29. The Pterygium (Dr. Allan Slomovic)

Pterygium surgery is one of the more common procedures performed by ophthalmologists.  Yet despite how common it is, multiple techniques are used by different doctors.  In this episode, Dr. Allan Slomovic joins the podcast to share tips on pterygium removal, indications for excision, and pearls on recurrent pterygia.  

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Episode Transcript

Speaker 1 (00:10):
Hey everybody, I'm Jael Mednick and welcome to another episode
of Blind Spot. Whether you're acorne a specialist or a
general ophomologist, prigium surgery is something that's very commonly performed
by iecare professionals. But as common as trigium surgery is,
there are many different techniques that are used. What are
some of the key aspects when excizing a trigium that
are key in preventing recurrence. What are some of the

(00:31):
important considerations we might not think of when using draft
and how do we address turigium recurrence. To discuss trigiums,
I'm joined today by doctor Alan Slomovic. Doctor Slomovic is
the Vice Chair of Education and Continuing Education Director for
the Department of Ophthalmology and Vision Sciences at the University
of Toronto. He's also the clinical director of the Cornea
External Disease Service at the Toronto Western Hospital University Health Network.

(00:54):
He's the past President of the Canadian Ophthalmologic Society and
previous Chair of the Canadian Cornea External Disease Society At
the Canadian Ophthalmological Society. He's a Professor of Ophalmology at
the University of Toronto and the Marta and Owen Boris
and Dowd Chair and Corny and stem cell Research at
the University Health Network. He completed his residency training at
New York University School of Medicine in Manhattan, followed by

(01:16):
two separate fellowship programs at the Baskin palmer I Institute
in Miami, Florida. In twenty fourteen, he was nominated by
Toronto Life as one of Toronto's Best Doctors. He's been
nominated as one of Toronto's Top doctors by City Posts
for the past three years consecutively. All right, doctor Alan Solanovic,
welcome to the podcast. Thank you so much for joining me.

Speaker 2 (01:35):
My pleasure to be here. Thank you Zeal for inviting me.

Speaker 1 (01:38):
This is a very apt topic because you were my
fellowship director and my mentor in fellowship when I did
at the University of Toronto, and I recall doing some
triigiums under you, and I recall the first one we
did actually where you showed me some of your techniques
which I use today because they're really great techniques and
you are really an expert in this area and the
perfect person to have about this top I want to

(02:01):
start off before we talk about the techniques of trigium surgery,
just reviewing some of the indications for excision, because I
think for a lot of people it's tempting to say, oh,
you got its origium, it needs to be removed. But
in reality there are criteria which are important to follow,
and I'll say a few of them, and then I'm
curious to get your thoughts if I'm missing any. Obviously,

(02:22):
if it's large or if there's evidence of growth, typically
it's greater than three millimeters, and it's probably significant if
it's causing irritation or kind of recurrent redness or symptoms
for the patient. And then this element of a stigmatism reduction,
whether it's in general because it's causing a lot of astigmatism,
or whether it's preoperative before a cataract surgery to optimize

(02:42):
the result. Are those the main indications in your mind
when you decide to take a trigium off.

Speaker 2 (02:48):
I think you hit on the high points. Sell. I
like to look at this as as I do any
other disease pathology. There are absolute and they're relative indications.
I think in terms of apsolt indications, you mentioned most
of them. You know, if it's either involving the visual
axis or threatening the visual axis. That's one of them.

(03:09):
Stigmatism is another one, and we can talk a little
bit more about that afterwards. I've seen indications is rare,
usually with recurrent regimes where they've actually involved the muscle
and resulted in diplopia. And I think another fourth absolute
indication would be, you know, if you're suspecting is this
an oss inn or is this a TriGem. I've seen

(03:30):
quite a few cases of oss in that actually could
pass off as a trigium. We know it's the same location,
you know, it's UV exposure, same underlying factors. Relevant indications
is usually you know, redness, irritation. Patients tell me my
eyes are red, but my friends asked me if I've

(03:50):
been drinking, So it's embarrassing to the patient. So that's
a relative indication. Depends on how much it bothers them. Also,
if they want to either wear contactor have refractive surgery,
that's another relative indication. And you mentioned cataracts. I think
you know it depends. You know, if it's an elderly

(04:11):
patient with a small stable trigium that's not causing the symptoms,
not growing, not causing any significant astigmatism. You could leave
that alone. It's unlikely that taking it off is going
to make a big difference. But I've seen trigims smaller
than three millimeters that will end up with, you know,

(04:33):
seven or eight adopters of an irregular with the rule
of stigmatism.

Speaker 1 (04:38):
That's a really important point about a stigmatism reduction. And
I do find in practice that it is a little
bit challenging sometimes to have that conversation. Or there might
be a small trigium and the topography is a bit
affected by the trigium, and I wonder would there be
a better rule for trigium surgery prior to cataract surgery.
But sometimes I have to kind of gauge by the

(04:59):
patient or just say to them, listen, we might make
things a little bit more perfect if we go through
the trigium surgery beforehand, wait a few months, normalize the topography.
Some patients say sure, and some patients say, especially if
they're more elderly, they say, you know, when I'm not
really in the mood for kind of doubling the procedures.

Speaker 2 (05:15):
Right. Sure, it's all patient dependent, but you know, as professionals,
we advise them, you know, and you have to look
at the gestalt. It's not one factor alone. It's age
of the patient. It's how large the trigium. Is it stable,
is it growing? Is it causing a stigmatism. I've got

(05:35):
a topography on every patient that gets referred for trigium,
and I've left some a lot, I've left some. You know,
you pointed out an elderly patient with a stable, small,
non astigmatism causing trigium. Leave it alone, Just take out
the cataract, Just do what they came for. But if
it's larger and you're seeing more stigmatism, I think we

(05:57):
have to inform them that they should have the trigium
out right. And I typically do that and I wait
two months until you know the ocutave surfaces a stable
topography shouldn't be changing at that point, and then I
do my biometry and I plan for surgery.

Speaker 1 (06:18):
Let's focus the rest of the conversation on excision once
you've decided that you want to do it for whatever reason,
like we just talked about, and you did a great
job illustrating those absolute indications and the relative indications for surgery.
One thing that you showed me in fellowship that I
found extremely useful in regards to excision was how you
kind of developed a plane at the edge of the

(06:38):
trigium to help get it to come off in one piece.
It's a bit tougher obviously in these kinds of conversations
when there's no video, But do you want to maybe
explain what your approaches, because that really helped a lot
for me in terms of getting the full trigium off
in a smooth way.

Speaker 2 (06:55):
For sure. You know, like other forms of stem cell surgery,
it's getting that plane that's really important. So what I
like to do is all off fifty seven beaver blade
otherwise known as a hockey hockey stick, and then I
like to sort of break the epithelium just in front
of the leading edge of the trigium, and then with

(07:17):
a scraping like a firm scraping motion, the trigium starts
to lift up. And then once you're in that plane,
keep that plane. So essentially you should be pretty much
in a bloodless field when from the beginning of the
trigium to the limbus. Once you hit the limbus, you're

(07:37):
gonna get blood vessels and it's gonna bleed, but you
should pretty much have a plane that you can follow,
and I like to do that by going a little
bit maybe a millimeter in front of the leading edge
of the trigium and then just sort of using a
fifty seven beaver blade to sort of find define the

(07:59):
edge of the trigium and the plane, and it comes
off quite nicely like that. Now I've also done not
as often. I like to mark where on the conjunct
taiva with a with a marking pen before I start
doing the surgery, because what you're what you're gonna notice
is once you've once you've taken off the trigium with

(08:19):
Tenon's tissue, what you thought was a small content tival
reception actually becomes a large conjunc tival reception. So I
like to do that before I start surgery. And I
encourage people who are starting to do trigion surgery to
mark where you're going to be cutting the consent taiva,
and you want to make a point of avoiding the

(08:40):
chronicle because that'll scar.

Speaker 1 (08:42):
Yet. How you said there that you start one millimeter
anterior to the trigi, and that's what I found really
really helpful for me to get that plane. I think beforehand,
I was starting right at the trigium. But it's easier
to get that plane if you start a millimeter or
so anterior where there's a more normally appearing epithelium, and
then you're able to really scrape it up.

Speaker 2 (09:02):
One hundred percent. And if you start at the area
of the trigium, there's blood vessels there, it's going to bleed,
it's going to obscure your view, so you've got to
start in front of the trigium.

Speaker 1 (09:12):
You mentioned that you mark the trigium, and while I
think there's a couple benefits there, one is exactly what
you said, and that it shows you really that it's
typically a much larger area of excision than you anticipated initially.
Another is it relates to the importance of a tanek
to me removing tenons and sometimes it can be a
little bit fuzzy as to what's tenons, what's conjuinc taiva,

(09:35):
And by doing the marker on the conjunct taiva, it
lets you know what is actually conjuc taiva and the
stuff that isn't marked is tenons. I want to talk
to you about the importance of removing tenons because some
people believe that a trigium is a disease of tenons.
Some people believe it's a stem cell disease. Some people
believe it's a little bit of both. How important in
your technique and in your mind is removing the tenons

(09:58):
underlying the conjunct in the area of the trigium.

Speaker 2 (10:02):
You know, I like to remove it. I think there's
benefit in doing so. I think what you want to
do before you start removing is you want to do
blunt dissection between the the sclera and tenons tissue in
conjunctiva complex. So once you've done the blunt dissection, it's
easy to pull on tenons tissue. And I pull on

(10:23):
it and I cut it with a Wescott scissors and
it comes out quite nicely. I don't think you need
to go after every piece of tenons tissue. I don't
think you're going to get that. But I do remove
tenons tissue in all cases.

Speaker 1 (10:36):
That's useful to hear because sometimes I feel like I
am probably a little bit too aggressive because I do
hear you should take tenons out, and then sometimes in
certain patients you get a lot of bleeding, and I
wonder was it really worth going for that extra tenons
When I've created a lot of bleeding, which you can
obviously control. So that's reassuring, I think probably for me
and other people who are listening to this. It's important

(10:56):
to get tenons out, but maybe you don't have to
chase it too hard.

Speaker 2 (11:00):
And with the bleeding. You know about this, if you're
getting bleeding on episcleural vessels, you know, I like to
try to limit my charcterization as much as possible because
I think that causes post operative inflammation and I think
that can be an impetus towards recurrence of the trigium.

Speaker 1 (11:19):
One thing I've heard conflicting advice on is extra ocular
muscle management, so to speak. That's a weird way of
saying it. I've heard that some people use muscle hooks
to isolate the muscle. I think most people probably don't.
What's your impression on that.

Speaker 2 (11:35):
Well, you know you've got to be you got you
know that the medial muscles, which is probably the most
important in it. Usually it's a medial trigeon is about
five point five millimeters from o limbus. Usually when with
a primary trigium, it's not difficult. You know. I've seen
trigions and I've dealt with trigims that have been excised
five times with recurrence, and there's a lot of scar

(11:57):
tissue and a lot of bleeding, and it's kind of hard.
I find gel phone actually to be very helpful in
these situations to control some of the bleeding. But you
know where you have. Usually in the case of a
recurrent regime, I will use a muscle hook to identify
the medial rectors and then you still get you know,
the muscle is, you can have fibrous tissue on it.

(12:19):
I don't go as far as dicec. I'll try and
dissect off what I feel is safe to dissect off,
but you know, you may want to identify the muscle
just so that you're sure. More so in these recurrent cases.
It's it's the anatomy is not as clear in recurrent rigims.
In a primary I can't remember the last time I

(12:40):
may have used the muscle hook. You really don't need
it because you can see well enough and there's not
all that extra scar tissue, fiber's tissue and bleeding that
obscues the view of what you're doing.

Speaker 1 (12:51):
Yes, the anatomy is a little bit more obvious in
a primary trigime, which is the ones that most of
us are doing. At least you do a lot of
recurrent ones, not not your own recurrences, recurrences from.

Speaker 2 (13:02):
So we all get you know what, the only way
not to get a recurrence is not to do surgery.
You know, our recurrence rate is low. We looked at it.
We thirteen or fourteen years ago in the Ajao we are.
We initially started doing recurrences with mitomycin zo point two
percent for two minutes combined with tissue glue, and our

(13:24):
recurrence rate was three point five percent, which which is
really good. I think we all know that adjuvents like mitomycin,
that's the most common use antifibrotic agent to try to
prevent recurrence. So even even with that, I still had
a small recurrence rate, and we all do. Lately, I've
changed my technique for recurrences. And this is really a

(13:46):
field and evolution. And it happened when I had patient
with kissing trigium and we published this in the Canadian
Journal of Alphamology. Patient had kissing trigiums had trigim surgery
with the content tival autographed and my mycin done by
a very good corneous surgeon with massive recurrence and I
did a simple limboll epithelial transplant or what we call

(14:10):
a SLT procedure, and patient was trigion free three years later.
We subsequently, about four years ago, I believe it was,
we published we did a study on this we looked
which we published in the AJO, using SLEDT for recurrent trigims,
and our results again were very good. We did have

(14:33):
one recurrence and a patient with five previous recurrences, and
we've had recurrences out of the study too. I do
a lot of recurrent trigims, but it is a good technique.
The one recurrence that we had in our study was
a patient who had five previous recurrences and in three
years the trigium the recurrence just crossed the midline much initially,

(14:56):
the trigium went into the visual axis and it was stay.
So although the patient was happy and I was happy,
we still called it a recurrence. So simple imble epithelia
transition does offer you another option to treat recurrence, as
not everybody knows how to do it, but it is
another option.

Speaker 1 (15:16):
And for those who aren't familiar with it, can you
just give a brief explanation of what slat.

Speaker 2 (15:20):
Is sure well SLEDT comes from Verindus Sanguin from hydrobad
India who developed the technique, and what it is basically
is harvesting. I like to try to do ipsy later all,
but sometimes you have to go to the other eye,
and it's harvesting a small area something like four millimeters

(15:41):
wide by two millimeters in length of tissue that carries
stem cells. Then I put that on a gauze well
you know, well hydrated in a petri dish, and I
put it aside to the end of the removal of
the tridium. Then do my trigium surgery. And when I'm

(16:02):
finished doing that, what I usually will use mitomycin for
two minutes, and then I do an amniotic membrane transplant.
I put amnion down using tissue glue, and then I
go to my sample of stem cells that I've taken.
I cut that into about ten pieces, I put it around.

(16:25):
I usually put a double layer around the area where
the trigium was, and I hear it with tissue glue.
Sometimes not all the time, I'll put a like another
layer of amnion just to protect the pieces, and I
cover that with a bandage contact lens.

Speaker 1 (16:43):
Yeah, it's a really elegant procedure. I saw you do
it a lot more.

Speaker 2 (16:46):
To explain without slides and videos.

Speaker 1 (16:49):
I think you articulated that well there, and you do
that a lot for some of the more complex recurrent trigiums.
And it's the procedure that works really well, and people
can look it up online. Obviously there's there's videos for
some of the scurrence is let's say it's an earlier
recurrence in patients and you are doing a regraft mitomycin C.
In those situations, are you more inclined to use amniotic

(17:12):
membrane or do you feel comfortable enough going back to
the superior conjunct TIEL and taking another graft.

Speaker 2 (17:18):
That's an excellent question, you know. I debated that at
the American Academy of Ophthalmology. I did conjunct title graph
but there was no question and it won. But there's
no question that a conjunct title grapht is more effective
in terms of recurrence, right, it has less recurrence than
an amnion. It is cost effective, especially in some of

(17:39):
these countries in Africa where they have a high incidence
because of their UV exposure. They can't afford amnion. If
they're getting it processed, we know the side deffects and
you know the conj it's readily available so and has
a better cosmetic result. So I'm a big fan of
I think it's the gold standard, doing a constent time,

(18:00):
a lot of graph so you can go back. You know,
when I do the initial one, the conch graft, I
try not to take Tinon's tissue. I try to just
get content taiber and you can go back six months
later and re harvest the same area. And what I
like to do before I book it, I will look
at the patient at the slit lamp under topical anesthetic.
I'll take a cotton tipped applicator and I just rubbed

(18:21):
the superior bulber conjin taiva where we're going to take
the content tyble graft. I mean, if it's scarding to
I don't I can't remember ever not being able to
harvest that. But the other option is doing an inferior
conjuc tyble graft, and we published that as well. Technically
it's a little more difficult. I recommend putting in a

(18:44):
like a suture through the corner through the inferior cornea
near the limbus, so you can maneuver the eye up
to get access to the inferior conj and we published
this and we found there was no difference in recurrence
or side effects with an inferior compared to a superior graft.

Speaker 1 (19:04):
That's a really important point. I think about trying with
a cute tip because that can give you that sense
of Okay, is this going to be more challenging even
if I can do it? Is it going to be
more challenging? Is there scar tissue that's formed here? And
maybe in those rare situations, say I'm going to pivot
whether it is going inferiorly or whether it is going
for amnon and a recurrence. What's the thought on avastin.

(19:24):
I know that some people use a vastin for early recurrences,
and the vastin is used for a lot of things.
Obviously the retina specialists to know that, but in the
cornea it's used for sometimes for interstitial carotitis or blood
vessels that are growing. And I wonder for tririgiums what's
the role because in my mind, I think, yeah, it's
going to help with the blood vessels, But a trigium
is more than just blood vessels. It's this fiber vascular complex.

Speaker 2 (19:48):
Yeah. I think the blood vessels are secondary and a trigium.
So we've published on a vastin in reducing corneovascularization and
it does. It's not as effective as MI, which is
the new kid on the block, but it's a lot safer,
you know, That's some of what in terms of a trigium.
You know, I we published on this as well. I

(20:10):
have not found it to be effective in reducing trigiums.
There was one, there was several articles on this. The
majority of the consensus. I think there was one article
that did say it was effective, but I have not
found it to be in my own personal experience, and
I think the majority of the literature and the consensus
is it is not effective in reducing or getting rid

(20:31):
of a trigium.

Speaker 1 (20:33):
Intuitively, that makes sense because, like you said, the blood
vessels are kind of secondary to the trigium. The main issue,
the primary issue is not necessarily the blood vessels. When
do you typically see the recurrence? Obviously there's outliers and
you can see recurrences years later, but for most people
who are following their patients, can they be reassured if
they've seen their patients in three or six months, that

(20:55):
it's likely not going to recur now if I'm not
seeing any early signs of recurrence.

Speaker 2 (21:01):
So again we published this, and there's other authors who
published this as well. Typically it's four and a half
months you're going to see a recurrence of the trigium.
So I see my patients a week, a month, and
four months, and if it's as to recur, then it's
unlikely that it's going to And you know, if you're
doing a conch graph, the stats are so good they
go from like one to three percent recurrence rates. The

(21:24):
important thing is, I think to do a conch graft,
I think it's still the gold standard today.

Speaker 1 (21:30):
When we're doing con graphs. Most of us use glue, naw,
whether it's to seal artists or some sort of fibrine
type glue. When glue is not sufficient and the graph
isn't staying in place as well as you wanted to do,
what's your preferred suiture type. And the reason I ask
that is one because I think it's a practical thing
that people need to know. And the other is I've

(21:50):
seen some debates where some people have really really spoken
about vikral and how inflamed it causes patients to be.
So I've debated because vikral, you're in the sense that
we don't need to worry about removing the stitches afterwards,
but nylon, even though you have to remove it, it might
be less inflammatory in an already uncomfortable procedure.

Speaker 2 (22:10):
Yeah, so, Satish and I published this in the British
Journal of Alphamology years ago where we started using glue
and there were two patients came in I think five
and seven days after. They were both eye rubbers. One
graft was like d hissed, all pushed over on one
side and the other graft was just one of the
corners were significantly rubbed in, so there was bear sclera.

(22:33):
There was a large area BA sclare. Basically what we
did we took them back to the treatment room and
under a bed of tissue glue, we just unraveled the graft.
We did use sutures. You know, I agree with the
with what you were saying about vikral. It is inflammatory.
You know the retina glaucoma people use a lot of

(22:55):
seven zero eight oh vikral. I used ten O vikral.
It's it's very difficult and finicky to work with. You know,
when I was I went once a while ago to
the battercare I Institute, and the way they did it
was tenno nylon, but they left the ends long and
then they take them out after about a week. So

(23:16):
I haven't put sutures in a in a content title
autographed in a long time, but if I had to,
I would. What I did before I started using tissue
glue is teno nylon. Leaving the ends long. If you
if you're cut it short, it's like it'll it'll irritate.
Leaving it long, it'll feel a little bit like a
foreign body, but it's better tolerated. But my first I

(23:39):
wouldn't give up on the glue. I would just try
to fix the problem and reglue it.

Speaker 1 (23:45):
When a lot of patients come in and they're asking
did I do anything wrong? And I even had a
patient today which is the reason I'm asking this, who
said what did I do? I I'm not sure. I'm inside.
A lot of the time I wear sunglasses and I
say no, I mean, a lot of it is just
kind of it is sun exposure, but a lot of
it's just bad luck genetics, and there's really not too
much for you to do. I mean, if a patient

(24:07):
has a trigion and there's not much they can do
about it in hindsight. But are there any recommendations you
suggest to people aside from basic sunware stuff? Is there
any other factors in the eediology that we have more
control over than we may traditionally have thought about.

Speaker 2 (24:23):
You know, I wish we did, and as doctors would
always wish we could tell our patients something. The only
thing I think that you know, we know there's there
could be. Genetics is one factor, but you can't change
your genetics. The other thing is the I tell my patients,
especially after surgery, make sure you're wearing UV blockers when
you're outdoors. I think we know the whole concept of

(24:46):
the trigian belt being twenty degrees north and south of
the equator where there's a higher prevalence of turigiums, so
we know that there's an association. So my recommendation, you know,
I wish I could tell them more. The other thing
is why is it sometimes people will have a trigium
just in one eye both eyes are exposed in a
similar way. But I think the only thing we can

(25:09):
tell them as professionals. Is you know where a UV blocker,
especially on bright sunny days good.

Speaker 1 (25:16):
That validates that I'm not missing anything when I'm telling
that to patients. Do you have any final thoughts about trigimes,
maybe misconceptions or important pearls about trigians that you think
more general optimologists and cornea specialists should be aware of
when when treating them.

Speaker 2 (25:32):
Yeah, of course, you know, not everything that looks like
a trigion is a trigion. But there's a whole category pseudotrigems.
Oh ss n. We've already spoken about. And if you're
questioning that, make sure you can get pathological readings on
the specimen and that you follow that up. You don't
just leave it. Other causes of pseudotrigims artarians more in

(25:54):
Zultzer and the cornea is really thin underneath, So if
you have any question about that, you want to go
see t which will help you look at the cornea,
at the thickness of the cornea. You don't want to
end up with a perforation when you're doing a trigium.
I mean, that's a big problem and it could be avoided.
And if you if you're suspecting that the cornea may
be thin underneath. I've also gotten to oct in cases

(26:17):
where you know, I've had numerous recurrences and I didn't
know if the previous surgeon took out some of the
you know, the stroma. At the same time, especially in
a thickened in a recurrent numerous recurrences, you want to
know how thick the underlying cornia is so that you
don't end up with a prefer.

Speaker 1 (26:37):
Doctor Slomanic, I think this was extremely valuable, going over
the indications of when it's really helpful to take off tigium,
and sometimes it's black and white, sometimes it's gray, and
then a lot of really useful techniques about excision, graft type,
and some techniques for recurrence, whether it's mitomycin c, whether
it sounds like not a vast and ultimately sled which

(26:58):
is a bit of a more complex procedure, but people
people can learn that too. Thank you so much for
joining me and taking the time to join the podcast.

Speaker 2 (27:06):
Ziel was an absolute pleasure, and I look forward to
seeing you at future meetings.

Speaker 1 (27:11):
And thank you everybody for listening to another episode of
blind Spot. Have a great day.