the lids because there were
no sweatures at the time. And the story goes that
an eleven year old boy in a farm got an injury,
penetrating injury, rupturing the sclere and the globe. The globe
(52:23):
had to be in nucleated, and that is the cornia
that Zerm transplanted into this other patient who had had
a chemical burn. Imagine chemical burn to begin with is
a serious injury, but the cornea survived for a couple
of years before the patient died.
Speaker 3 (52:40):
Actually, oh that's incredible. Well.
Speaker 1 (52:43):
Doctor Germa Rocha, a chair of the Department of Ophthalmology
at McGill University, thank you so much for joining me.
Speaker 2 (52:49):
Thank you very much, Dylle a pleasure.
Speaker 1 (52:52):
And thank you everybody for listening to another episode of
blind Spot. Have a great days.
Speaker 2 (53:02):
Listings
Hey everybody, I'm Zaeo Mednik and welcome to another episode
of Blindspot. This episode is sponsored by THEA Pharma Canada.
THEA Pharma Canada is the Canadian subsidiary of THEA, Europe's
leading pioneering and innovative eye health brand. Founded in nineteen
ninety four by Henri Chibre. With five generations of history,
the Chibret family has been dedicated to I care for
(00:30):
more than one hundred and fifty years. Their commitment to
improving lives is born of their pioneering spirit. They continue
to lead the worldwide preservative free movement in eye care.
They've created innovative delivery systems. They've focused on making products
accessible and cost effective for patients. They live this mission
every day because everyone should have the same opportunities to
see the world through healthy eyes. So thank you THEO
(00:53):
Pharmer Canada for supporting blind Spot. Fuchs dystrophy is an
important condition to be aware of before operating on any
patient cataract surgery in particular, or it can cause someone
with otherwise asymptomatic Fuchs to develop debilitating corneal edema. And again,
not everyone with Fuchs dystrophy is destined to develop corneal swelling.
(01:13):
So how do we determine which patients are at increased
risk of corneal decompensation? How do we know which Fuchs
patients warrant combined cataract surgery and endothelial carotoplasty and as
an alternative to corneal transplantation. How do procedures such as
DSO or potentially even endothelial cell injection factor into our
treatment of the condition. I'm joined today by doctor Germo Rocha.
(01:37):
Doctor Germo roach is the chair of the Department of
Ophthalmology and Visual Sciences at McGill University. Native of Mexico,
doctor Roche received his MD from University dad to Annawak
Medical School in Mexico City, after which he completed an
internship at the American British Caldre Hospital. He began his
postgraduate training as a first year resident in ophthalmology in
Mexico City and then came to mcguil for a research
(01:59):
fellowship in ocular immunology in the departments of Ophthalmology and
Microbiology and Immunology, followed by ophthalmology residency training in the
Department of Ophthalmology. After McGill, he studied at the University
of South Florida and Tampa Bay, where he completed a
fellowship in a research scholarship in Cornea and external disease.
For many years he was a professor at the Faculty
of Medicine at the University of Manitoba, and for the
(02:21):
past two decades has been the medical director of the
Ocular Microsurgery and Laser Center in Brandon, Manitoba. He was
president of the Canadian Ophthalmology Society from twenty sixteen to
twenty eighteen and has been an active lecturer and presenter
and has participated in more than one hundred and fifty regional,
national and international leadership conferences over the course of his career.
(02:41):
He is now Chair of the Department of Ophthalmology and
Visual Sciences at McGill University. Doctor Rochell, Welcome to the podcast.
Thank you so much for joining me.
Speaker 2 (02:48):
Thank you so much, Assail. It's great to see you.
I still remember when I met you. You were a
medical student, a very bright medical study gay. But I'd
so great to see how you been branching out in
different expert areas of expertise. I would say, so well, great,
par Thank you.
Speaker 3 (03:07):
It's an absolute pleasure.
Speaker 1 (03:08):
You were one of my first and primary mentors in
ophthalmology and one of the reasons I.
Speaker 3 (03:13):
Wanted to get into cornea. Sir.
Speaker 1 (03:15):
I still remember you doing the first PKP that I
saw way back when and thinking, Wow, that's that's really cool.
And I did one today, so we've come we've come
full circle.
Speaker 2 (03:25):
So circle, that's amazing. That's amazing. No pun intended, right
with a round PKP.
Speaker 1 (03:29):
Yes, no pun intended. I remember the question you asked me.
You said, what's the most important stitch? As you were yeah,
it was a leading question. You were basically giving me
the answer as you were putting in your second stitch
of the PKP. So anyhow, we're talking about fuchs today,
which is a condition where typically you don't need a
PKP because we've become so adept at all of these
(03:50):
new kind of technologies and there's been so much research
advancement over the last fifteen twenty years. Fuchs is a
topic that when we were chatting, you said, I think
that could be an interesting episode, and I certainly think
it's obviously relevant to cornea specialists, but to general optomologists
and optometrists listening to this as well, because there's a
lot of patients who come through the clinic with Fuchs dystrophe,
(04:13):
and if you're not a cornea specialist, and even if
you are in certain cases, it's easy to wonder. Okay,
so how am I supposed to deal with this? How
am I supposed to cancel the patient? What surgery am
I supposed to do? When do they need to see
a cornea specialist to get started? Most people probably know this,
but just give a brief overview, perhaps of what exactly
Fuchs dystrophe is.
Speaker 2 (04:34):
Okay, yeah, I mean it's a topic that has become
almost a passion for me. Fuchs dystrophy affects the inner
layer of the cornia, the innermost layer of the cornea,
which is the endothelium. So as we know, even when
I finished aphalmology, since that time, a lot of things
have changed in cornia, including the fact that we grew up,
(04:55):
I should say, with five layers on the cornia, but
now we've added one layer, the dua layer. And I
remember when I finished my training in nineteen ninety five
and went on to my fellowship. I remember sitting with
one of my mentors and he told me, you know,
nothing has changed in corneal surgery in a long, long time,
(05:16):
and so what has changed in all of these years
is our different perception of fukes. In the beginning, we
would look at a cornea and the sole treatment was
a penetrating carratoplasty and that was it. But as we
learned to understand the different layers of the cornea, and
as we had developments in I think it's three things
(05:36):
that we've seen. Developments in technology, developments in biology in
our knowledge of the biology of tissues, and also developments
in pharmacology. We started splitting that cornea, which is barely
a half a millimeter, into different layers, not just for
the purposes of anatomy, but for the purposes of treatment
(05:58):
in a more customized way. So Fuchs dystrophe has become
very important because for years a condition that affects the
inner layer of the cornea, only we were actually changing
the whole thing, you know, and that we all knew it.
It doesn't make sense. Fuchs dystrophe is a hereditary condition.
(06:19):
It's an autosomal dominant condition which as the cells begin
to become affected, they produce these X crecenses, which we
call gute and they can be seen clinically and they
can be seen on specular microscopy. So as the cells
start loosing their pumping sites, they're pumping mechanisms, then the
(06:40):
water from the aqueous humor begins to kind of percolate
into the cornea, because as we know, cornea's almost like
a sponge, it's drawing water into it. And so as
the endothelial function declines, then the swelling of the cornea
becomes more and more severe, and we go through several stages,
four stages where you begin to have some symptoms during
(07:04):
the morning, the patient cannot see as well, until maybe
a couple of hours later you begin to see problems
with glare or halo, especially when they're driving at night,
and slowly the cornea becomes more edematous and it's more
persistent throughout the day. Eventually, if it's not treated in
a timely manner, they can develop bully, which rupture and
(07:26):
cause pain. And these ruptured bully and persistent pain and
persistent edema result in corneal scarring. And it was usually
at that time when we saw the condition being more
and more advanced that we would say, well, it's now
time to change the full cornia for you so that
(07:47):
you can see again.
Speaker 1 (07:49):
And the way you even explain how the decision was
made when you would do surgery, obviously back then was
different than it is now because beforehand, you weren't going
to take somebody who maybe had a little bit of
edema or just some glare from the gutata and say
let's give you a PKP, which is a huge procedure,
whereas now if somebody is a little bit less symptomatic,
(08:10):
still symptomatic enough, that's a discussion and we'll talk about
some of the criteria. You might be a little quicker
to say, hey, maybe we should treat that. In my mind,
there's kind of two buckets of symptoms. One is gutata
related symptoms where some patients might get glare or they
might just find something's off about the quality of their vision.
(08:30):
And then there are the symptoms that are related to
the development of edema.
Speaker 3 (08:35):
Is that a fair way to look at it.
Speaker 2 (08:37):
I think that's a great way to separate the two
categories of symptoms, and it is also a great way
to kind of discuss the changes in assumptions that we
used to make, and a paradigm shift in terms of
how we treat the symptoms. So, for example, in terms
of assumptions, we used to say, well, the patient has
(08:59):
Fuchs district. Now the cornea is thick, so what level
is it thick enough that we should do a combined
or a triple procedure? And so some people use the
magic number of six hundred and forty microns for example,
and six hundred and twenty five maybe it's a little
bit doubtful. We'll see. Another assumption that we always made
is that if we did a triple procedure, well, magically somehow,
(09:22):
we always calculated those lenses with forty three point five
diopters of k readings or something similar, of course, assuming
that that was going to be our end result. And
so those were two assumptions that were made in the past,
and so you're absolutely right. We used to wait until
the cornea was significantly symptomatic or the patient was significantly
(09:44):
symptomatic to start acting on that. So now the paradigm shift.
So a lot of the things that I'm doing now
I never thought I would be doing in my practice. So,
for example, one thing I don't look at necessarily is
corneli sickness, because we now know that the range of
normal corneal thickness can be from between four hundred and
(10:07):
eighty microns to six hundred and twenty microns two standard deviations,
and so we don't know when that cornea started. Did
it start at four seventy, did it start at five
twenty five? And so what is the increase? The second
thing is we see a lot of patients with refractive surgery,
So how do we know that those cornias that we're
now seeing maybe as normal are not really thin corneas
(10:31):
from previous laser refractive surgery and now they're thick. Another
thing I don't do anymore is to build my medical
decision or my surgical decision, is to look at endothelial
cell counts. So speculator microscopy really is kind of passe
in the sense of deciding what type of procedure I'm
(10:51):
going to be doing. So then what do we do now?
And you're exactly on point. I've had patients who have
twenty thirty vision, twenty twenty five vision, but with central
clumps of corneal gute and they just cannot function especially
if they're driving at night, they're driving and they have
young kids. I remember operating on a young patient who
(11:13):
had to drive their kids to hockey and she just
could not function, and so we went ahead and did
surgery on something that many years ago would have been inconceivable.
You know, a vision of twenty thirty for that. And
the other aspect is the symptoms. So if somebody has
a lot of problems with symptoms and they cannot function
regardless of their vision, and if they have cornea, gutata
(11:36):
and fuchs, then it's a good time to discuss surgery
for them.
Speaker 1 (11:41):
A few comments, they are on some rearly excellent points.
So for bochymetry, of course we don't know what the
baseline is, right, so five point forty is kind of
thought to be the average corneal thickness, so six forty
was thought to be.
Speaker 3 (11:54):
If it's above six forty.
Speaker 1 (11:56):
Then that's one of the reasons why you would do
a triple procedure. For those not familiar with that term,
that means doing cataract surgery and a dsect or a
DMC at the same time.
Speaker 3 (12:05):
Yeah. For me, for example, po chemmetry is more useful.
Speaker 1 (12:08):
I got a consult the other day where it wasn't
necessarily about Fuchs, but it was is there an issue
with this one eye? Is it swollen? And it didn't
look swollen, and it was almost asymmetry between the two eyes.
That's where I sometimes find it to be most useful.
Or if there's symptoms in one eye but not symptoms
in the other eye, then maybe that the chemmetry will
give me some more value. Why have you said that
(12:30):
spec microscopy is a little bit passe? Is that because
we tend to look more now at the symptoms that
they're presenting with and the severity of those symptoms. So
if you know it's Fuchs, and you know that they're
bothered by it, then it doesn't really matter what the
specula microscopy shows you in terms of cell density.
Speaker 2 (12:51):
Yes, in park Yes. The other part is that because
the cornnia gutata is pushing the endothelial cells away, you
really cannot measure adequately the concentration or the density of
cells in the endothelium. And the other thing is that, Okay,
if we're talking about imaging, should we be looking at
(13:13):
other aspects that are more sort of clinically relevant In
our planning and our decision making during Fuchs dystrophee assessment.
And so one of the biggest advances I think for
my practice and one that has really proven to be
a significant contribution are the studies on using shine flug imaging.
(13:34):
And the original reports specifically are for Pentacam on shineflug imaging.
We're developed at the Mayo Clinic by Sanjay Patel. So
what they did was assess shine flug and as you know,
just maybe for our listeners, So shineflug imaging is a
very very high quality, a high definition photography which takes
(13:55):
twenty five or fifty rings of images through throughout the cornea,
providing us information on anterior corneal curvature, anterior elevation, posterior curvature,
posterior elevation, as well as cornial thickness and also now densitometry.
And so the original publications on shine flug imaging for
(14:19):
a Fuge dystrophe looked at if you have certain criteria
over sixty months, over five years, what are the risk
factors for those cornias decompensating enough that you would need
a corneal transplant. And so the three criteria are very simple,
very straightforward, and I actually like I always get a
(14:40):
pentacon on all my paract consultations and obviously FUS patients
as well, and so we look at and review these
with the residents. And so the first one is a
displacement of the thinnest point. And so one could assume
that normally the thinnest point is in the center, and
as you begin to develop a d that thinnest point
(15:01):
is displaced somewhere. It could be nasally temporarily. Second thing is,
as you look at the rings of pachymetry on the cornea,
they're usually concentric, you know, they're very nice and round
and concentric. But as Fuchs develops these rings these isopacks
become not round and concentric, but irregular and distorted. So
(15:23):
second criteria and the third criteria is that as you
begin to get swelling on the cornea, if you think
of caratoconus, you see posterior elevation pushing forward. Well, it's
the opposite in Fuchs because you see posterior depression on
shine flug imaging. And so the three criterias to summarize
(15:44):
are displacement of the thinnest point of the cornea second
irregularity of the isopacks and third is a posterior depression.
And if you have zero criteria then you really have
almost zero risk of decompensating at five years. If you
have one criteria, maybe about twenty percent chance of decompensating.
(16:08):
And if you have two or three then the rates
go pretty high, up to about seventy five percent risk
of decompensating. And so for me, now, yes, I've made
the diagnosis. Yes the patient has symptoms they want to
see better. Now let's look at the shine flug imaging.
If they have two criteria or three criteria, there's no
(16:29):
question I will offer combined d MACH triple procedure, and
if not, I will do cataract surgery alone. And I'll
just be extra careful with protecting the endothelium using a
soft shell technique for example, making sure I'm working in
the bag. And these patients usually do very well.
Speaker 3 (16:48):
That really is quite a paradigm shift.
Speaker 1 (16:51):
And I remember in residency what I had learned was
like we talked about cases in which we would say,
you know what, you shouldn't just get the cataract taken it.
You should get the DMAC or d SC as well,
Like we said greater than six hundred microunds pochemetry. The
other one was mourning blurriness or symptoms. And then if
you see clinical edemo on exam, Now, if they've got
(17:12):
significant morning blurriness or they've got clinical edema on exam,
are you going to be as reliant on the pentacam
or shineslung imaging or are you more so just going
to say at that point kind of regardless what that
shine flug imaging shows, and I'm guessing it probably would
show something. Those symptoms of morning blurriness and the fact
that you have clinical edema, those are quite predictive that
(17:33):
you really do need some sort of endothelia creatoplasty regardless
of what the shine slung imaging is showing.
Speaker 2 (17:40):
Yeah, that's that's a great that's a great point, Zal
because ultimately what we are is treating our patients. Right, Ultimately,
we're not treating an image, We're not treating one single thing.
And I think there's there's usually in what we do
as surgeons and as physicians is we have the science
of everything. We try to be as signific and evidence
(18:01):
based on what we do. But then there's also the
art portion, the sitting down with the patient and asking
them their comfort level, how are they functioning throughout the day,
and if those symptoms and the poor function they have
to enjoy their daily activities kind of corresponds to what
you're seeing in terms of the Fuchs disease in their
particular eye. Definitely, I would go ahead and just do
(18:24):
the and do the endothelial caratoplasty at that point.
Speaker 3 (18:28):
It's really really useful what you're saying.
Speaker 1 (18:30):
And that's not something I've done looking at the shine
plunk imaging, but I'm going to do that more frequently
because there are a lot of cases where I am
kind of fifty to fifty and I can't really tell
is that symptom a cataract symptom?
Speaker 3 (18:41):
Is that?
Speaker 1 (18:41):
Is that a morning blurriness type symptom? Is it kutata
or is it just the cataract. They don't really have
any edema that I'm seeing on exam, and it's tough,
and I kind of say to the patient, I don't
really know.
Speaker 3 (18:51):
I said, it's up to you.
Speaker 1 (18:52):
Sometimes we can try doing the cataract surgery and then
there's a chance to Corney is going to decompensate, or
we could do them both at once, and I think
that's reasonable. But what you're saying is we have some
better metrics now that can actually tell the patient. Hey,
wait a second, you know what, Right now, things look
pretty fine. Maybe I'm fifty to fifty based on clinical
(19:13):
exam and traditional criteria, but let's look at your pentacam
here or your shine flung imaging, whatever you're using, and
actually you are at higher risk. You probably should get
it because your risk of converting in five years is
quite high, which which brings me to my other question.
There is a proportion of patients here correct that will
not necessarily progress. I think some people when they hear
(19:36):
they have Fuchs, they kind of freak out or they're
told by somebody, you're definitely going to need a corneal transplant.
But there is certainly a contingent of patients who might
too fine with cataracts surgery alone, depending on their life expectancy,
and not need that corneal procedure.
Speaker 2 (19:50):
Absolutely, absolutely right, And that's why you know, it depends
on the degree of cataract. If the cataract is more
advanced and they have Fuchs and they have two criteria,
I would be more prone to offering a combined procedure
that they than if they have two criteria and a
milder cataract. You know, And sometimes it's just you've seen
(20:11):
it right, zeal. When you're starting to decimate strip and
you peel you can see the irregularity of the gute,
and as you peel it off, the vision for you
as a surgeon becomes clearer into the anterior chamber, so
you can understand that, oh my gosh, like this this patient,
even though they were seeing twenty twenty five in my room,
(20:32):
they're probably having an awful time functioning in real life.
So there's a lot of art in that in our
decision making.
Speaker 1 (20:40):
One thing you said earlier was that you used to
back in the day, I guess, for lack of a
better term, you used to assume a forty three point
five diopter cornea. Now, when the cornea starts swelling, obviously
the biometry results are going to not be super accurate.
So is there a benefit in certain situations. It's weird
(21:05):
because with cataract surgery, I usually say let's.
Speaker 3 (21:07):
Wait until you're more symptomatic.
Speaker 1 (21:08):
That's my tendency, which is kind of what we're taught, right,
But with Fuchs, if you're going to be doing a
combined d MECH in cataract surgery, is there an advantage
to saying, you know what, let's do it a little
bit sooner before your biometry is off and we're potentially
putting a lens in that doesn't match your eye.
Speaker 2 (21:26):
Well, As you bring up the topic, I think of
what I always say to the general ophthalmologists when seeing
patients with Fuchs, my recommendation in these patients. So I
have several recommendations on these patients, especially if they're not
going to go for a combined procedure. The first thing is,
as soon as you see someone with Fuchs, get a topography,
(21:49):
preferably a shine flow image in and also get a
biometry at your baseline biometry. I have planned years later
even touric lenses in some of these paties based on
the original biometry before the cornea became more edematous, and
the results can be very very good. So you are right,
(22:09):
we are not going to rely perhaps on the more
advanced if that's all we have, that's all we have.
Once they get more edema, you do a biometry. Yeah
it may be good, maybe not so good. But I
try to get and to try to instill the message
that we should get biometry as soon as you make
the diagnosis of fuchs and then keep it there and
(22:31):
see how it changes through the years, as long as
the as well as the shine flow. Second recommendation is
if you think that well there's fuchs, they might decompensate.
Aside from your protection of the endothelium, some people use
BSS plus, some use the soft shell technique. Target your
lens to a result of around minus zero point seventy
(22:53):
five diopters, because after endothelial caratoplasty there can be a shift,
a hyperopic shift, and it's usually of around point seventy
five to one diopter, So compensating for that is also
a good IDEA third recommendation I have is make a
smaller capsule of rexis because by the time, let's say,
(23:13):
if the patient is referred onwards to a cornea surgeon
and we're going to do endothelial keratoplasty, we're going to
be messing with the lens and putting error on this
and manipulating and tapping the eye. We don't want a
lens that's kind of smaller than the opening of the
rexes and sort of the lens coming forward, because that
may cause other problems. And the final fourth recommendation I
(23:36):
have is if the patient comes back they had a
successful cataract surgery, they were doing okay, but now the
vision is going down all right? Is it the fuchs
or is it a posterior capsular opacity. And my suggestion
is don't do a Yag capsulotomy until assessed by a
corneal surgeon, because I would be more prone to doing
(24:00):
a d MECH for example, or a d SC and
these eyes rather than proceeding with a capsule ootomy and
then having the vitrios migrate forward as we're doing our
maneuvers during surgery.
Speaker 1 (24:12):
Those are all really really practical pieces of advice, many
of which I did not know. I'm guessing that means
at least other non cornial specialists, I probably didn't know those.
I don't want to speak for other corneal specialists. One
thing I want to ask you about is a stigmatism.
I've had a couple of cases recently where I've had
a patient with a moderate amount of a stigmatism enough
(24:32):
where it's not just one diopter where I would say,
you know, I really do think you'll get a much
better result with a toric lens. But I'm recommending that
we do a combined FACO d MECH or a FACO
d SC, But you can't really do that with a
touric lens. You can't, or for me, at least, I
find it's pretty tough to put a toric lens in
an eye at the same time I'm doing a d
(24:53):
MECH because as you're, like you just said, maneuvering the
anterior chamber.
Speaker 3 (24:58):
Things are kind of going up and down.
Speaker 1 (25:00):
The toric lenses probably going to shift, and you might
not get it positioned in the axis that's intended. What's
your approach for these patients? Do you ever put a
toric lens in? Maybe maybe I should be putting toric
lenses in during a triple procedure and you're able to
position it properly, would you just tell the patient listen,
(25:21):
unfortunately your eye is not a normal eye.
Speaker 3 (25:23):
You're going to need glasses afterwards.
Speaker 1 (25:25):
Or is that a situation where you would actually say,
let's do the DMC first and then afterwards, let's come
back and we'll treat the astigmatism with a toric h.
Speaker 2 (25:35):
Yeah, pretty much all of the above, and it depends
on a number of situations. So for example, I have
placed I am very conservative as well, Like there's different approaches,
And for example, Frank Price has reported on performing d
mech first letting the cornea settle and then even placing
multifocal lenses afterwards as a secondary procedure in cataract surgery.
(25:58):
So that is an approach. It's maybe not as realistic
in Canada when we're so limited sometimes with surgical time
and so it may not be a feasible option, but
that is an option that has been described in the literature.
In my case, I have used toric lenses and I
am comfortable offering them. Once again, it will depend on
(26:18):
the type of patient that you have. If you have
early early biometry and you have seen the patient progress,
those were the cases where I used touric and I
based it on the original biometry. I'm more conservative in
terms of offering other types of surgeries or other types
of lenses. Sorry, but conceivably one could put some mild
(26:41):
extended range of vision or even an extended range of
vision lens the problem is the predictability of the result,
and you don't know if they're going to need rebubbling
or other factors. And at this point you're kind of
just wanting to replace the cornea to give them better visions.
So to answer that part of the question, yes, I
have placestoric lenses, not in every situation, but in sort
(27:05):
of well selected cases. I would say that's one thing
I have not found. So I tend to use bi
manual irrigation aspirations, so I will really clean up the
visco elastic. I will then close the pupil and then
proceed with the d NEC. And I have not found
that these lenses have changed or shifted. Again, I don't
have a huge series of these, but I think in concept, yes,
(27:28):
it is possible to do it that way. One important
thing though, is you may sometimes see some level of
astigmatism something that also may mimic some inferior s deepening,
and you may be wondering, is this astigmatism irregular astigmatism?
Is this keratocunus? So a couple of scenarios there. One
(27:49):
is there are some studies that have reported about a
nine to ten percent coexistence of fuchx dystrophe and keratocunus.
So you may very well be dealing with a patient
with caratoconus, and you know you're just kind of discovering that.
But the other thing is that there might be irregularity
because of the corneal edema. And it's also well reported
(28:13):
that once you do the DMC, the cornea will settle,
and maybe that as stigmatism that you were seeing ahead
of time is not there anymore because the cornea now
has det jest and it's more homogeneous. So I don't
think I've answered your question with one single response, but
I think there's It sort of depends on the on
(28:33):
the case.
Speaker 1 (28:34):
No you have, You've given given a lot of considerations
there and options.
Speaker 3 (28:39):
One thing I want to talk about is d SC
versus d mac H.
Speaker 1 (28:43):
I guess it's tough to say with the standard of practices.
I mean, I think both are good procedures. I do
both procedures. I know that there's certain cases where I
just am more confidence I'll get a better result with DSEC,
for example, and the tractimized eyes eyes where there's been
vitreous in the acis where it's just a bit more
of a complicated eye patients where it's tough to position them,
(29:06):
or I just have a feeling that they're not going
to do so well if they need rebubbles in the office,
and I'll even have that conversation with the patient, because
we know that d SC typically needs less rebubbles and
there's less of an attachment issue than d MECH. I
guess my question is from a visual perspective. The reason
we do d MECH is because as opposed to d
(29:28):
SC is because well, one, it's more anatomically correct, so
to speak. You're taking off the decimes and you're putting
decimes back on. Vision is supposed to be more clear.
There's lower rejection levels about five percent versus one percent.
Speaker 3 (29:43):
It's a bit of a loaded question.
Speaker 1 (29:44):
I guess, how much do you think the visual benefit
is of DMECH over d SC.
Speaker 2 (29:49):
Mm hmm, yeah, it's first of all, I mean, in
some of the studies, DMC seems to be slightly better
than d SC, so better than d SC. However, we
also know and there was a publication by Mark Terry
where if you wait long enough, even d SC will
continue to improve. You know, from twenty to thirty twenty
(30:11):
twenty five and by five years, really there's enough thinning
that the vision is very, very good. It's funny because
as we compare the two procedures, I think we also
have our own sets of maybe I'll use no pun intended,
but preconceptions, like preconceived.
Speaker 3 (30:30):
Reference to another podcast.
Speaker 2 (30:32):
Yeah, exactly, preconceived notions. I will say, to be honest
with you, you visited me in my previous life in Manitoba.
My excuse for doing d SC rather than d MECH was,
you know, patients are going to need rebubbles. They live far.
You know, I don't want to be messing up tissue.
So we're talking now about tissue supply, the preparation of
(30:53):
the tissue. I had to prepare my own tissue when
I started doing d MECH, and I was doing all
my preparations, so I had to make sure that the
tissue was well prepped and everything. But eventually, once you
jump into the water and start doing it, you see
that DMCH. For me, it is my favorite procedure. It
still gives me a rush. It's still you know, it's
(31:13):
the excitement of it, the excitement of whether it's going
to open or not, and you have to go in
with the mentality that it is going to open, it
is going to be in the right position. And I
just feel excited every time I do a d MECH.
So as I got more comfortable with d MECH, I said, well,
where is the role or what is the role of
DSEC in my practice? And slowly those desect patients are
(31:36):
the ones you just described, patients with previous bitrechto me
patients with previous surgeries and this and that. And what
I started finding was that in some of these non
routine cases, more complex cases, sometimes they would have detachments.
And I started getting a little bit frustrated. So then
I visited a colleague of mine, Keith Baratz, in a
(31:58):
Mayo clinic, and you know, it's the magic of true
interaction directly with people instead of just virtually as we
had to do with the pandemic. Just visiting someone spending
a day, you pick up so many little pearls. And
he was doing on the desect because it was his
same patient population. He said, look, all these eyes are
(32:20):
more complex, they're more prone to this, They're more prone
to the detachment. So I learned to use the anchoring
sutures so basically going from the limbus through the desect
tissue and out the cornea, leaving sutures that are not
very tight. You don't want the tissue to stretch or
be taught, but they're in good position. You leave the
(32:42):
sutures long. You don't bury those knots. And I often
will put a bandage contact lens. I put two superiorly
and one inferiorly. And so these are patients who have
already had multiple surgeries. So in my mind, it's look,
let's give you one good chance will secure the graph.
(33:02):
We won't worry about the tissue dislocating. Sometimes you do
need to rebubble, but you know the rebubble is going
to be fine because it's in the right spot. And
sometimes they're vitrectormized eyes and so the pressure is low.
These are hypotonic eyes, and as the pressure builds up
and the eye recovers, the tissue is in the right
position and it just sticks to the back of the
(33:26):
host cornea. So that has been kind of the distinction
of my two of my two approaches. So I think
both are great because ultimately the cases where I do DSEC,
they do great with that approach. And the ones who
do where we do d MECH. You know, it depends
on your level of comfort, and I guess as we
(33:46):
do more and more we begin to feel more comfortable
with more challenging cases. But there's a point where it's
a tipping point and then you have to kind of
move towards the desex side, at least in my case.
Speaker 1 (33:57):
So you're saying in those cases where you feel like
dm might be kind of inappropriate or not really necessary
for a couple reasons. One because the eyes of attractimized,
which just makes d MECH a lot more challenging for
those who haven't done it. And probably the visual potential
in some of these eyes also doesn't necessarily warrant that.
Getting that maybe extra aligned with the DMECH versus d
(34:19):
SC doesn't warrant it. But when you are doing the
d SC in those cases, you will add those three
anchoring sutures because you know that it's not just the
DMX that are going to detach there, it's also in
some of the desects. So by giving those three anchoring
sutures putting the bubble in, if it doesn't attach, at
least it's not falling into the ac you can just
put another bubble.
Speaker 2 (34:38):
In exactly because many of these eyes where I'm now
doing d SC, I'm reserving DSECT basically for the more
complex eyes. You know, so first of all, you don't
want them to have to go again through another surgery
or whatever. But also often you put the bubble, you
leave them flat, you go back, raise them up, and
the bubble is gone. You know, like who knows where
it is. These are unicameral eyes, or they have aciol sometimes,
(35:01):
or they've had other surgeries or irregular pupils, and so
you're not relying on that bubble. I'm relying on those
sutures that are there. And it's not you know, I
don't think it's it's being a coward or anything. I
think it's just sort of giving the eye a biggest
chance to recover quickly. And then usually after two weeks
three weeks, I removed those stitches and the corneas do
(35:24):
pretty well.
Speaker 1 (35:24):
That's a really interesting technique. I want to transition briefly
to DSO decimey stripping only. So DSO decime stripping only
was I don't know what you'd call new, but it's
fairly new on the scene relative to d second d
MACH and you basically remove about four millimeters. You do
(35:45):
about a four milimeter decmeta rexis, and you don't actually
do a d MECH or a d SEC and you
just let the peripheral endothelium come in. My initial impression
when I learned about this procedure was that you do
it in cases where there isn't any corneal edema, and
the main issue is that centrally there are gutata, and
the gutata are responsible for the symptoms, and those other
(36:09):
cells will kind of come in and help. Now, the
downside is it takes longer to recover because you're not
putting a transplant in the upside is you don't have
a graft, you don't have to worry about rejection, you
don't have to worry about detachment. I'm curious your general
thoughts on DSO, and I'm also curious if you find
that the criteria for when you would do DSO has broadened,
(36:33):
because I've heard of some people saying, even if there
is a little bit of corneal edema, I'm willing to
do a DSO, Whereas beforehand I thought the paradigm was
more really reserve this procedure for cases where it's the
gutata that are causing symptoms but they haven't yet caused edema.
Speaker 2 (36:50):
So I do have several opinions on DSO so decim
is tripping only or d WEC right decim is without
endothelial CARATOPLASTYDC. First reported or almost almost at the same
time by Greg Maloney who was in Australia now is
in Vancouver, and then Catherine Colby as well. There has
been a lot of studies. The thing that excites me
(37:13):
about DSO is the fact that it's another yet another
paradigm shift right in our understanding of endothelium. It actually
can heal. Right, that was exciting. I mean, all these
years we have thought epithelium heels, yes, dulthelium does not heal,
not so so that was good. There have been good
results with DSO alone, but they were potentiated. And maybe
(37:38):
I'll open a little bit of a parenthesis here in
terms of what innovation means in corneal surgery at this moment.
Because we've talked about the biology of the tissues, understanding
the layers, understanding the healing, understanding that you could put
an air bubble and the tissue heels. We've talked a
(37:58):
little bit about technology, so diagnostics, imaging, perhaps the use
of lasers in some of these techniques as well, but
now we need to bring in the third aspect, which
is pharmacology, and that's where I think those the combination
of those three things is really what's giving us an
exciting time in corneal surgery. I continue with the parentheses
(38:19):
in the sense that you know when I implemented d
mech in brand and Manitoba, we did it for less
than one thousand dollars because all I needed was a
thirty gage needle to dissect the tissue, a lens injector
which we already had, and air which is really inexpensive.
So on the other hand, you have femtosecond laser's eximer laser.
(38:41):
So that's like the whole breadth of technology and techniques
that we have in corneal surgery. So going back to dso, yes,
it can work. If you peel that central formulimeter area,
it can be tricky if you damage that layer, if
you damage the posteriors trauma, it can we eate scarring
in that area. But then how do you potentiate the
(39:03):
recovery with rowukina inhibitors. So another one of these things
where you know, why would we use this, Well, it's
a medication that was originally developed for glaucoma. But it
changes the way the cells work, and it changes the
way that the mitosis occur and the and the microfilaments
(39:24):
inside the cells work, and it allows them to grow
and it starts to have them to grow, and so
some people have used them in some cases of corneal
damage after surgery. But it really has elevated the success
rate of DSO now, so that's the exciting part for me.
The practical part. The practical part is when you look
(39:46):
at some of the results, it's not one hundred percent.
So let's say between seventy and eighty percent of results
of improvement. It may take three, four weeks, five weeks
for those eyes to improve. And at the same time,
you're kind of assuming, well, this is a good technique
if you don't have that much tissue availability. Maybe in
(40:09):
the past that was the case. Fortunately throughout Canada, I
would say things are actually quite good in terms of
the availability of tissue. So for me, from a practical
point of view, I know I have seen patients which
one week later they're seeing twenty thirty, twenty forty, sometimes
twenty twenty five. You know, of course, good cornea very
(40:32):
little time after death, good preservation, all of those things.
But in the ideal patients you can get some impressive
results very quickly. And so in my opinion, first of all,
as I said, I love doing DMC, and second, why
have a patient wait for five weeks? I have done
only one DSO, so maybe I'm not the best one
(40:54):
to comment on this, but those are kind of my
practical aspects. I'd rather give a patient a quicker recovery
with a clean procedure as opposed to well, well I
need to do e K or not and have them
wait and wait and wait for a few weeks.
Speaker 1 (41:09):
Absolutely, and it's not just the visual recovery, it's the
fact that you're making them. I mean, obviously, immediately after
d MECH or desec you're making the patient a lot
worse because it takes time for it to heal.
Speaker 3 (41:19):
You've got a bubble in the eye.
Speaker 1 (41:21):
But you're really making these patients with DSO a fair
bit worse, especially since these are patients who didn't really
have a DIMA beforehand, their main issue was gutatas. So
to then say your vision's gonna be pretty crummy for
about four to five weeks until you start noticing an
improvement is a bit of a it's a decision. But
some people say sure, why not, and some people like
you say, well, we've got DMECH which is getting pretty
(41:43):
good results.
Speaker 3 (41:44):
Let's let's stick with that.
Speaker 2 (41:46):
And there's one other things sale if I may mention,
you mentioned the central gute. It also depends on the population.
You know, not all cornea gutara are the same. So
in my particular practice, I've always seen gute throughout the corner. Yeah,
and so maybe it's the population I have. I just
have found very few patients who would qualify for DSO
(42:07):
as well. So I think that's another kind of bias
in my practice and maybe my perception of things.
Speaker 1 (42:14):
So, doctor Roche, you've talked about a lot of innovation
and paradigm shifts about FUCHS.
Speaker 3 (42:19):
What's on the horizon. A couple things that come to mind.
Speaker 1 (42:23):
You mentioned rokinase inhibitors, and I wonder, outside of the
context of DSO, if we've learned obviously that rokinase inhibitors
can help with endothelial proliferation. I don't know if proliferation
is the right word, so if that has any potential
use on its own. And then this idea of injecting
(42:43):
endothelial cells, which is something I don't know if that's
being practically implemented, but I do know that it's been
studied in labs. The idea of just injecting endothelial cells
into the eye, letting them kind of regenerate the endothelium
without having to do an actual transplant.
Speaker 3 (43:02):
What's on the horizon.
Speaker 2 (43:04):
Yeah, yeah, I but you'd never ask. It's amazing, It's amazing.
I think the only downside to some of these things
is that maybe we will be doing a bit less surgery,
but I'm sure we'll find other techniques to do so,
you're absolutely right. I mean, ro kaine Is is kind
of the first kid in the block to kind of
show promise in terms of a topical treatment that could
(43:27):
modify cells inside THEI, and we still don't have it
available in Canada. One thing for our listeners, I would
say is Kinis gives a very particular honeycomb pattern on
the cornea and epithelial it's a beautiful pattern, but it's
very characteristic. So as we start using it, as it
becomes more available, just watch out for that type of
(43:49):
pattern outside of roke of the ideas. So I've only
heard of anecdotal reports where they're using it to kind
of try to recover corneas after maybe faco with a
lot of edema, but I don't have experience with that.
Now we get into again, Remember I mentioned biology technology
(44:10):
and then pharmacology as well. So one exciting thing that
we're doing and I'm involved in the first part of
this study. It's an observational study, which is basically just
looking at the genetics of Fuchs dystrophy. And so there
is a particular gene which is very highly associated with
(44:32):
Fuchs dystrophy, the tc F four gene. And so just
to summarize what we're doing is we're just looking at
patients with Fuchs. We look at pentecon criteria, so kind
of bringing everything together, and then we're taking blood samples
and determining if the patient has this particular TCF four gene.
(44:55):
Because the company is actually developing drops, simple drop on
the eye that can modify the gene expression at the
level of the endothelium, and the hope is that eventually
we would be able to treat fuge dystrophy just with
a drop as soon as you determine the type of
(45:16):
gene and if it corresponds to the gene that is
matched with this particular medication. So that's one really exciting
thing in terms of preventing the progression of fukes that
we think, you know, it hasn't been done, and that
may be in the horizon in terms of genetic therapy.
Speaker 1 (45:35):
In terms of that particular drop, how would that work.
Could it be working in altering the genetics of the endothelium,
or it would just be able to kind of prevent
the endothelium from continuing to devolve into the gutata form exactly.
Speaker 2 (45:51):
So what happens is that for people who have this
TCF four gene, they tend to form these kind of
hairpins or or kind of almost hair balls within the
nucleus of the cells, which prevents the proper functioning or
proper production of proteins within the cells which allow proper
(46:13):
function and survival of the endothelial cells. So this particular
medication blocks the transcription of this TCF for DNA and
it prevents those alterations to happen within the nucleus, so
the cells continue to function better and continue to sort
(46:33):
of eliminate water from the cornea and do not develop
corneal gutae. Wow, big disclaimers. Are not a geneticist from
a clinician surgeon point of view. Basically, my understanding is
you have an abnormal gene and with these drops you
prevent that abnormal gene from expressing or from behaving in
(46:55):
a bad way inside the cell. So the cells continue
to behave in an or way and prevent the development
of the disease. That's the idea, that's the theory. So
that's genetic therapy at that level. There have been other
therapies injected as well to try to modify the cells
from within. And then, as you mentioned, there's actually different
(47:17):
approaches to cell therapy, and so the first one was
described by Kinoshita a few years ago, both for fuche
dystrophia and also for pseudofacic bullus keratopathy. And the impressive
thing with this is that once again it's that paradigm shift.
You're taking one single cornea and producing and growing cells
out of that single cornea for hundreds of potential injections.
(47:41):
So with one cornia you're treating over one hundred potential patients. Okay,
so those are clinical studies that are happening already, and
you determine the density of the cells, the concentration of cells,
and these are being injected now, injected into the anterior
chamber and oftentimes as an in office procedure, so imagine that.
(48:02):
So there's specific techniques for that as well. Typically in
retina surgery, we want the patients to kind of lie
in a certain position, face down. In d SC DMACH
we ask the patients to lie face up. So after
endothelial cell injection, you ask the patients to position themselves
face down. So the layer that the cornea layers in
(48:25):
that area. Now there's another study which is being developed
by MSL, and so with MSL, what's happening is you
charge the cells in a similar way you grow them,
You kind of make them stronger, but you charge them
with magnetic particles and then you wear a magnetic patch
and also have the patient's life flat and so then
(48:47):
those cells more homogeneously spread throughout the cornea and so
the hope is that then once they're in the right position,
they will take and they will start clearing things up.
So you've got pharmacological therapy, potentially, you've got genetic therapy,
and you've got cell based therapy, and all of them
(49:08):
with pros and cons with cost differences probably as well,
and but all of them really decreasing our need to
take a patient to the operating room, decreasing the use
of resources, decreasing the use of corneal tissue, and hopefully
just sort of improving our overall results and overall quality
(49:28):
of life for our patients.
Speaker 1 (49:30):
All these research innovations might be robbing you of your
favorite procedure, Dmac.
Speaker 2 (49:35):
I know, I'm glad. I'm on my way out in
a few years, so I will just be excited with
all these developments.
Speaker 1 (49:43):
So, actually, Rochie, this has been an awesome conversation. Awesome
isn't a word I use much on this podcast, but
it really has been.
Speaker 3 (49:50):
I've learned so so much from you.
Speaker 1 (49:52):
That's going to influence the way that I, as a
cornea specialist look at my fused patients. And I think
it will also be extremely important and informative to ohomologists
to just want to know more about fuchs and to
want to better understand what they can tell their patients
who have early FUCHS, about what the options are and
about the necessity if they will require a treatment or not,
(50:12):
or even just something simple as you know, I'm not
going to send you to a corneal surgeon yet, but
why don't we get an iol master now, like you
just said, a biometry because that's a pearl you mentioned,
which I think is really smart. Before your cornea is
potentially swollen, let's do that.
Speaker 3 (50:28):
We've talked.
Speaker 1 (50:28):
Just to summarize a few of the things we've talked about.
We talked about the criteria for a triple procedure doing
a t mech or D second a cataract versus a
cataract alone. You talked about some of the traditional criteria
we used in making that decision, but some of the
more modern criteria using SHME flung imaging, which can give
a bit of a five year prognosis to help make
(50:49):
a decision on whether or not that cornea will decompensate
if you don't do the transplant.
Speaker 3 (50:54):
We've talked about IOLs.
Speaker 1 (50:56):
That really interesting thing we just said about doing biometry
right away because the biometry will be more accurate before
a DEMA sets in options for correcting stigmatism. You spoke
about DMAC versus d SC, and how in d SC
you're still using it in more complex cases and you're
also adding those three anchoring sutures you talked about DSO,
(51:16):
And then we just spoke about three really interesting things
on the horizon pharmacological therapies, genetic therapy drops targeting the
TCF four gene, and cell based therapy with cell injection.
So I am so so grateful that you took this
time to go over really a whirlwind of a tour
de force, as they say of Fuchs dystrophe.
Speaker 3 (51:37):
Thank you so much, doctor Rocha.
Speaker 2 (51:39):
No, thank you, Thank you very much, Zelle. It's a
lot of fun to discuss these things, and I just
get even more excited as we see how far we've
come from the original first successful corneal transplant in nineteen
oh five performed by zerm And it was for a
chemical injury and it actually took no seutures, nothing, and
(52:02):
somehow that kind of triggered this whole revolution of being
able to transplant the cornea, no sutures, no sutures. The
patient just had closure of the lids because there were
no sweatures at the time. And the story goes that
an eleven year old boy in a farm got an injury,
penetrating injury, rupturing the sclere and the globe. The globe
(52:23):
had to be in nucleated, and that is the cornia
that Zerm transplanted into this other patient who had had
a chemical burn. Imagine chemical burn to begin with is
a serious injury, but the cornea survived for a couple
of years before the patient died.
Speaker 3 (52:40):
Actually, oh that's incredible. Well.
Speaker 1 (52:43):
Doctor Germa Rocha, a chair of the Department of Ophthalmology
at McGill University, thank you so much for joining me.
Speaker 2 (52:49):
Thank you very much, Dylle a pleasure.
Speaker 1 (52:52):
And thank you everybody for listening to another episode of
blind Spot. Have a great days.
Speaker 2 (53:02):
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