Good evening everybody and welcome to tonight's webinar. We are in for a treat again. This series of 4 has been absolutely fabulous, and, tonight is no exception.

For those of you that are unaware, it's, tonight's webinar and the series has been sponsored by TM UK, you may have heard me say before, we need to support those that support us. TVM have been very generous with their sponsorship of these webinars. So, let's show our appreciation by supporting them.

Little bit of housekeeping for those that haven't been on with us before. If you have any questions, just run your cursor over the screen and you'll see a control bar pops up normally at the bottom. There's a Q&A box.

Click on that, type it in. It'll all come through to me. And Ron has very kindly agreed to, to take those questions at the end.

So by now you probably know Ron. He holds a PhD in veterinary ophthalmology and he's currently a professor in veterinary ophthalmology at the School of Veterinary Medicine at the Hebrew University in Jerusalem. He's also a very popular international speaker, having been invited to talk in more than 30 countries on 6 continents and lecturing in continuing education seminars, national meetings, and world congresses for general practitioners, including the BSAVA, SEVC, WSAVA, WVC, and NAVC.

Ron, welcome back to the webinar vet and it's over to you. Thank you very much, Bruce. I join you in thanking TM for sponsoring tonight's talk, and I thank everyone in the audience for joining us tonight.

As Bruce said, this is the 3rd webinar in the 4th part series. Last week, we discussed medical treatment of corneal ulcers. And unfortunately, as you know, medical treatment is not always successful.

The title of the talk is 0.5 millimetre is all you get and that's cause 0.5 millimetre or 500 microns is the thickness of the cornea.

You don't have much of a safety margin to begin with. You don't have a lot of time for the medical treatment to take hold, so often it's it, it is successful, but sometimes the ulcer is just too deep or too contaminated. Maybe it's this me to about to perforate, maybe it has perforated.

This patient has to go into surgery and that's what we'll be talking about today. As always, I'm asked by webinar vet to declare that they have no financial relationship with any products mentioned in tonight's talk. But once again, I remind you that it is sponsored talk and again I thank TM for sponsoring it.

However, while I have no financial relationship to disclose, I should disclose, or what some would call Seamus advertising, disclose the fact that many of the pictures in my talk are taken from a book I've co-authored along with David Maxs from UC Davis and Paul Miller from University of Madison, Wisconsin. Besides making this disclosure, I should also make a disclaimer. And the disclaimer is that this talk will not turn you into a corneal surgeon.

Corneal surgery, or I should say corneal microsurgery, requires magnification, preferably a surgical microscope, which you may or may not have in your clinic. It may require fine suture material, 80 to 100, and the proper instrumentation to work with fine, sutures like that. And above all, it requires intensive training.

It is something we teach during a residency programme over 3 years. It is not something we teach in a weekend course. It is not something that we teach in a 1 hour webinar.

So the aim of this talk is not to make you a corneal surgeon, but it is to make you more knowledgeable. About the surgical options cause you are the veterinarian who will be referring these cases to your ophthalmologist. You want to discuss surgical options with the owners, tell them what to expect, and you want to be able to discuss the various options with the veterinary ophthalmologist who will actually be doing that surgery and hopefully by the end of today's talk, you will be able to discuss these topics more knowledgeably.

So what should we be talking about? We should talk about curatectomy, both superficial and deep. We should talk about conjunctival flaps.

Two variations of conjunctival flaps are corneal cordjunctival transposition and biological scaffolding that we'll discuss. We'll talk about other procedures including corneal lacerations and penetrating keratoplasty or corneal transplantation. And towards the very end, I'll get into a couple of procedures that yes, you are able to do in your clinic without special equipment or training.

I'm referring to corneal glue and to treatment of boxer ulcers. But before we get to that, let's start off as I said, by talking about keratectomy. In keratectomy, basically we are removing a superficial or a deep layer of a cornea.

Superficial keratectomy is indicated in the following situations, feline sequesttrum or a necrosis of the feline cornea, which is this black lesion that you are seeing here. We are talking about dermoid, which is an ectopic piece of skin that grows on the cornea, actually doesn't grow on the cornea, it's a congenital lesion. Puppies may be born with it.

It's non-progressive, so I was wrong to say it grows on the cornea. But puppies will present with this ectopic dermal tissue or we see the hair here is irritating to the cornea and the lesion has to be removed and another indication is limbble melanoma. You can see.

The melanoma here invading the cornea from the limbus and this can also be removed with a superficial chaatectomy. Broadly speaking, here is a before and after picture of superficial corectomy. So we have a corneal sequesttrum in the cornea of this cat and here it's been removed.

As you can see, it is removed by the surgeon making an outline in the cornea around the lesion. We're making incisions in healthy cornea around the lesion, then picking up one corner and undermining all of the necrotic tissue that we want to remove. So we start out with this lesion and we end up with a rectangle.

The lesion was here. Surrounding cornea and the lesions have been removed. Here is the diagram, so as I said, we take our blade, we make an outline of a rectangle or square around the lesion.

We grab a corner once we've out of the outline that we incised and then with our blade we start undermining the tissue, lifting it with the forceps as we make progress and eventually cutting it away. So this is a drawing and basically this is what it looks like under a surgical microscope. We use a special blade called a keratome which helps us stay in the same plane in the cornea.

You may remember from my talk last week and I'll show, in a minute a picture of corneal histology. The cornea is composed of parallel. Layers of collagen fibres and it's a parallel arrangement that helps maintain corneal transparency.

So as we are cutting away the superficial layer of the cornea, we want to stay on the same plane. We don't want to move from one plane to the other because that would cause us loss of corneal transparency and this special blade, the keratome helps us remain in the same plane. So we're grabbing one corner of the tissue we're about to remove with our forceps and just Removing, undermining the tissue that we want to remove.

So this is what it looks like under the microscope and another view, lifting the tissue and undermining it as we are cutting along. I should mention that Don would be placing links to a couple of video movies, in the discussion box or mailbox of this presentation, so you can watch a movie of this, procedure being done. If we have time at the end, I will screen it with some commentary.

If not, you can watch it yourself, but there is a 5 minute movie showing you how it's done. I say that sequesttrum limbble melanoma and dermoid can be removed with superficial keatectomy. I didn't really define what is superficial and it's really funny to talk about superficial keatectomy when the width or the thickness, I should say of the cornea is just 0.5 millimetre.

Again, not 0.5 centimetre. 0.5 millimetre, 500 microns.

So we are talking about removing just superficial layers from these 500 microns and basically superficial keratectomy is defined as anywhere up to 30% of the cornea. Anything deeper than that is deep keratectomy. So when do we do deep chaatectomies, that's when the lesion is deeper.

That's when we have a corneal abscess, such as the two abscesses that you are seeing here. You want to remove. The entire abscess, you can see that it in both cases involves more than 30%, so we are going to perform a deep creectomy on these patients to remove all of the inflammatory and infected material and therefore we are going to create a huge defect which unlike superficial curatectomy, we are going to have to fill.

And feeling the defect we are creating with a deep arectomy brings me to the next type of surgery that I want to discuss and that's a conjunctival flap. So when do we do flaps in phalic surgery and why do we want to do flaps? The three indications for flaps are shown here.

The first is a very deep ulcer or a dematocele, which is what's shown on your left. You may remember from my talk last week that they said that one way of recognising it's a dematocele is the fact that the cornea, or oops, sorry, the cornea around the lesion is a dematous, there is fluid here, but the lesion itself. Because it has reached down to the level of the decimates membrane, there is no stroma to hold the fluid.

Therefore, there is no edoema. Therefore, the centre of the dematocele is clear, which is what you are seeing here. So this dematocele obviously needs to be filled in with some kind of flap.

Here is another indication, a contaminated ulcer or melting ulcer. We discussed that last week. The proteolytic activity of proteases and colagenases that are secreted by infected infectious organisms, by the tears, by leukocytes that cause degradation of the corneal stroma.

You can see that this cornea has a Mushy appearance to it. It's actually being degraded by enzymes as we are looking at it, so a contaminated cornea, a melting ulcer or a corneal abscess such as you're seeing here and such as I showed you in the previous pictures, you're removing an abscess, you're creating a defect, you are going to have to fill it with some kind of flap. So when we take these patients with the dematocele and the contaminated ulcers and the abscess into surgery, Before taking them into surgery and before defining the type of surgery they're going to require, I want to talk about the aims of surgery for a minute and I want us to agree on the aims of surgery.

So basically, when we take these patients into surgery, the aims of the surgery are number one to protect the cornea from further trauma. We want to promote healing by bringing blood vessels and lymph vessels into the lesion because if you look here, there are hardly any blood vessels in these two patients. This one has some blood vessels but they're very Far away from the ulcer.

It's gonna take them several more days to reach the ulcer. So we wanna bring them immediately into the ulcerated area and as I mentioned a couple of times, we're creating a very deep defect, we want to fill it in. Now, traditionally, people have developed several I should say surgical procedures to deal with these deep ulcers.

However, I should say that many of them, some of them are actually contraindicated and are being misused by people. Many people tend to, treat these patients with tarsories or with third eyelid flaps. These are misuses, the, these are procedures that shouldn't be used on these patients.

We should only be doing conjuncti flaps and let me explain my position and why I say that they soy and third eyelid flaps, even though they're often used or misused in cases such as this one. So yes, people often do torso feet, torsoy, what we do is shown here in this picture and in this diagram here. Basically, we suture the eyelids to one another.

So if I look back at the aims of my surgery, obviously when I've sutured the eyelids to one another, the cornea is well protected. However, this does nothing to promote healing because I've not brought in any blood vessels onto the lesion. I've just covered the lesion with the eyelids.

I haven't brought any lymph vessels into it. I haven't filled in the defect. There is still a defect in the cornea that remains unfilled.

Furthermore, if we did tsurphy, it is very difficult to provide topical treatment. Some people may leave a medial opening and have the owner try apply drops to it, but it's very difficult, so you're limited to. Systemic treatment and just as importantly, it's impossible to monitor your patient.

You've closed the eyelids, you don't know what's cooking beneath them. Is it improving or is it deteriorating? There is no way to know.

So really the only indication. For torsoy is following traumatic prolapse. We replaced the globe in the orbit and we close the eyelids until the extraocular muscles and the tissue have healed.

Tyrosoy is not a treatment for a deep ulcer. Neither is a 3rd eyelid flap. A 3rd eyelid flap as shown here is very easy to perform.

I can do one in 5 minutes, as shown here, pass your suture through the upper eyelid from the outside inwards, pass it through the cartilage of the third eyelid, make sure you don't go full thickness and come out again from the inner aspect of the upper eyelid out the skin. Place 2 or 3 sutures, tie them together, and you have a 3rd eyelid. So very easy to perform.

It does afford good protection just like Tsorphy or almost as good as Tsorphy. Topical medications, yeah, they may be applied and because you covered the cornea with a mucous membrane like the third eyelid, some medications will penetrate, not 100% penetration, but some penetration. However, once again, you are not promoting healing because you're not bringing any blood vessels to the lesion.

You haven't filled in the defect and once again, you are unable to monitor the patient. You don't know if the cornea is healing or not. So a third eyelid flat is.

It is not indicated as treatment for corneal ulcers, even though some people do it. The only indications for third eyelid flap as far as we are concerned is if you have paralysis of the trigeminal or the facial nerve, the patient is not blinking either because it's unable to blink. Cranial nerve 7 paralysis or it doesn't feel any foreign bodies so it's blinking less often.

The cornea needs to be protected and it can be protected with a third eyelid flap as shown here until the function of these nerves return. Returns, sorry. And another indication for a third eye flap is this disease shown here, acute bull skeratopathy, a very striking disease in feline eyes, which present, as the name implies, very acutely with a bulluss like a blister on the cornea.

It almost looks like a corneal perforation in the Irish. Coming out, but if you look carefully, the iris is not coming out. The rest of the cornea is very quiet.

The eyes calm. There is no UVI, there is no parotitis. There is just this huge bulge that appears on the corneal surface.

It's very cute. It wasn't there in the morning when the owners went to work. They came back and they find their cat with this huge blister, which can obviously perforate and cause corneal perforation and The treatment of choice for this one is also 3rd eyelid flap.

You cover it with a 3rd eyelid for 2 or 3 weeks. It acts like a pressure bandage. Here is the same cat 3 weeks after applying the 3rd eyelid flap, the pressure bandage worked, the blister is gone.

So these two situations are. Paralysis of cranial nerves 5 or 7 and acutebular sectopathy are good indications for third eyelid flap, but corneal ulcers are not to be treated with a con with a third eyelid flap. Corneal ulcers, when needed, are treated with a conjunctival flap as shown here cause this conjunctive flap fulfils all of the goals and aims that I set out initial.

You feel the defect with conjunctiva because eventually the conjunctive tissue will be incorporated into the cornea. You are bringing blood vessels and lymph vessels directly onto the lesion. Look how well vascularized the flap is.

You didn't cover the eyes so you can watch it, you can monitor it, you can see whether the cornea is deteriorating or not. You can see, look for signs of secondary UVITs and you can apply topical medication according to what you are seeing. The only problem here, as I said earlier, it is difficult to do, it does require training, instrumentation and fine sutures.

Conjunctiva flap is shown in the diagram here. We have different types of flaps. So what's shown here is an advancement flap, maybe the easiest one to do.

We are incising the conjunta with our scissors here, undermining. It separating it. We've formed a flap here and we are advancing it to cover the lesion, suturing it in place, as I said, with 8 or 90, 100 absorbable sutures.

So we have advanced the flap, . As shown here also, that's the same one. We can do a pedicle flap by cutting this conjunctiva and rotating a pedicle to cover the lesion or a bridge flap in cases of a large ulcer cover bridging the entire cornea from top to bottom.

So this is what they look like in Diagrams and here is what they actually look like. Here is in the advancement flap that I've shown. Here is a pedicle flap, B, and here is a bridge flap, C, and you can see the fine suture material that is being used to suture these flaps to the cornea.

At this point, I usually get asked by people, well, how deep are your sutures. So here is your answer. We try to place the sutures at 80 to 90% depth as shown here.

If they are too superficial, you'll get a position of the super. Official cornea, but you won't have good acquisition of the deeper layers of the cornea and you'll have this gap here. So you want to avoid this by making your sutures too superficial.

However, you don't want them penetrating the cornea, you don't want them to be full thickness cause then you have a weak. Going through the cornea, it will allow contaminants to enter the interior chamber. It will allow leakage of aqueous from the interior chamber out and obviously you have a foreign body in the form of your suture material in the interior chamber.

So this is the ideal depth, 80 to 90%. And as shown here, this depth will also determine how far apart your sutures are because this height equals this width. So again we are talking 80 to 90% of the 0.5 millimetre or the 500 microns.

We place our flap as shown here, we do it, we treat the eye, we wait for for it to heal and then after 8. 6 to 8 weeks I should say, you have the option of cutting it off, cutting off its blood supply, trimming the blood supply I should say, as shown here. When I sutured the flap, I suture it around the lesion, but this part of the pedicle remains unsutured, so this part of the pedicle is not adhered to the cornea.

There are just two anchoring sutures here, lots of sutures here and nothing here, so I can come by 6 weeks later, cut it off, separate it from its blood supply, leave a small stump. In the cornea over the lesion and because this stump is now ischemic, it will resolve with time. Obviously, the cornea will never be as transparent as it used to be.

There will be a scar, but hopefully it will be minimal. However, I should say when showing this. Slides that sometimes in certain situations we may decide not to cut off the blood supply.

We want the flap to remain vital for a long time and some surgeons, in fact, may not remove it at all or may not trim it at all. Here is a couple of more pictures showing you the procedure. So here is a deep and contaminated ulcer in the horse.

You can see again the contamination, the abscess, the mushy appearance. You can see that the blood vessels are very far away. We don't want to wait for these blood vessels to grow in, so we place our flap.

Unfortunately, as you can see, there is a bit of pigment on the flap here, lots of blood vessels. I'm very happy. I'm less happy with this pigment cause a couple of months later this is what it looks like.

Yes, we can, we definitely saved the eye, compare this to that contaminated cornea, ha cornea, severe uveitis, the eyes calm. The eye has been saved. However, there is significant scarring and pigmentation, so we've saved the eye, but results could be better as far as transparency goes.

Which brings me to a couple of variations we can play on conjunctival flaps. One is a corneal conjunctival transposition. And that's shown here, and I'll show it in the next slide, but basically what we are doing, we had a central lesion here.

We removed. We covered it with this cornea which laid here, so we transposed this cornea over the lesion and we transpose conjunctiva to cover the new ulcer that we've created. So the central cornea has been covered by peripheral cornea and therefore this improves the long term transparency of central lesions.

Let me take you through it on the diagram. So here is My lesion that I want to cover, you can see that the lesion is right over the pupil. So if I'm going to have scars here, they are going to be severe or dramatic effects, consequences for transparency.

I don't want that. Therefore, I make two incisions in the peripheral cornea. Here, I undermine the cornea.

I've undermined it so the peripheral cornea is free. I undermine the conjunctiva that's adjacent to this cornea. I cut it at the limbus and then I transpose this entire block of tissue from here to here.

So now this peripheral cornea is covering the central lesion, the conjunctiva is covering the defect I created in the peripheral. Cornea and the result is a transparent flap covering the central lesion. Here are two examples.

You can see again the sutures of suturing the peripheral cornea over the central lesion and here is the. In Taiba that has been transposed to feel the defect created when this cornea was transposed over the centre and another picture showing long-term results. Look at how wonderful the transparency of the central cornea is and that's because we've covered it with a peripheral cornea.

So this is one option of maintaining transparency or improving long-term transparency. Another option I should mention is biological scaffolding. Nowadays you can go online and buy lots of biological material, be it amnion, collagen, extracellular bladder, muco, small intestinal muco, and this tissue, can be Placed on the lesion alone as you'll see a minute or underneath a conjunctival flap.

And the reason we place this tissue is because we are using tissue like mucosa or amnion, it really serves as a biological scaffold. It allows or enables the ingrowth of vessels and fibroblasts. It promotes ingrowth of vessels and fibroblasts.

So it really allows for much quicker healing and gives the final outcome greater strength and as it says here, sometimes we will place it beneath a conjunctival flap in cases where we want to promote faster healing or sometimes it can be placed alone as you can see in these pictures. Here is a study looking at 82 cases of dogs and cats where only biological scaffolding was placed. Here is one case from this paper.

You can see a huge perforation due to a melting cornea, huge piece of the iris is coming out. The defect is covered with this biological scaffolding material. This is what the immediate postoperative result looks like and this is the final outcome a few years later.

It's not as transparent as a corneal conjunctival transposition, but it's better than a conjunctival flap and again when you compare this eye to this eye, the owner should definitely be happy. One more variation of the topic of flaps comes up when we have cases of corneal perforation and an Irish prolapse, and here are two pictures of, oops, sorry, two pictures of an Irish prolapse and I know that some people are telling themselves, gee whiz, that doesn't look like an Irish. I mean the colour is totally wrong and you guys are right, it doesn't look like an Irish, and that's because Immediately after the prolapse, it gets very quickly covered with fibrine because the iris is very irritable, it is very easily inflamed, it gets covered with fibrin and therefore it gets this tan coloured.

You can't really see the details of the iris. But anytime you see, as it says here, bulge on the corneal surface surrounded by edoema in case this tan colour, you are probably looking. At an iris.

So what, what do we do with these cases? Well, we have a hole and here is another iris. You can also see some bleeding in it.

We can see some pigment. Obviously, we have a hole and we need to seal this hole so we can seal it either with a conjunctival flap as I described earlier, or with the biological scaffolding that I showed you earlier. The only question to ask at this stage is what do I do with this iris that's protruding.

Do I push it back into the interior chamber or do I amputate it? And here we basically take a very good look at it and try to decide whether it's contaminated or not. This one is obviously contaminated.

It's gonna come out. This one looks fresh. It may be pushed in.

This 1 may be amputated. Basically we say anything over 6 to 8 hours, we would want to amputate. So, and then after amputating we set it up with a flap and the postoperative treatment for all of these cases be them conjunctiber flaps, scaffolding, or amputation of the iris will consist of lots of topical and systemic antibiotics, systemic anti-inflam Inflammatory, consider atropine though you do want to measure baseline suer tear test, probably in the non-operated eye just to get an indication whether or not you can give the atrophy.

And please, please don't forget your Elizabethan collar. Again, the cornea is only 0.5 millimetre thick to begin with.

Now you're talking about far less. You want an Elizabethan collar and one that will really prevent the animal from grabbing its eye. So you don't want this type of colour which is decorative.

You want an Elizabethan colour or something I prefer is this one, because you know that owners would frequently complain that with this. Collar, the dog is unable to eat or drink. With this one, the mouth is not impeded and it has free access.

Or this is one more case where we may do short term temporary torsoy, not a full torsoy, but just one suture. We want to watch the cornea from the both sides. We want the owner to apply drops, but maybe short term torsoy just to protect our work.

Right. Moving on to other procedures, sometimes patients present with corneal laceration, and here are a couple of pictures. Here is a lacerated cornea and here are two corneas that have been sutured following laceration and as it says here following the sturing, if you have a tight seal, you want to reinflate the globe and that's why we have bubbles here, small air bubbles.

You seal it up and then you enter with a needle in the limbus in this location and just inject a bit of saline or even some air into the interior chamber to reinflate the globe. However, as you can, oops sorry, as you can see in this picture, and also in this picture, there is an obvious laceration here, but you have to ask yourself, geez, how far back does it extend because it seems to involve the conjunctiva, the sclera, and indeed. As you can see here, they often go far beyond the limbus into the more posterior segments of the eye.

So sometimes when you're seeing the lacerated cornea, it's really just the tip of the iceberg and the laceration goes further back, . So if you have high femma or subconjunctival haemorrhage, you may suspect that the iris or the UVR or the ciliary body have been damaged, have been lacerated, conjunctival swelling is another indication. So you may consider an ultrasound in these cases and if you see this type of picture with or ocular contents in the retro bulbar space, I guess, this patient should be nucleated rather than referred for a repair of corneal laceration.

One more trauma that's to be considered in these patients that present with these corneal lacerations is not only trauma to the posterior sclera, it, you also have to consider the possibility of trauma to the lens as shown here. You can see that Cat claw penetrated the cornea here at the limbus, that's this opacity shown in yellow, but it also penetrated the lens. This lesion shown with a green arrow.

That's why one is in focus and the other is not. So the cat claw penetrated both the cornea and the lens, and this represents danger number one. One, it can cause UVIs whenever we have rupture of the lens capsule, we can get lens induced UVITs and even if you don't get UVITs, you can get septic implantation in the lens.

After all, cat claw is not a sterile thing even though it's licking its paws so often and you will get a Embed embedded bacteria in the lens and a few weeks or months down the road, all of a sudden you will have endothalmitis, you'll have an abscess in the lens, you will lose the eye due to severe infection. I just had one of these cases blow up in my face a few weeks ago. Not a pretty sight.

So keep it in mind, in cases of corneal laceration. Another procedure I want to discuss briefly is penetrating keratoplasty or corneal transplantation. When do we do corneal transplantation?

Well, we could consider it if we have a huge perforation such as the one that's shown here, a huge Abscess and we've already seen pictures of huge abscesses in previous slides or this picture here endothelial dystrophy, which is an inherited disease in several dog breeds whereby the endothelium stops functioning and we get progressive corneal edoema that's totally Non-responsive to treatment. You can try hypermotic saline it probably doesn't work. You can try other alternative therapies, but some of these patients may benefit from, penetrating keratoplasty or corneal transplantation.

The graft that we use for implantation may be fresh and fresh is preferable if you happen to have a dog that, died a few hours ago in the emergency and the owner is willing to donate the cornea. If not, you can use fro we can use frozen corneas that we keep in the freezer and they can be maintained for years and years. The graph may be from the same species or it can be from other species.

So again, it's very easy to maintain in a freezer a collection of frozen corneas, collected from pigs in slaughterhouse and fold them when needed, and here is a series of pictures from my colleagues in Barcelona showing a huge perforation that was treated by corneal transplantation. Here is the transplanted cornea. You can see how clear it is cause it's cornea immediately after surgery and you can see how the transparency is maintained 3 years later.

So this is definitely a very nice alternative for these patients. Now I promised you that at the end, I will discuss a couple of procedures that you can perform in your own clinic. One of them is glue, tissue adhesive.

Excuse me, which may be used to fill in very deep defects. We use them in dogs, in elderly patients that have very deep ulcers, and the dog cannot be anaesthetized because it's an anaesthetic risk due to its age. This defect can be filled in with Tissue adhesive glue.

This is what the plug would look like, and as the cornea heals beneath the plug and regenerates beneath the plug, eventually the plug will fall out. The way we apply it is we briefly anaesthetize the patient and you thoroughly dry the cornea. For this reason, I maintain a hair dryer in my clinic.

You can't see me on the webinars, so you can't see that my hair is very short. I don't need the hair dryer, but I do keep one on clinic, not for myself, but to dry the cornea of these patients, dry them very. Thoroughly and then place a very thin coat of glue using an insulin syringe over the ulcer bed and surrounding dormi normal cornea and as I said, within 1 or 2 or 3 weeks it will be extruded as the corneal collagen and epithelium are regenerated, but it does give you short term protection.

As it says here, you don't want to use it when the cornea is infected or in cases of melting ulcers. We don't want to use it in these metal ces cause the biological reaction of this adhesive, generates heat, so they will perforate, but in deep ulcers, for example, as a result of a cat claw, that may be the way to go, especially if the patient cannot be anaesthetized. And finally, I want to discuss this entity.

We mentioned it at the end of my talk last week, the so-called Boxer ulcer. I elected to talk about it this week because they are not treated really surgically, but they're not treated medically either. They do need some kind of procedure, some kind of intervention.

So that's why they are part of this week's talk, the so-called Boxer ulcer or recurrent superficial ulcer, indolent ulcer, chronic superficial chronic corneal epithelial defect. You can see that all of these names are really synonyms, to describe the presentation that you are seeing here. We're talking about a superficial defect.

And it's recurrent chronic or not healing, and it is not healing because there is a defect in the basement membrane of the epithelium and the hemismosomes that enable adhesions between the stroma and the epithelium and therefore we get a recurrent superficial ulcer that is non-responsive to treatment. And the telltale mark for the clinical sign for these ulcers, besides the fact that it's recurrent and it's non-responsive to treatment, is this epithelial lip that you are seeing in both, both of these pictures. This epithelial lip is what you saw earlier histologically and because epithelium is just laying here over the stroma but it's not adhered to the stroma, if you put A drop of fluorescine here, it can.

I enter beneath the epithelium, make its way between the epithelium and the stroma, which explains this picture here. You're seeing the edge of the ulcer here and you can see that the fluorescin penetrated underneath the epithelial lip, same with the corneal edoema that's penetrating between the superficial epithelium and the stroma because there is no adherence in this region. We can confirm this diagnosis, so we expect it based on the history and on the clinical presentation and then we can confirm it by taking a swab and simply debriding this loose epithelium and if it debrides while you are looking into the indolent ulcer or the so-called scad.

Or Boxer ulcer because this is really pathognomonic for these types of ulcers. Take any type of other ulcers that I've shown you earlier, deep ulcers, contaminated ulcers, whatever, you will have a mass in the lesion, but the surrounding epithelium will be adhered to the stroma, not here. This can be debrided as shown here.

So we debride it with a swab to confirm our diagnosis and sometimes just applying topical antibiotics and heparin sulphate may allow resolution and here is heparin sulphate from our sponsors. So thank you again TDM. However, frequently, as I said, they do require intervention.

So sometimes I would dip my swab in diluted polyddy, pod iodine, and I would get what's called chemical depriment, chemical cory of the basement membrane and the hemismosomes, and this will allow healing. However, often that's not enough and we have to physically remove the aberrant tissue. In former days, we used to do it with a needle, scratching the corneal surface with the so-called multi-grid keratectomy, keraotomy, sorry, or multi-punctickeraotomy.

You really are playing tic tac toe with the needle on the corneal surface. I'd love to meet the The person who thought it or thought of it initially, but it worked great in dogs as it says here, please don't ever, ever do it in cats cause you're guaranteed to end up with a corneal sequest. This is something you want to do only in dogs, but nowadays we've moved from these needles into the algar brush or diamond bird debridement, this instrument here.

A rotating head that's covered with diamond dust, scratching the corneal surface for 45 to 60 seconds, and that would remove the aberrant tissue and expose trauma to which the epithelium can adhere. Here. So this is definitely a procedure that you can't perform in your clinic.

Instrumentation is not cheap, doesn't require anaesthesia, yeah, as shown here, we often do it on alert patients and it's a wonderful treatment for boxer ulcers. So, this brings this talk to an end. I thank you for your attention.

Thank you, you, and I thank TBN again for their sponsorship and I'll be glad to take questions. Ron, thank you so much for that. And as your picture so aptly shows thunderous applause, I'm sure if we were in an auditorium, you would be getting a really substantial round of applause now.

That you absolutely brilliant. Once again, folks, a huge big thank you to TM, our sponsors. They, they have made it possible for us to bring you this webinar tonight and, the series on ophthalmology.

So, let's support those that support us. Dawn has just popped into the, chat box, that link for the video. Unfortunately, there will not be enough time to watch it tonight.

But, if you copy those links and go back and watch them, they are great videos, and, they, they really are worth watching. Ron, couple of questions came through. Jill asked, when you were talking about the flaps that you were doing, the conjunctival flaps.

What suturing patterns are you using for your transpositions? OK. Let me go back here.

Basically simply interrupted will often do. OK, so here is, OK, there are several social patterns. This is what we call the X pattern, which gives me greater strength, but it is more time consuming.

. Let me go back a bit more often. Here, thank you. Often, as you can see here, we would do just simple interrupted as shown here or even more frequently, what I would do is place 4 simple interrupted cardinal sutures in the four corners of the flap, here, here, here and here and then fill in with continuous .

Suture pattern in between these 4 cardinal sutures. So forcing drop it filling in with continuous and then don't forget 2 anchoring sutures at the base of the flap. These don't penetrate the cornea.

These actually penetrate the sclera in order to give you great strength and to prevent retraction of the flap. Thank you for your question, Jill. Jill has just popped another question through and she said, are you using double-ended su suture waged?

Yes, basically, With this fine needle, fine suture material, the pack comes with two needles. There is a needle at each end of the suture. You cut it in the middle and you are left with two needles, each of them having half length of suture material.

And that's because these are such fine needles. They do get blunt as you are placing the sutures on the cornea. So you have two needles, so you can change when the, the needle becomes blunt.

Excellent. We've got another question that's come through. What would be the indications of a 360 degree corneal flap graft?

OK, a 360 degree, sorry, conjuncti flap, could you repeat the question? Yeah, it says, 360 degree corneal flap graft. I think, that what they meant is a 360 degree con conjunctival flap, which would be similar to this one.

I'm sorry I don't have a picture of it. Basically we take Hey, . We dissect, actually I should show it here, it'd be better here.

So I would do a 180 degree incision here. Do an advancement flap from the dorsal conjunctiva covering the dorsal half of the cornea and then repeat again from the bottom, incising the ventralimbus and advancing the ventral conjunctiva and suture the two of them together. The only indication for that really are very, very huge ulcers.

So you really need to cover the entire cornea. As I said, we usually prefer biological scaffolding or maybe corneal transposition, instead of that. However, and I'm thinking aloud as I'm talking, maybe this would be something that you could actually Do in your clinic because you are not having to actually suture the two halves of the flap to the cornea, you are just suturing them to each other, placing a couple of cardio sutures here and maybe you can get away with covering the cornea this way.

Excellent, excellent. Ron, that's been absolutely fascinating and it's, it's one of those topics where you, you look at it and you think, oh yes, I'd like to be doing that sort of surgery. And then you realise how long it takes to become as good as what you obviously are in doing these procedures.

But it is something which is very, very interesting to me anyway. One other question that we have, and that's about the use of contact lenses. Oh, yes.

What's the question? So, instead of using glue in those ulcers, could you use a contact lens? Basically, a contact lens keeps the cornea comfortable.

It definitely decreases the amount of pain. Excuse me, and, that is a very important indication. It also protects the cornea from further trauma, however, it doesn't fill in the defect, so it's not something I would use in the very deep defect that I showed you where we place the drop of glue in.

We would, we could use, so this is a very deep defect. I don't think you should cover it with a contact lens. Contact lens is are indicated, for example, after the superficialorectomy that I've shown you or after the boxer ulcers that I've shown you and after you perform your dam bi depridement, superficial lesions where you want to protect the cornea and many to increase patient comfort.

Excellent, excellent. Ron, that was absolutely fascinating and once again, thank you for your time tonight and thank you for sharing your knowledge with us you very much, Bruce. And maybe I should just mention that next week's seminar is devoted to cats.

We'll be talking all about feline keratiti and conjunctivitis. Basically, we'll be talking about herpes, a very, very frustrating disease. Worldwide, distribution.

We have herpes everywhere, lots of patients coming to our clinic, and that's what we'll be talking about next week. Excellent, excellent. That's, tell your friends, that's gonna be a good one because I think we've, we've all been frustrated with those cases, regardless of who we are, where we are, or how long we've been in practise.

So, That's a, a, a really good topic next week. Ron, thank you so much again tonight and to Dawn, my controller in the background, thank you for all your help and for all of you for attending tonight. Thank you very much.

From myself, Bruce Stevenson. It's good night until next time. Thank you.

Good night.