AMC’s Usdan Institute Presents: Diagnosis & Treatment of Cataracts in Pets

My name is Jackie Skidmore and I’m the
Director of the Usdan Institute for Animal Health Education here at AMC.
We’re so pleased to have AMC’s Dr. Alexandra van der Woerdt here with us
tonight. She is board certified by both the
American and European Colleges of Veterinary Ophthalmologists. She came to
AMC in 1994 and currently heads our Ophthalmology Service. She also serves as
a Director of Postgraduate Education at AMC shepherding our interns through
their very confusing and difficult intern year here. She’s received several
honors and awards including the Clendenin J. Ryan Memorial Teaching Award in 2001
and was named Veterinarian of the Year in 2006 by the New York City Veterinary
Medical Association. She received the award for outstanding
service to veterinary medicine from the New York City Veterinary Medical
Association in 2015. We’re very grateful to have her speaking here tonight so
without further ado, please welcome Dr. van der Woerdt. Dr. van der Woerdt: Thank you everybody for coming. It’s always great to see so many people. I see quite a number of faces
that I recognize and then there’s of course new faces, so that- that’s very
good. You can’t hear me? Okay. Well I guess I’ll just have to scream a bit more. Can
you hear me now? It sounds like the Verizon commercial, isn’t it? Can you hear
me now? All right. So tonight we’re gonna talk about
cataracts. And cataracts- a lot of what I’m gonna say is gonna be the same
whether it’s a dog or a cat. I’m gonna- most slides will be about dogs and in
the end I’m gonna say a few specific things about cats. But pretty much
whatever’s on each slide can apply to both dogs and cats. So I’d first like to
introduce my team at the Ophthalmology service. This picture was taken after a
very long surgery day but there’s myself. In the middle is Thomas Hall, my
technician and then on the other side is Pete Pineda. He’s a recent addition to
our team and he’s an assistant. He’s been amazing as well. So anytime you want to
get a hold of us, you’ll probably get either one of the three of us. I also have to
immediately say that I am not the best in taking pictures. I tend to forget. So I
actually honestly contacted one of my colleagues on- who’s on Long Island, Dr.
LaCroix, was much better at remembering to take pictures than I am so some of
the pictures in this presentation are actually from her. So what are we gonna
talk about? Well there’s a number of things we’re gonna talk about. First
we’re gonna talk about the anatomy of the eye- the various structures within
the eye, what are they and what is their function, and then after that we’ll talk
a little bit about a cloudy eye because there’s many reasons for an eye to be
cloudy, not just a cataract. Then we talk about- specifically about
cataracts. For the causes and the stages of cataract formation, the treatment of
cataracts, the aftercare after cataract surgery, success rate, possible
complications of cataract surgery in dogs and cats, and then a few specific
things about cataracts in cats. So we talk about anatomy of the eye and
here’s a very schematic drawing, where if we look at it, we’ve got here that the
eyelids of course are not on this picture, but then the conjunctiva is the
tissue that lines the eye, the cornea is right here. There we have the iris. we
have the lens, the vitreous which is like a gel, and then back here is our retina
and the optic nerve. The eyelids. The eyelids are very important to help
protect the eye and the reason why I put this picture here, because as you can
tell, these eyelids do not do a great job protecting these eyes. And of course, it’s
got absolutely nothing to do with cataracts, but it’s just something that I,
when I was thinking about the eyelids and their function, like yeah, the eyelids
are very important to keep the eye protected. They blink. They- of course
they’re supposed to blink. They spread the tear film. They remove foreign material
that comes into the eye from the environment and they- they help, like I said, they help
protect the eye. The animals do not have eyelashes like people do so sometimes we
talk about something that’s called distichia which is extra eyelashes and
the reason why we say they’re extra, because dogs don’t really have eyelashes
like people do. The hair start a little bit away from the eyelid margin.
The eyelids do have multiple, multiple glands that secrete part of the tear
films, kind of a waxy, fatty substance that is part of the tear film. The
conjunctiva is the tissue that lines the eye. It is normally transparent with a very few blood vessels. If it becomes inflamed and red, we have what a lot of
people would refer to as pinkeye. It’s a very common thing both in dogs, cats,
people, we see it all the time. And that inflammation can be because of very many
different reasons. It could be that it’s just an allergy to something or maybe an
animal could have some- gotten something in the eye and it just
irritated the eye and that’s why it’s red. But it can also sometimes be a sign that
there’s something much more significant going on inside the eye. So redness of
the conjunctiva is something that can be just very harmless but potentially, it
could have disease that could be associated with more significant
diseases as well. This dog does not have normal conjunctiva. It had a lot of extra
fluid buildup under the conjunctiva because of an allergic reaction. The
cornea. The cornea you typically actually don’t see because that’s a completely
transparent structure. That is in front of the eye. And this was actually picture
front of a previous greyhound of mine and as you can tell, the cornea is here
but you don’t really see it because you see the iris here, you see the lens here, this is just third eyelid, and that’s where it’s supposed to be. The cornea is
supposed to be completely transparent. It’s not supposed to
have any blood vessels. Supposed to be completely transparent. It’s a very
delicate structure and that’s one of the reasons why it’s so important to have
good functioning eyelids to help protect the very delicate structure. And of
course, there’s lots of diseases that can affect the transparency of the cornea
and the reason why that’s actually important for a cataract surgery lecture,
or a lecture about cataracts, because kind of jumping ahead, if we’re going to
potentially do surgery, I’m gonna need a completely clear cornea because I’m
gonna be able to see through it. If I can’t see through it, I can’t do surgery.
And the cornea also- most people don’t realize it- but helps to focus the images
on the retina. Typ- typically people always think about the lens doing that
but actually the cornea does that as well. And if you think about it, people
that get LASIK or LASEK, that’s what they do. They change the cornea so that the
light is now focused different onto the retina and then hopefully people won’t
need glasses anymore. The iris. Of course I love this picture of their blue eye
and brown eye. And the iris is an important structure as far as regulating
the amount of light that comes through into the eye by constricting the pupil. It’s typically round in the dogs and it’s kind of a vertical slit in the
cats. Now as animals age, and this is very common in certain breeds like, for
instance, a miniature poodle, as they age it’s not uncommon that the iris loses some
of its normal tissue. And it really doesn’t mean a whole lot but it does
mean that the pupil get bigger and there are some animals that actually may
become a little light-sensitive because of it. It’s not common but it can
sometimes happen. But if the iris loses a little bit of its normal tissue and the
pupil gets bigger, then that means you can also see more of the
structure- of the structures, is like the lens behind it and we’ll get to that a little
bit later. Now we finally get to the lens. It focuses the light onto the retina. It
is held in place by these tiny little zonules. 360 degrees. It hardens with age.
The lens keeps growing during life. It cannot possibly get any bigger because
otherwise eventually all our eyes would explode if we were getting bigger and
bigger, so instead it gets- it starts growing almost like inside, where it
hardens. It becomes more and more compact. As it grows, it kind of just pushes the
other material a little bit more in the center. Now that is something that
happens in all of us. At some point of time, it doesn’t matter who you are,
you’re gonna need reading glasses. I know I have them and that’s exactly what
happens in nuclear sclerosis. This lens gets harder. It’s not as flexible anymore
and because of that, you’re gonna need reading glasses. Same thing happens in
dogs and cats. They don’t need reading glasses but it does happen. A cataract is
a true opacification and we’ll talk about that more. The vitreous is a gel-
like cushion between the lens and the retina and it can slowly become more
fluid as the animals age. Now this seems a very weird picture probably but this
is a vitreous in a dog. It has lots of little vitreous floaters. I’m sure
there’s a number of you in this room who have vitreous floaters. They are very
annoying especially in that bright light condition. I have them and it’s just,
again, it’s part of like, “Well, at some point in time you get a bit older and
that’s- that’s okay.” But this dog, of course, had very, very
significant- it doesn’t seem to bother the dogs like it bothers people, so
that’s a good thing. The retina. It’s so funny because we
always say it’s like the film in the camera.
And then I was realizing I have a 14 year old daughter who has never seen a
camera with film in it so we will know what we mean but the younger generation-
I guess I’m gonna have to figure out something else. But they basically
receives the image and then sends it to the brain and then the dog and the cat
have a reflective structure in the back of the eye.
It’s called the tapetum and that is something that you and I don’t have. The
reason why if you don’t have the red- red-eye focus thingy set on your
camera, you get these red pupils because we see the structure of the back of the
human eye, which is typically full of blood vessels and gives a red
appearance. If you think about, sometimes you may see it in your dog or cat at
night where they got a little bit this green reflection or the
deer-in-the-headlight with their incredible reflection. That’s this
structure, the tapetum, that is doing that. It helps increase vision during dim
light conditions so it especially developed in animals that are more
nighttime animals than we are. We come to the cloudy eye. Is it a cataract? Like I
said, there’s a number of reasons for an eye to be cloudy. There could be either
extra fluids called corneal edema in the- in the cornea. It could be scarring,
significant scarring. If you have a lot of corneal ulceration, scratches on the
cornea, every single time that cornea heals, it can leave a scar. So that could
be a reason for cloudiness as well. There could also be some material in between
the space between the cornea and ours and I have examples of all of them. If
you have severe inflammation of the iris, that can also look very cloudy. And
then if we move deeper in the eye, the cloudy lens, which could either be
nuclear sclerosis or cataract. This eye- a lot
of people would say like, “Oh, your dog has a cataract.” Well it actually doesn’t
because this is not the lens you’re looking at. This is one of the times
where you can actually see the cornea. You’re not supposed to be able to
actually see the cornea because you’re supposed to see right through it but
there’s extra fluid right here in the cornea. There are some vessels here and
because of that, the eye is so cloudy. That could also be material in between the
cornea- and the cornea right here- and the iris. There’s a little bit of bleeding
inside here and it could be some inflammation in there as well. And this
is my boy. He is- I got him from the shelter about 11 years ago. They said he
was one, he was probably a little bit older, so he’s getting up there in age
and it was so funny because I walked in and I saw this dog, I’m like, “That’s like
my dog!” So anyway, he’s got some pretty significant nucleus sclerosis. It’s a
normal aging- again, a normal aging process of the lens. In people it starts
happening above the age of about 40. It presents in dogs after six years of age.
Cats at an older age, a little bit more variable. Like I said, we need reading
glasses. Dogs and cats don’t need that but it can be very easily confused for a
cataract in older animals because it does give that kind of cloudy appearance.
It doesn’t affect vision significantly. However, I have found over the years that
it seems like these dogs that are- dogs that are really getting to be senior
citizens. It’s not uncommon. They may walk towards the food bowl and then use their
nose for the last little bit to actually locate where that is. Also, if you try to
give him a treat, it’s probably better to pull it a little bit further away from
them because they can see it better. If you hold it too close, they may
really have to use that nose to try to find it. So if you read the literature,
all that stuff is not supposed to happen in dogs but literature is sometimes not
always reflective of what happens in real life and I definitely do see that. But
there’s really nothing we can do about it and it’s just something to be
expected as they get to reach senior citizen age. So this is him again in his
favorite position and that’s his eye. Well he usually likes to be right on the
couch there but- and that’s his eye. I mean it really looks very cloudy and I
do look at him once a year just to make sure he doesn’t have cataracts, but he
really does not have cataracts. It’s just all the normal aging change. And then we
get to the next reason for a cloudy eye. A true cataract. A true cataract-
opacification of the lens or the lens capsule. It can be a tiny spot of
cataracts and they’re very common in older dogs. If you bring a dog to me
that’s more than ten years old, I will probably find a little tiny spot of
cataract. No big deal. There’s nothing we need to do about it, don’t worry about it.
But if it starts to affect a large part of the lens, then it really can start to
interfere with vision. Like this dog, this lens is- has a huge amount of cataract so
that really can interfere with vision. So we get to the cataract. The classes of
cataract formation- and this is my other dog. This is Hudson and this is Bella.
Hudson, I’m not really worried about him getting cataracts and the reason for
that is, is the number one reason for cataracts in dogs is something in their
genes. That really is the most important reason. And he is a pitbull-
labrador mix, I’m not worried about it. Her though, she’s a little miniature poodle.
Oh yeah, she- she is definitely more at risk than him for getting a cataract
as she gets older. So guess what? I’ll be checking her regularly as well. There is
genetic testing available for many breeds. The age of onset is very breed
specific. Sometimes I see in cocker spaniels, I see animals that are blind
from cataracts before they are one year of age. If you have a Bichon, they typically
tend to be 4 to 7 years of age. Miniature poodle, frequently 10 years and plus.
So it depends a little bit on the- on the dog breed as to what age should
typically start. A common question that I get, “Is my dog not way too young for
cat- getting cataracts?” And because that’s what you think in people.
Cataracts you think something as you age, your grandparents, they get cataracts. But
in dogs, because the number one reason is something in their genes, it can happen
at a much earlier age. The second most common reason is secondary to diabetes
mellitus and that is more common if the diabetes is difficult to control. There
is a study- it’s an old study- but it says that about 50% of the diabetic dogs will
develop cataract within one year of diagnosis of the diabetes and about 80%
of them within two years of diagnosis. I don’t think honestly it’s quite that
high but there is definitely a chance that in diabetes you can get secondary
cataracts. And those cataracts secondary to diabetes tend to come on very quickly
meaning the genetic cataract frequently- kind of they develop slowly over months,
sometimes years. The diabetic cataract can literally go from having fine vision
to almost no vision just a couple days later. Doesn’t always happen but it
certainly can. Then there’s all the causes for cataracts as well. Secondary to
inflammation inside the eye. If you notice this is not a nice round pupil
that is because the iris is stuck secondary to inflammation. It can also be secondary to diseases deeper inside the eye,
certain retinal diseases. Trauma can cause cataracts as well. It’s
really not that uncommon- not that common honestly. And then there’s more uncommon
things like a puppy bites an electrical cord, gets over that, but then six months
later develops a cataract, so there’re- there’s some unusual reasons for
cataracts as well. When we talk about stages, there is something called the
incipient cataract, which is basically the earliest beginning and this is actually
a little bit bigger than typically incipient. But incipient will be like a
little dot here or a little dot there and it’s a small cataract. It doesn’t
interfere with vision and it can go unnoticed and those are typically the
cataracts that we see in dogs as they age. It’s just little tiny spots of
cataracts, no big deal, we don’t worry about them. They can of course progress
and become larger and then become more significant. The next stage is immature
cataracts which means that slowly over time, more and more of the lens will
become involved and again, initially, we may not have any issues with vision, but
as the cataract grows, you can slowly start to have seen problems with vision.
Where initially you might notice that, you know, maybe sometimes he doesn’t
quite want to catch the toy as well or fetch the ball and then you go like, “Eh, she’s getting old,” or, “He just doesn’t want to do it anymore,” and then
at some point in time you might notice, “You know, he’s walking slower,” and then at
some point in time you might notice that, “You know what, he just bumped into
something that he should have seen,” and that’s kind of like as the cataract
progresses, you can get more of that. A mature a cataract is a blinding cataract,
meaning there’s no-there’s light that comes through but no real vision and the
entire lens is involved. At that point in time, that eye is blind. A hypermature
cataract is something where the lens starts
doing when a grape turns into a raisin.
It starts shriveling up and sometimes, especially in young animals, it can
actually do it to the point where you can start to see the reflection of the
back of the eye again and we can start to have a little bit of return of vision.
That is very uncommon in the older dogs but sometimes a really young one,
like- like I mentioned, some cocker spaniels may have cataracts before they’re one year
of age, they might actually spontaneously reabsorb these cataracts and get some
vision back. What are we gonna do for cataracts? Well there’s all kind of stuff
on the internet. If you put anything in Google, you get lots of stuff. All these
drops and medications that promise to resolve the cataracts and there’s all
kind of nice picture- I just pulled this off the internet- where you have a
cataract there and no cataract here but guess what? This is a really tiny pupil
so maybe it’s just the pupil that is here constricted. I don’t know but what I
do know is there’s a couple products that have been studied and none of them
have proven to have any significant effect. So that’s what I typically tell
people. It would be great if they came up with something but no. So what are we
gonna do? Potentially cataract surgery. Now there’s two things. The eye has to be
a good candidate. Like I mentioned earlier, if I have a lot of corneal
scarring and I cannot see through it, I can’t do surgery. So it’s very good-
important to get a good, thorough ophthalmic examination to determine if that eye is a
candidate for surgery. And the dog has to be a good candidate because they’re
gonna need eye drops four times a day for several weeks and then slowly
decreasing over several months. They’re gonna need medications by mouth
and if that’s a struggle for every single drop, no. Then don’t even bother.
So we are going to meet Niles. This was Niles, a little dog that had
cataracts secondary to diabetes and Niles underwent cataract surgery. Now
before we do cataract surgery, there’s a couple things we have to do. The first
thing we do is we do an electroretinogram to make sure the
retina functions normal cause if their retina behind the lens doesn’t function
normal, taking the lens out is not gonna help. So that’s the very first thing
we do. And this is typically what we look for. It is- we want to see a nice big wave
like that. That’s good. We don’t want to see a solid line that goes like that. We
don’t want that. And my boy showing how we do that.
It is either no sedation or very light sedation. It’s not painful in any way but
they have to sit still. So some of them there are too wiggly. We may have to give
just a little bit of a sedative but we sit with them in the dark for about 15
minutes to allow their eyes to adjust to the dark as much as possible and to
become as sensitive as possible and then the equipment flashes light at the eyes
and the computer records what the retinal response is. And then we’ll know
right away whether or not this would be an acceptable candidate for surgery.
Another thing we do, we do an ultrasound on the eye to make sure there’s not a
retinal detachment or other abnormalities. And this is actually an
ultrasound from a normal eye where this- I know it looks like just a whole
bunch of black and gray- but this is basically the eye. This is the lens
sitting here. This black area is the vitreous and then the retina is sitting
here and it’s- you can’t really distinguish it which is good because
it’s nicely plastered against the back of the eye. That’s what we want. What we
do not want is this. We have a lens here which has a cataract and then we have
the retina floating around like that. We don’t want that so we do an ocular
ultrasound as well. Now what do we do during surgery? We use a process called
phacofragmentation. It’s not using lasers- that’s a very common
misconception- but we basically do the same thing as they do in people where
basically the ultrasound- the cataract’s lens is broken up in many little, tiny
fragments that the machine then irrigates and aspirates and flushes out of
the eye. It’s of course performed in a general anesthesia in dogs and cats. It’s
not like in people where they just tell you to lay still, you give- give you a
topical anesthetic, and that night you go out to dinner again.
Yeah no, not so much. So what do we do during surgery? Well this is the eye at
the beginning of the surgery. First make an incision right along the area that we
call the limbus where the sclera and the conjunctiva joins the cornea and make a
little groove there. And then we make a little with- first with the needle and
then it’s a special forceps- we make a little opening in the lens
capsule and then with this- this is the phacofragmentation probe and I
basically start carving out this lens. I start removing all the cataract’s
lens material until it’s all gone and then here we have the hole in the
front of the lens that I made. These are some plaques that sometimes happens in
dogs where they have little calcium deposits and there’s really nothing you
can do about them but they tend to not bother the dogs. And then if at all
possible, I put an artificial lens back in place
again. I fold this thing up actually and then I inject it into the eye and then
it unfolds and then it sit there and then, of course, we suture it up and then
we’re done. The artificial lens. It’s not always
possible to put artificial lens in. I would say 95% plus of my dogs get an
artificial lens but what happens, as you can tell, we basically open the existing
lens, we hollow it out, and then put an artificial lens back inside that capsule
again. So you’ve got to have a healthy capsule that is held in place with
little tiny healthy zonules, otherwise I cannot put an artificial
lens in. If we can’t put an artificial lens in it doesn’t mean that the eye is
blind, it means that there is just- if everything goes well we have far vision
but no close up vision. Aftercare. Lots of it. I always say your job starts when the
dog goes home because there’s gonna be four times a day eye drops and I just
collected some of them- we see an antibiotic, this is an corticosteroid-
those will always be. Sometimes we also use a pupil dilator or sometimes, if
we have a little bit of an issue with pressure inside the eye after surgery, we
may use- need to use this for a bit but initially we start at four times a day and then we slowly decrease but they’re typically on medications for at least
four to six months after surgery. There are some animals that are on medication
for life, not four times a day, but maybe like once a day or something. We also
send them home with medication by mouth. Typically an anti-inflammatory as well
as an antibiotic and those are short courses, so within the first couple weeks
those are done. We also need to put one of those lovely plastic cones on. It has
to be the old-fashioned, hard plastic cones. Dogs are way too smart. If you put
one of these nice soft cones on or a doughnut or something like that, they
very quickly figure out how to flip that thing back and then find a nice edge and
start rubbing their eyes against it. So that’s why it’s gotta be this
old-fashioned, hard plastic one. And then aftercare, they kind of need to do this.
Keep calm. Sleep a lot. It’s very good. We don’t want them running, playing, jumping.
We don’t want them playing with other toys. No roughhousing, no toy shaking, take the
toys away. They cannot have a bath for several
weeks as well. They kind of need to be an old dog for a couple weeks which is
sometimes tough, especially in the ones that see right away after surgery,
they’re ready to go. They want to- they want to see stuff, they want to explore,
and you kind of have some, “Not yet, not yet, your time will come.”
Rechecks. We need lots of rechecks. Again this is Niles on the top before surgery
and this was on one of his rechecks and it’s every few weeks in the
beginning and then after that it’s less, but it’s typically is once or twice a
year after that for the rest of the dog’s life because there is always a
potential for complications later. So here we have Niles again two weeks after
surgery. I like to see that twice. He was a happy dog. Success rate and
possible complications. Success rate of cataract surgery in dogs we typically
say is about 90%. Now what that means, it means that nine out of ten eyes get
good vision. Not perfect vision, but good vision. But honestly you have to turn it
around because it does mean that one out of ten eyes, despite everything you put into
it, either may never regain vision or initially
has vision but then loses the vision, again, secondary to complications. The
complication rates of cataract surgery in dogs is definitely higher than in
people. The dog eye does not like to have anything performed on it. The person’s
eye is much more tough and can tolerate a whole lot more than dog’s eye. There’s
also some breeds that have, that we know, have not as great a success rate as
others and the Boston Terrier is one of them where they’re much more prone to
getting complications so those will be one of those briefs where you go like, “I
really probably would not even consider surgery until the dog is
completely blind from its cataracts.” So. And then some minor complications.
We sometimes- we get a little corneal ulceration, a scratch in the surface, and
that can heal just fine with some medication.
We typically here at the AMC always keep the dogs overnight because some of
them will get just a transient increase in intraocular pressure and we need to make
sure that we treat that. Both of those things should resolve and they shouldn’t
be any lasting things. There’s also major, potentially blinding
complications and the three biggest ones are glaucoma, a high-end drop in pressure,
retinal detachment, or excessive scarring around the artificial lens.
Rare. Then there’s always rare things like intraocular infections or severe
corneal ulceration. Those are really rather rare. If we talk about glaucoma,
glaucoma is a sustained increase in intraocular
pressure in dogs, cats, people. The reason why I hesitated for a moment because it
is so much worse in dogs typically than in people. A lot of times glaucoma in
people can be fairly easily- and I guess I should not say that because in some
people it cannot- but in a lot of people, it can be controlled with just
medications once or twice a day for a long time to come.
Glaucoma in dogs can be much tougher to control meaning, that the chance of them
actually losing vision to it is much greater than in people because what a
glaucoma does, it damages the optic nerve and it’s not only blinding but it’s also
painful. So even if we lose vision, we still have to do something about
glaucoma to make sure that that eye is comfortable. Another thing that can
happen is retinal detachment. We always check to make sure it’s not a retinal
detachment before surgery but it can still happen after surgery as well.
Retinal reattachment surgery is possible in dogs. This is not a painful proced-
this is not a painful complication. Can be blinding but it’s not painful. And
then if we look at this- every dog will develop some degree of scarring of its
lens capsules after cataract surgery. It usually does not interfere with vision.
That’s why a lot of dogs after surgery, you still see some little white spots
and that’s okay. It doesn’t bother their vision, it’s just some degree of scarring.
Happens in all of them. In some of them, they get excessive amount of scarring
and if you get a lot of scarring, their vision may be impaired by it. I must say
it is more common to get excessive scarring if people just don’t bother
about giving the eyedrops than if they’re very good about it. That’s one of
the reasons why I always stress the aftercare because it is so important. And
cataracts in cats. Cataracts in cats, like I said, a lot
will be the same whether you’re a dog or a cat but there’s some differences as
well. Remembering dogs, the number one reason
was something in your genes. The number two reason, secondary to diabetes
mellitus. And then the other reasons come way further down. In cats, the most common
reason is chronic inflammation of the iris called anterior uveitis. Hereditary
cataracts, I see them, but is much less common in cats. It’s really quite rare. I
mean, I maybe see one cat a year so it’s very, very uncommon.
Like I said, chronic inflammation is usually the reason for a cataract in
cats. It’s often just in one eye and the other eye is completely fine so for that
reason we don’t do surgery as often as we do on dogs because cataracts, if it’s
just in one eye in a cat, you would hardly not know that there’s any issues
with the cat. I mean they still jump on top of the refrigerator
even with one functioning eye so we don’t do cataract surgery as often
in cats as we do in dogs. But surgery itself is similar. We do the electroretinogram,
we do the ocular ultrasound, and there is an artificial lens specifically made for
cats. We have dog- we have various dog artificial lenses and then we have a cat
artificial lens as well. Aftercare and rechecks are the same for a dog or a cat
and I’d be happy to answer any questions. Jaclyn: So thank you very much Dr. van der Woerdt.
We’re gonna take some questions but I just wanted to share as I was coming up
here, I was talking to one of the vet techs in the elevator and she said,
“What’s going on tonight?” and I said, “We’re talking about cataracts with Dr. van der
Woerdt,” and she said, “Oh that’s my- my favorite surgery to be there for in our
recovery area,” which was called the beach. She said because you’re holding them as
they’re waking up and you can just see in their faces, they can see again and
they look so happy and so excited and usually they don’t want to run around
right after surgery but these animals after they have their cataract surgery,
that’s when they’re most excited. So she said, “That’s my favorite,”
and she got so excited talking about it so I just wanted to share that.
Kimberly if you want to just hand me a question so we can get started, I know
you’re gonna sort back there. Just do a little random first. Okay. A question
about cloud- cloudy eyes and cataracts in rabbits. Dr. van der Woerdt: Ah good one. Cloudy eyes and
cataracts in rabbits. Rabbits are a different story again in that a cataract
in a rabbit is not uncommonly associated with a bug called
e cuniculi and you have to test for that first and potentially
address that. Cataract surgery can be done in rabbits but it is one of those
things where anesthetizing a rabbit certainly has its risks. There is no
doubt about it. So if it’s- again, if it’s a cataract in just one eye, we’re less
likely to want to pursue it than if it’s in both eyes. But yeah the rabbits are a
very different story. Jaclyn: Thank you. We have two questions here about- do you perform
surgery on both eyes at the same time or on only one eye at a time, wait a little
bit of time? How do you usually go about that? Dr. van der Woerdt: If both eyes are affected to the point where they interfere with vision, I’m
doing both at the same time because that way- which is very different from people-
but that way we only have one anesthesia, we only have one time all the rechecks,
and whether you give your drop in one or both eyes, it’s the same amount of work.
So yes, if both eyes are affected, we do them both at the same time.
Jaclyn: Is there an age limit for surgery? Is there a cut-off where you don’t recommend
surgery? Dr. van der Woerdt: Nope, it all depends on the dog. I think the oldest I’ve done has been 18
and a half. No that’s not common but there is not necessarily a cut-off.
Of course, as they get older, we do have to make sure that everything else is
okay so it is more important to do a good physical examination, routine blood
work, maybe a radiograph of the chest to make
sure that that is all in order, but yes. I mean, just the fact that the dog is 15 or
16 does not tell me like, “Oh no, we can’t do surgery on that. Jaclyn: Wonderful. Can
cataracts be diagnosed during the first visit to the vet? Dr. van der Woerdt: To- to me or to your regular veterinarian? Jaclyn: To you, to an ophthalmologist. Dr. van der Woerdt: Yeah, oh yeah.
Jaclyn: Okay. So usually the process is you see the
general vet. The general vet refers to- Dr. van der Woerdt: Correct
Jaclyn: -someone like you? Dr. van der Woerdt: Or you might have
noticed yourself, that you notice a difference in changing vision as well as
cloudiness and you go, “You know what, I’m just gonna have to have it checked out,” and then,
indeed, you would come or your veterinarian would send you and that’s
at that point in time I’ll tell you, “Don’t worry about it, this is just an
aging change,” versus, “Yeah we’re starting to get some cataracts.” Jaclyn: Is discoloration
in one eye, such as partially blue, partially brown, an issue? Are they- does
this mean they’re predisposed to eye issues? Dr. van der Woerdt: Nope, they’re not. It’s just cute.
There are certain eye conditions that are a little bit more common in like the
blue eyed dogs but generally speaking, if it’s just a dog with a blue eye and a
brown eye, the vast majority of time that blue eye’s just fine. Jaclyn: You have one
question here. We’ve heard that Havanese are prone to cataracts. Is this the case
and are there any preventive measures they can take? Dr. van der Woerdt: That’s a good question
actually. Twenty years ago when the Havanese was a very, very small breed, I
saw a lot of cataracts. Now, through a lot of good breeding, I would say the
incidence of cataract has significantly decreased. There’s definitely still
cataracts but I see cataracts in just about any breed but not nearly as much,
again, as like 15-20 years ago. Can we prevent it? If a cataract is gonna form,
it’s gonna form. There’s nothing we can do to prevent it. The
prevention truly is to try to do- to try to get the dog from, like, a good
breeder that’s really focused on trying to make sure there’s no cataract in the
line. Doesn’t mean that the cataract may not come but it just makes the chance
less. Jaclyn: And does the success rate for treatment of surgery differ by breeds? Do
some breeds do more- do better than others? Dr. van der Woerdt: Yes, there are some breeds, and
especially the Boston Terrier, where I’m just always more cautious about success
rate. Other than the Boston Terrier, in my experience, there’s not that many other
breeds in which I would be concerned about, but the Boston, yes I’m concerned. Jaclyn: Can you perform surgery on a dog with a
heart murmur? Can- does, is that allowed? Dr. van der Woerdt: It all depends- can everybody hear the questions by the way?
All right. It all depends how bad the heart murmur is. We just- just this
afternoon I did cataract surgery on a little dog with a small heart murmur. Our
cardiology service did an echocardiogram and yes, the murmur is definitely there
but it was not significant for the function of the heart. So at that point
in time was not an issue at all. There are of course some heart murmurs that
are associated with significant heart disease and then cataract surgery or
general anesthesia in general may not be recommended. Jaclyn: Can congenital blindness be
cured in dogs or cats? Dr. van der Woerdt: Congenital blindness is rather uncommon and it all
depends what the reason for it is. I would say I can’t think of a single
thing that would make an animal be born blind that I could cure. Because if an
animal is born blind, that usually means there’s a lot of different things wrong
within the eyes. So it’s fortunately uncommon for that to happen in both eyes.
It’s more common for one eye to be very abnormal and blind from birth and then
have a completely normal opposite eye. Jaclyn: For long-haired dogs and
cats, should they always have their hair away from their eyes? Is it good to keep
them trimmed to avoid any scratching or-?
Dr. van der Woerd: I think so. Yeah I think so, I definitely think so.
Keep those hairs around his eyes short so that they don’t- because they can
actually get so long that the hairs turn around they poke right in the eye so I
love the little bows on top of the head. Anything to do to keep these hairs out
of their eyes, yes. Jaclyn: Do- have you ever seen macular degeneration in animals?
Dr. van der Woerdt: Actually animals don’t have a macula so, no. Jaclyn: That was an easy one. Are you more
likely to recommend surgery if there is bilateral cataracts? Dr. van der Woerdt: In the end it’s
always the owners decision whether they would like to pursue surgery or not. If
there is cataracts in both eyes, then the reason to want to do it is stronger than
if there is a cataract in one eye but sometimes we have a cataract- let’s say
we have a six year old dog with cataract in one eye and the other eye is
completely normal. The other thing about cataracts and
cataract surgery that I did not mention, there is definitely kind of a window of
opportunity and the reason why I say that, as the cataract is in the eye,
certain things start happening and secondary to that, the success rate
starts to decrease as time goes on. So if we do- and that window is much shorter
in the diabetics than in the non-diabetics. So if I have, for instance,
six-year-old dog, cataract in one eye, completely normal other eye, we have
either basically one of two options. One is to do surgery, one is not to do
surgery, and there’s reasons for both. The reason not to do surgery is because
the other eye is totally fine. An animal can function very well with one eye. Of
course, they would like to have two but it can work- function very well with
one eye and the good eye may never get a certain cataracts. The reason to do
surgery is because, if all goes well, then we have
vision in both eyes again which, of course, any animal would like. And also a
reason is this dog is six now. It’s probably an okay candidate for
anesthesia. It is still healthy enough that we don’t expect much unusual
complications from that. What if the other eye developed a cataract when the
dog is 12? If we’ve done this first one and everything went well, then we have
vision in this one and then maybe if the dog develops a cataract when it’s much
older in the other eye, then at least we have vision in this eye. So like I said,
there’s reasons to do surgery and there’s reasons not to do surgery. And in
the end, everybody has to decide what’s right for them.
Jaclyn: Are there any vitamins or supplements you recommend for animals to just have
good vision? To keep them- their eyes healthy like there are for people?
Dr. van der Woerdt: Nothing in particular. Jaclyn: Okay. We have someone who’s asking about-
I think this is a medication called lanosterol. Have you heard of any
research on this? Do you think it’s promising? Dr. van der Woerdt: It is one of these things that
I mentioned. Yes, there is some research done on it and for everything that I’ve
seen, it convinced me that it had no effects. Jaclyn: Okay good to know.
Can the iris get freckles like brown spots on it?
Dr. van der Woerdt: Yes it can and that is
something to be concerned about in cats actually, because in cats, sometimes these
freckles, they can turn into a malignant tumor called melanoma. It’s not so much
we worry about in dogs but that’s specifically a cat. So if you have a cat
with a nice golden green iris and you start noticing pigmented spots, that
will be something to have evaluated. Jaclyn: Okay, we have a question from someone on
Facebook who asked what role does nutrition play in preventing or slowing
down cataracts? Dr. van der Woerdt: It’s a good question and I think any
good nutrition is good, meaning what I’m trying to say- you can
get cataracts with certain severe deficiencies but if you feed your pet a
well-balanced diet, then I think you’ve done everything from, diet-wise, to try to
prevent cataracts because there’s really nothing that’s been shown to really
decrease the incidence of cataracts, a nutrient supplement wise or anything.
Jaclyn: Also a Facebook question, if a cataract looks calcified in a senior dog is there
a recommended surgery protocol? Dr. van der Woerdt: If a cataract sometimes- remember at some
point of time in the- in the lecture, I showed a picture of what we call the
hypermature cataract, where the cataract started shriveling up. Sometimes you can
also get these calcium plaques which is actually one of the things that I showed
in that one picture after cataract surgery. If these plaques are minor they
are not a big deal. If the plaques are more significant, then sometimes we try
to take them out during surgery. If the plaques are really significant, then we
may have to take out so much that we cannot put an artificial lens anymore. Jaclyn: If you catch a cataract early, is it better to perform surgery while it is still
small and will it grow back if you take it out too early? Dr. van der Woerdt: That is always a good
question. I personally like to wait until I am convinced and the owner’s convinced
that this cataract’s going to progress to blindness. The animal doesn’t have to
be blind but I want to be convinced that, within time, that eye is going to be blind.
And the reason for that be, is I’m very cautious at 90% success rate but there’s
10% failure rate and the one thing I don’t want to do
is make matters worse. So once I’m, everybody’s convinced that this cataract
is growing, is developing, is only a matter of time before the eye is going
to be blind, then we can do surgery. Jaclyn: And is it ever too late,
like you’ve caught the cataract too late and surgery just won’t help? Dr. van der Woerdt: Yes that can
happen. Like I said, eventually a cataract does when a grape turns into a raisin. Starts shriveling up. And then secondary to that, you get secondary complications
inside the eye. Sometimes the retina starts degenerating, so yes there is definitely
this window of opportunity where if you wait too long, it may no longer be a
candidate for surgery. Jaclyn: All right so we’re gonna have one more question. How do you
determine the visual acuity in dogs and cats? Dr. van der Woerdt: That is very difficult and
truthfully we can’t. There are certain- we can do a technique called retinoscopy
where you basically refract a dog or a cat, same as they would do in people, but
still, we can’t read their- in research setting, they are certain, like,
navigational devices that animals can, like, choose so they can pick and choose.
So we can kind of assess vision but there really is no great vision testing
in animals. It remains fairly crude. Jaclyn: Wonderful. Well thank you very much Dr. van der Woerdt for your time. Dr. van der Woerdt: You’re welcome.

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