Thank you. So this is going to be a, a pretty practical presentation. So what it is not going to be is a, a presentation that covers, complicated graphs and IC 50s and pharmacokinetics and pharmacodynamics.
It's going to be really practical. What do you actually need to keep in your pharmacy, that is not going to expire, . Is not going to mean, I mean, it's expensive to keep drugs on the shelf and you know, you only want to keep the medications that you're going to use.
The, what I'm going to do is for each of the different these these types of medication, I'm going to work through them and I'm at the end, I'm going to tell you, this is what I think you should actually use, or this is what I think you should actually keep in stock. And I'm also going to mention a few medications that I think you should know about so that you can choose to write a prescription. So, in the way that I work is that I keep the, the medications on the shelf that I use really regularly, but then I frequently write prescriptions and, and, and it's partly You know, it's cost effective for the practise, but it's also more cost-effective for the client because it is, I think there's, it's very easy to lose clients because we can, we need to charge more than the big pharmacies do.
So the pharmacies have that economy of scale that allows them to buy in such bulk that they can sell at a much cheaper price. So I'm going to focus on the medications that I think you should keep. And also mention some of the medi the drugs that you might want to consider writing prescriptions for.
So we'll work through both systemic and topical antibiotics, tear stimulants, anti-glaucoma medications, and anti-inflammatories. And then at the end, if there's time, there are some questions that we can work through just as sort of a a way to reinforce the discussions that we've had. So, I'm going to talk about what you should keep on the shelf, how to know when you should actually use them, when not to use them, and then how to use them.
Beginning with antibiotics. Now, in preparing this talk, I actually did a a a a a bit of a review about antibiotics, and I, I really thought that this statement from the WHO, gets it right. When it reminds us that our use of antibiotics, well, our use of medicines, but particularly antibiotics, it should be for that individual patient, it should be required and necessary.
It should be used in the right way, so in the correct dose for the right amount of time, and it should be at the lowest cost. To them and their community, and I think that word cost encompasses a lot of things. So, cost obviously means, you know, money, but it also probably means in terms of risk for things like antibiotic resistance, and, you know, risk for adverse reactions.
Well, and, and the side effects that we can see with with different medications. So I just wanted to to to sort of, and I will mention as well that the WHO has some really great resources about antibiotics, and a lot of them are relevant to the to us as veterinarians, so that's a great place to have a look. So with systemic antibiotics, they absolutely have a place, but I include this slide to remind us that antibiotics are one part of Infection prevention, and hand washing, I mean, gosh, you talk about the WHO website and the information on hand washing is, is, is really very interesting and very compelling.
Decontamination, cleaning, disinfection and sterilisation. So with, if we optimise all of those components, then the need for Systemic antibiotics is really reduced. And I'll talk again, about the specific types of infections that we see, particularly with, corneal ulcers in dogs, and, the antibiotic resistance that seems to be developing.
And that really, reminds us. About why these steps that come first, you know, maybe should be stressed a little bit more. So when this is answering the question, when do I use an antibiotic.
So I would suggest that these are the requirements that we need to first satisfy. The first is, is there a a known bacterial infection? Or is there risk for a significant infection?
So that can include a corneal ulcer that is not yet infected, but where the epithelium is not intact. And if a cornea becomes infected, then that can be associated with a lot of morbidity. So, you know, that, that, that, that would be a time where we would use a topical anaesthetic, sorry, topical antibiotic, but with regard to systemic antibiotics.
Is there the potential for a significant infection? And, and cataract surgery is one of the times when we will use systemic antibiotics, because if an infection develops, then it can have a catastrophic result. Can we use local applications?
So again with the corneal ulcers, this is when we would use a topical antibiotic and not a systemic antibiotic. And will it reach the target. So if we are concerned that there's an infection in the aqueous humer or the vitreous, then, A systemic antibiotic actually doesn't reach very good levels.
So I think we need to think about, you know, what we're using, how we're using them, and why we're using them. So which antibiotic, what dose, and for how long? So what are the indications for systemic antibiotics in ophthalmology?
So I regularly use them when I think there's an orbital infection. And in fact, I don't even require there to be a culture confirming infection when I'm presented with dogs who typically young dogs who have exothalus, painful swelling around the eye. They're often febrile, and ultrasound may or may not show a pocket of fluid.
Oftentimes it actually just shows inflammation of the muscles and soft tissue of the orbit. I will put those dogs on an antibiotic systemically. I think there is enough reason to think that those, conditions are going to be associated with bacterial infection.
The other time I use them often is for blepharitis, and I'll just make a comment though that I do also use dilute betadine, so I'll have owners do cleaning, so I may need systemic antibiotics for blephritis or dermatitis, but not always. I always use systemic antibiotics when there is a corneal or globe perforation or a full thickness laceration. Because I think, you know, again, going back to those checkpoints, we can expect that bacteria will have entered the eye, and the body's immune system is very poor at resolving infection inside the eye.
So I think it's perfectly reasonable to use the systemic antibiotic in those instances, and we can expect that the antibiotic will enter the eye through the uveal tract. Again, I use them for intraocular surgery, which is probably not particularly relevant for those non-ophthalmologists in the group. But again, we justify that because of the, the likelihood of a catastrophic result should an infection develop.
I think it's reasonable to use antibiotics for surgery when it takes longer than 90 minutes. I've written Doxycycline for indolent ulcers as a question mark. Look, to be honest, I don't have a particularly strong feeling about it.
I know a lot of people use doxycycline. I tend not to, not so much because I think it's a terrible idea, but more Because I find that the owners, when I see them, are pretty overwhelmed with the number of medications that they're using. And I think that I have some better methods for treating indolent ulcers, and the doxycycline just ends up being potentially a little bit too involved for owners, and, and also, you know, I do like to make sure I'm using antibiotics appropriately.
But there is absolutely precedent and good justification that doxycycline can be helpful. So, if you, if you have an owner who wants to be doing everything, then feel free. So, some images that I hope we would all agree are probably pretty reasonable times to use an antibiotics, so the image on the left, we can see the left eye of this dog with a, lot of swelling of the eyelids, but also, some swelling of the third eyelid, and you can see that there is exothalus, .
And this dog did have a, an orbital cellulitis. So using an antibiotic is reasonable. On the right, we can see that there is a corneal perforation, so some, fibrin, in the centre of that ulcer, and you can see the anterior chain being very shallow with the iris protruding forward.
So this is going to a case that needs Surgery to address the cornea, but would benefit from systemic antibiotics due to the risk for infection entering into the eye. So when not to use systemic antibiotics, so I would argue that there's no reason to use systemic antibiotics when you have a corneal ulcer alone. So if you do not have intraocular infection, when you only have uveitis and there is no indication for infection, when you're doing an extraocular surgery and it's less than 90 minutes, so if you Use, if you say you're removing an eyelid tumour from an older dog, we know they get a lot of, mybomian gland adenomman's tumours, and so we're frequently removing tumours from them.
Now, it's using Perioperative antibiotics is a little bit, a little bit different, but ongoing systemic antibiotics, I don't think that we can justify it. Periocular tear staining, I would argue, is never an indication for systemic antibiotics and you will. Find that if you have owners coming in and telling you that they're using a supplement into the dog's water, more often than not, that is a tetracycline that they're putting in water, and I think that's a terribly inappropriate use of antibiotics.
So, we've talked about when to use antibiotics, and now we're moving on to, yeah, so which ones? What, what, what should I actually have in the pharmacy? So I do feel that there's an indication for using amoxicillin clabuanic acid, so it covers gramme positives and gramme negatives and ants.
It is not targeted, so it is going to, Kill both your friendly and unfriendly bacteria. And if you can use a more targeted antibiotic, then you should, but I do find that this is a good antibiotic to use in cases such as, orbital abscesses or cellulitis. I use it at a high dose, though.
I use it at At least 15 up to 20 milligrammes per kilogramme twice a day. And I use it for 3 days minimum. So cataract surgery, I use it for 3 days.
If I'm dealing with an orbital abscess, then I may need to use it for quite a long time. So I think again, you know, there isn't a one size fits all, we need to think about our patients. But treating for the, The shortest appropriate time so there there isn't a reason to continue therapy when it's no longer indicated.
So, the other antibiotic that I would suggest you should keep in your pharmacy is acephalosporin. So these are better for cockey, than they are for gramme negative bacili, but they still have a reasonably broad spectrum, but because they're more targeted, they're friendlier to the chemists. Some non-pathogens.
They're a really good choice for periocular dermatitis, and I also use them for pre or perioperative antimicrobial, coverage. So, there's quite a bit, available, both in the human and the veterinary field about, how to use these, antibiotics for, peri-surgical coverage. And one of the things that's really important is that it needs to be given before the incision is made.
And it can be given up to 120 minutes before the incision is made. So, that, yeah, just making sure that you speak to the people anaesthetizing your patients and make sure that that antibiotic, if you're going to use it, make sure it's given before you make an incision. I spoke in the previous, presentation about ophthalmic emergencies about formulating cefazolin into an ophthalmic preparation, and I think it's a great drug to use topically, and we'll talk a little bit more about that when we move on to discuss topical antibiotics.
You may choose to keep doxycycline, certainly, you know, a great drug for cats, so you'll probably have it for that anyway. And, you know, again, the veterinary formulation, at least in Australia, is a little bit more friendly when it comes to risk for esophageal strictures. So it's probably a good one to keep, but if you're really trying to be as minimalist as possible, you might be able to, to do without it.
So, now, moving on to topical antibiotics, we've talked about the systemic antibiotics, and now we're moving on to the topical antibiotics. So which ones should I actually keep and when should I use them? So the indications are, anytime the corneal epithelium is disrupted, and we know the cornea does not have a blood supply, it's not very good at fighting its own, battles, so, if, if we are concerned.
That the normal defence mechanism of the cornea, mostly an intact epithelium, is not intact, then use a topical. If you do surgery, either inside the eye or on the eyelids, it's reasonable to use a topical antibiotic. And I, I guess, you know, in terms of bacterial overgrowth, so I do see a lot of patients who come in with conjunctivitis, a lot of dogs who come in with conjunctivitis.
And they've often been treated with a lot of different antibiotics. And typically the owners will report that they have tried lots of different antibiotics, sometimes they've even had a culture, and that the symptoms improve with antibiotics, but then they come back when they stop the antibiotics. And I guess in those situations, I just think it's probably more appropriate to try to see whether there's an underlying reason that the for the conjunctivitis and particularly chic conjunctivitis seeko or dry eye, I think a lot of cases, canine cases of conjunctivitis that are being treated with topical antibiotics probably actually have dry eye.
And better to address that. So contraindications, it's never, you know, it's really going to cause a problem to use one. It's more that there are inappropriate uses of topical antibiotics.
Now some animals will have an allergy or a hypersensitivity, and, and you know, that's, that's a little bit of a different situation. So if you know that they are sensitive to it, then you know that would be a contraindication. I would also make the comment that using, Antibiotics as lubricant, so oftentimes, I was involved in a study looking at the reasons people used antibiotics in topical antibiotic ointment in cats, and in that particular study we were looking at an antibiotic that was associated with anaphylaxis.
And interestingly, one of the most common reasons that people use that antibiotic was for lubrication during anaesthesia. And I would just say that, you know, if you can use a lubricant alone, do that rather than using an antibiotic. I would classify that as an inappropriate way to use an antibiotic.
And in those cats, you know, the fact that it then was associated with anaphylaxis, was all the more reason, you know, not to use it. So, conjunctivitis in dogs is going to be more likely to be from KCS, an irritant, or confirmation. I also see a lot of situations where antibiotics are high, big gun antibiotics are used when they're not indicated.
So an indolent type ulcer, those boxes that have ulcers that go on for weeks or months, and they're not deep, they don't have cellular infiltrate, they don't have any other indicators of infection, yet the the treatment has been to change antibiotics. And if infection is not the problem, then antibiotics are not the answer. So escalating your antibiotics in those situations is not appropriate and what it is doing is changing the bacterial flora in the eye, .
To make it more likely that if, if you do develop an infection, it's more likely to be resistant. So, in an indolent type ulcer or a superficial ulcer, just stick with the, you know, the routine broad-spectrum antibiotics, . So cytology is really helpful for aiding your selection of antibiotics.
So do use local anaesthetic, and then using a dry cotton swab, or you know something, I'll sometimes use a little spatula, whatever your technique is fine, you do it carefully and don't do it if you're worried that the eye rupture, but and then aerobic, culture and sensitivity. There are situations where anaerobes have been cultured from, corneal ulcers, but it's not very common. And then thinking about, uncomplicated versus complicated ulcers, which we talked a little bit about in the previous, Talk, and that will answering that question, is this an uncomplicated or complicated ulcer and therefore, what is the most appropriate treatment.
So, here we, I'm comparing a, an indolent type ulcer. So, you can see the superficial ulcer on the left-hand side there's some fluoresce retention, there's some redness of the conjunctiva, but there is no stromal infiltrate, no stromal loss, no signs of infection, as compared with the image on the right, where there is, you can see Corneal blood vessels, which tells you this has been a more chronic ulcer. You can see they're really nasty cellular infiltrate that light discoloration of the cornea.
And the fact that the cornea and probably the anterior chamber is very hazy, so that would certainly be an eye that I would be culturing, and I would absolutely be using a, you know, a, a more potent antibiotic, based on my cytology results and while awaiting my, aerobic culture and sensitivity. So, we talked a little bit about this in the previous talk, but uncomplicated ulcers, are those that, satisfy these criteria, so they should be superficial, they should be acute, there should be no stromal loss or anterior chamber reaction, using a prophylactic antibiotic. So this is an antibiotic to prevent.
Infection, not to treat them. So an antibiotic, just a, you know, a broad spectrum, we'll move on to that in a moment. Atropine as needed, and I typically use an oral non-steroidal anti-inflammatory and a hard plastic E-collar, as I mentioned before, in ophthalmology, there's never a good reason to use a soft collar.
If you need a collar, you need a hard plastic collar. If it isn't infected and therefore a complicated ulcer, and you see cockeye, then it is probably strep or staph. You can't tell the difference just by looking at them, because the difference between them is, going back to microbiology is whether they're catalysed negative or positive, which is not something that most of us are going to be doing in the clinic, .
So we pretty much just have to say, OK, well, it's probably a strep or a staph. Now there are geographic differences in fluoroquinolone sensitivity to streptococcus, and, and that's important, when it comes to your selection, so I will typically, if I see cockeye, I'll use chlorrophenacol and or efazolin, depending on what they've already been treated with. If they come in and they're already on chlorphentacol, then I'll often put them onto efazo.
They rarely come in on cefazolin, which is fortunate because it means I've got somewhere to move, and, because it needs to be compounded, and in your handout, I have provided the reference, sorry, the recipe to make up the cefazolin into an eye drop preparation. You apply the drops really frequently if you think the ulcer is infected. So, every 2 to 6 hours.
You may also use serum, I would suggest using atropine, and NSAID and E. Cola, and you may need surgery. So cytology, cockey, and this is this, this paper that my colleague, prepared and I was involved in, looking at, the situation in Australia, with infected ulcers where strep was, streptococcus species were cultured, and we found that they were, ubiquitously resistant to fluoroquinolones.
So fluoroquinolones are the ofloxacin and ciprofloxacin, whereas in the United States, if it is The streptococcus, then it's very likely to be susceptible to a fluoroquinolone. So just a really interesting difference in geography, and I've included the references, where the, results came from, and then the result, specifically with regard to streptococcus. These papers looked at, overall antibiotic resistance, but this is just picking out what I thought was most, important to, to, to us in practise about streptococcus.
So if you perform cytology and you see rod-shaped bacteria, then it's probably going to be a pseudomonas or an E. Coli. They are, the good news is that they are usually susceptible to fluoroquinoline, so the ciprofloxacin.
And the ofloxacin, regardless of where you are in the world, those drugs usually still work well. However, gentamicin and Tobramycin, there is more variability. I tend not to use gentamicin.
It's quite toxic to the corneal epithelium, so I will tend to use the fluoroquinolone much more often. Again, serum, atropine, a non-steroidal anti-inflammatory, E. Coli, and depending on how they respond to surgery or how much corneal thickness has been lost, they may need surgery.
So, what should you keep on the shelf. I tend to reach for what in Australia is called optoin, which is a combination of chlorrophenacol and polymixin B. And in the United States, I'm aware that chlorphentacol is not available.
You can get it compounded, but generally you're going to, you know, be more likely to reach for a triple antibiotic, so a combination in polemic and bacitracin ground side and. or, or terramycin, which is the oxy tetracycline plus polymixin. So there's a good first-line prophylactic antibiotics.
They're broad spectrum, and they are preserving the, more potent antibiotics for when you really need them. Please, you know, look, I, I see plenty of cats that have been on triple antibiotics, and a lot of them are absolutely fine, but I'd be remiss not to mention that I, I know I personally don't prescribe them, and I was involved in a study that looked at the association between use of those antibiotics and anaphylaxis in cats. They're often not helpful, and given that there is an association, I just prefer to avoid them.
So, that's, that's, that's sort of my, my take on it. I, I, I tend to use, chlorumphenacol, I I think it's a, a better, better choice. So you, I, I, I would suggest having some more potent antibiotics on the shelf, but even, even then, you know, if you have a pharmacy that has good opening hours, you may even be able to avoid keeping these on the shelf, but, you know, it's probably a good idea to have a few bottles handy.
So a second line. Or a more potent or a bigger gun. Some people will describe them antibiotic that's effective against the causative organisms of infected ulcers.
So, cefazolin is a great choice because you probably already have that as an IV preparation, and it's easy to make it up into an eye drop, or chloropanool, which, depending on where you are in the world, is variably available. And then, you know, again, the fluoroquinollines is, is a good thing to have a little, you know, a few bottles of, so the loxacin or the ciprofloxacin, or an aminoglycoside, so something like gentamicin or Tobramycin. I don't think you really need to keep both.
So, you know, cefazolin or chlorophenacol, a fluoroquinolone or an aminoglycoside. Alright, so covering antibiotics, and now moving on to tier stimulants. So, I guess in order to decide, well, what should we use to treat dry eye in dogs, it probably is worth just considering what is the disease process that we're treating.
So the majority of dogs who have dry eye, they have an immune-mediated adenitis or inflammation of their larymal gland. And The reason that we use cyclosporin or tacrolimus is because it provides both targeted treatment of the underlying problem, rather than just symptomatic, management. So it's, it's vastly superior to use cyclosporin or tacrolimus than it is to use a Lubricant.
And, and I think a lot of owners are a little bit confused about this because it's a little bit different in humans. A lot of humans will just use a will just use a lubricating eye drop. But they, it is a bit of a different process.
And also the, you know, obviously our, our canine patients can't be putting eye drops in every 15 minutes, like, like a person would. So cyclosporin or tacrolimus, they share their mechanism of action in being T cell suppressors. They're also anti-inflammatory, and they're also like chromostimulant.
So they're working through a few different mechanisms, and I always mention that to the owners. I tell them the three reasons that we use these drugs, because they're expensive, and the owners would much rather use a lubricant that they can buy over the counter, but it's not going to do nearly as good a job. And I also remind them that the better we can control the underlying disease by stopping the immune system from attacking the gland, the better the long-term prognosis as well, because once you've completely eliminated the gland, you know, it's been completely destroyed by inflammation, then the drugs don't work very well at all.
And this little dog on the right-hand side of the screen, you know, a lot of corneal melanosis and fibrosis, and, that's not going to be reversible, or a lot of that's not going to be reversible, and, you know, we're coming in on this, pretty far down the line. So the indications are a Shermat test that's less than 15 millimetres per minute. Now, I don't always start treating just because of the Shermatier test result, so I would choose to treat or not to treat, depending on the presence of symptoms in conjunction with my Shermatier test.
So redness, that really sticky discharge that owners will, will often, you know, understandably, think looks like there is an infection, and as a, as a parent of little kids who have had conjunctivitis, it sure looks a lot like bacterial conjunctivitis in, in, in people, but in dogs, it's just, you know, it's really quite uncommon to have a bacterial conjunctivitis. So that's sort of really sticky, yucky discharge that you know, I, I can sort of pick up from across the room that it looks like a dry eye discharge, but will often be erroneously treated as infection. There may be keratiti, so either ulcerative or non-ulcerative, so blood vessels, fibrosis, melanosis, or ulcers.
So this image, which is from the UC Davis website, and this shows a much more acute KCS, acute dryer. So we don't have the normal signs of criicity as we did in the, you know, in little white fluffy dog with the terrible melanosis. This is more of an acute onset, and you can just see that it almost looks a A little bit granular.
And people with dry eye describe it as feeling a lot like they've got, sand, you know, that sort of foreign body sensation. So really unpleasant. These, these dogs are often very painful, because of that, gritty sensation when as their eyelids pass over their eye.
So contraindications, and I'm sorry about the font here, the, it's come up a little bit differently on the screen. So contraindications to tear stimulants. Look, I would argue that it's a contraindication to use compounded medication when a commercial product is available.
You know, I know it's a little bit academic, but if we follow Prescribing guidelines. When we prescribe a compounded medication, we are then taking responsibility for that drug, you know, an individual responsibility as opposed to using a commercial product, wherein, there's been rigorous safety and efficacy trials indicating that it's an appropriate, appropriate medication. So I always do use the, use the commercial product first.
And I say that I don't, I will acknowledge I have no financial investment in Optimmune, but I do, I do think it's the right drug to use as the first line treatment for KCS in dogs. I think it is our sort of responsibility to try it first. If it doesn't work, then by all means move on to a compounded product.
I use tear stimulants, even when ulcers are there. Generally, I think that the dryness is more of a problem than the immune suppression might be. And also, I don't believe that T cells have a particularly strong function when it comes to fighting infection and corneal ulcers.
So, I will tend to use, continue to use, cyclosporin or tacrolimus, even when there's an ulcer. Now, I always mention to people, particularly when it comes to tacrolimus, to make sure that they wash their hands or wear gloves, there is an association between tacrolimus and oral tacrolimus and cancer in people, which is also just another reason not to use, not to use it if optimmune, you know, the commercial product might work. So, I would argue that you should keep some Otomy on the shelf, you know, I feel as though you would use it often enough to justify.
I use it twice a day, always, a lot of owners will get a good response, and so they'll then try to taper down to once a day or every second day. Really, it only works for 12 hours. So if you're using it less than that, then there's going to be some adenitis in between times, some damage to the glands.
So I do continue it twice a day. I use it for at least a month, at that dosing, frequency before I move on to a more potent product. So compounded cyclosporin 1 or 2%, though it can be quite irritating, or tacrolimus.
0.02%, and again, those are usually used twice a day, and tacrolimus is more potent and is often you'll get a response to tacrolimus and you have not had a response to. OK, so moving on to the anti-glaucoma medications.
So there are two broad classes of anti-glaucoma medications, the carbonic anhydrase inhibitors and the prostaglandin analogues. I'm not going to speak much about the hypertonics like Manitol or glycerin, because I don't feel that they have a real place in long-term management. Look, I use them from time to time, in order to determine whether an eye has the potential to regain vision.
So we don't expect an eye to be visual when it has a very high pressure. But what we want to know is if we can bring the pressure down, will the eye have vision? And, and that can help us to determine, should we be proceeding with things like glaucoma, shunt surgeries, and, you know, putting, putting in, performing laser surgeries or, you know, these, these big surgeries that, that we might do, we don't want to do them on an eye that isn't going to be visual.
So they can be helpful in lowering intraocular pressure in the short term. But I think we have to bear in mind that they are not good, they're not a good therapy because they cause systemic side effects. So talking about the carbonic anhydrase inhibitors, so dorzolamide, brinzolamide, there's sometimes an added beta blocker, which is Timolol, you know, more often than not, they reduce the production of fluids.
So I think about them as turning down the tap. . They are available in some parts of the world as an oral formulation, but they are more likely to produce side effects of acidosis, so you can see panting and gastrointestinal signs.
In Australia, we don't have access to methazolamide. We do have acetazolamide, but it tends to produce a lot of side effects, so I don't use it. So, the carbohydrase inhibitors.
I use them, they're usually my first line treatment for glaucoma. I use them when the pressure's above normal, or when the pressures are asymmetrical between the two eyes. I use them for primary glaucoma, in the acute instance and also for prophylaxis of the other eye.
So we know that using them. Will delay the onset of glaucoma in the fellow eye. So really important, I think, to talk to their owners about the fact that, sorry, primary glaucoma is a bilateral disease and that using these drugs can help to delay glaucoma.
Not forever, can delay it for a while. Secondary glaucoma. Now the nice thing about carbonic anhydrose inhibitors is they don't cause meiosis and therefore they're safe to use.
If you don't know whether the lens might be luxated or you're not too sure what the cause of the glaucoma is. So for example, you know, if there's uveitis, you can still use these. Using the oral formulations is not going to be a good idea in a dehydrated animal, or a dog that's, you know, also on furosemide for heart disease, or has renal disease or is prone to gastrointestinal uptake, sorry, upset.
I don't use Timolol, which obviously is not a carbonic anhydrase inhibitor, but I mention it because it's often, you know, grouped in with one. In animals who have cardiovascular disease. So the prostaglandin analogues are the Latanoprost, Traviprost, lumi again.
There's lots of different trade names of these. So they increase aqueous outflow, particularly there's those, if you remember back to veterinary school, there's those two ways that fluid leaves the eye conventional and unconventional, and this is particularly helpful for unconventional uoscleral outflow. They cause meiosis.
They, they, they probably do also contribute to some uveitis. I use them again when there is a diagnosis of glaucoma and particularly primary glaucoma and particularly in primary glaucoma that has not responded to or has stopped responding to the carbonic anhydrase inhibitors, often those will work for some time, but then they will stop working. Secondary glaucoma, it really depends on what the cause of the secondary glaucoma is.
So we do not want to use them if there is a known lens fluxation or if there could be a lens fluxation because by causing meiosis, they can make glaucoma much worse and trap the lens in the front of the eye and also contribute to a pupil block glaucoma. If we use them when there's uveitis or inflammation inside the eye, we increase the likelihood of adhesions forming between the iris and the lens, and therefore disruption and disruption to fluid flow by scarring. So not ideal to use when there's uveitis.
So, in terms of what you should keep on hand, I would definitely keep a carbonic anhydrase inhibitor. So I will sometimes use them several times in a short period of time, on an ongoing basis, 3 times a day. Should you keep a prostaglandin analogue as well, you may prefer just to write a script, .
And whether or not you keep an oral cup on a anhydrose inhibitor, that's up to you. I don't, there isn't a reason to use both an oral and a topical. And just a reminder to try to avoid pupil dilation in most cases of glaucoma.
There are some exceptions, but as a rule, we do not want to dilate the pupils, so avoiding things like atropine or trapia. Anything with a red lid. Anti-inflammatories, so you can be a cause and or a result of other eye diseases, so things like ulcers, things like surgery, and they can have significant results, so inflammation, you guys can lead to glaucoma.
Unfortunately, it's a bit tricky because there are quite a few anti-inflammatories on the market, topical ophthalmic anti-inflammatories that really don't penetrate into the cornea or intraocular tissues. So the bad news is that there's lots to choose from. The good news is that I'm going to tell you, I think there's only, you know, you only need to choose one to keep on the shelf.
So, when do we use them? We use them when there is inflammation inside the eye, and there is not a corneal ulcer. So it might be because there's a cataract or there's been trauma, when we've done surgery, .
And you can use an oral and a topical steroid. So both. You can also use an oral steroid at the same time as an oral, sorry, you can use a topical steroid while you're using an oral non-steroidal.
That's not a problem. What people will often ask me whether that's OK. So obviously not combining the two orally, but fine to combine them, a topical with an oral.
So, So this should say contraindications, so uveitis when there is a corneal ulcer, so this is contraindications, I seem to have lost that beginning of that word off the slide, I'll correct that. So in these situations, the only anti-inflammatory that we want to use is an oral NSAID. In fact, we don't even want to use an, an, an oral steroid if we can avoid it, because it will come out in the tears.
So the contraindication to a topical anti-inflammatory is an ulcer. . So, indications for anti-inflammatories is when you have a non-ulcerative keratitis, so things like PAIS, and carefully in cases of feline sinophilic keratiti.
So contraindications to oral steroids, you know, we're probably pretty familiar with these, and contraindications to oral NSAIDs, again, also probably pretty familiar with these, contraindications for anti-inflammatories, when we have a corneal ulcer or when we have either an active or a history of there being feline herpes virus. I'll also mention, please don't use topical non-steroidal anti-inflammatories. You know, they're not something that people will always have on the shelf, but there are topical non-steroidals like diclofenac or flubuprofen, so we'll use those sometimes, but don't use them when there is a corneal ulcer, they're not safe to use, just use an oral.
So, an oral non-steroidal, which you probably already keep in stock for various other reasons, and again, you know, again, prednisolone, which you're going to have on the shelf, in ophthalmology, very few reasons to use beyond an anti-inflammatory dose. And then in terms of a topical steroid, prednisolone acetate or dexamethasone, I would argue those are the only two topical anti-inflammatories that you need, and you don't need both of them. So choosing either prednisolone or dexamethasone, no need for hydrocortisone or any of the other combination formulations that are available.
So, in summary, your ophthalmology pharmacy, this is, are the 10 medications that I think you need, and I have put in bold the medications that are the only ones that you really are going to need to purchase specifically for ocular use. The, the others you're very likely to have for other indications. And the safazol topical, we could probably remove the bulb from that because you'll have the fazol and .
Injectable, more, more likely than not. So, we're going to go straight now. To questions.
So I invite any questions. We'll just see if anybody wants to come up with any questions. We've got those poll questions, .
Yeah, I just wasn't sure if we had time. I think they'll be good. It's always good fun of polls, so if, if you want me to, I can, I, I'll stay on and, and launch them and then go through them and give you the, the scores and then we can see what and maybe we won't do all of them.
You tell me when I've got quite a few so we can, we can see how we go. We'll see when, when . When people are starting to throw things at you, virtually you you've to stop on the, the polls.
So, . We have the first question, which was, I, I think I've just clicked beyond it. It said, what is your next step?
I think this is what you've got up here. Apply fluorocene stain, prescribe a fluoroquinolone, prescribe a topical non-steroidal, submit a swab for aerobic bacterial culture and sensitivity. Is that?
The one we're on, I'm just not sure if they can read the the slide behind that's asking the question. Yeah, go to the next slide then cause that's probably. I can also move that.
It might help. OK, so you examine the dog and you see this. So I'll just read this.
So you've got a 7 year old boxer dog, two weeks of a history of a painful red eye. They have been treated for a week with a triple antibiotic, ointment. It's helped a little, but they're still squinting.
They've never had a problem with their eye before and they're otherwise healthy, so you take a look and you see this. So what do you do next? So we've only got one person voting so far, so let's all have a, a go at it.
Do you either apply some fluorocene stain, do you prescribe a fluoroquinolone, do you prescribe a topical nonsteroidal, or do you submit a swab for aerobic bacterial culture and sensitivity? And we'll just give another couple of seconds as people get used to it, just let's have a couple of more people voting. You can all vote it just to click on the actual poll and and decide what you want to do, so .
Fortune favours the bold, we've got . 86% of people are saying apply a fluorocene stain. I'm very glad to hear that.
12 who said submit a swab for aerobic bacterial culture. And sensitivity. OK, so I, I, I would support the notion of applying fluoresce, .
And you do, and this is what you see. And then the next question. Yeah, which we've got, right, just hold on a second, so I now go to Yeah, polling question 2.
What is your next step? Do you submit a swab for aerobic bacterial culture and sensitivity? Do you diagnose an indolent corneal ulcer and perform a cotton bud deprived or grid keratostomy?
Do you request a full body MRI? Or do you increase triple antibiotic ointment to, every, every 4 hours. And I've launched that poll now so that people can vote.
So submit a swab for culture. Diagnose an indolent ulcer and perform a cotton bud deprivement or grid keratostomy. Do you request a full body MRI or you increase your triple antibiotic ointment to every 4 hours.
How often were we using the ointment before, Alison? I think it was 3 times a day. 3 times a day.
Maybe twice a day. So, we have a bit of a split of opinion. No voting for a, a full body MRI which is.
Increased triple antibiotic ointment to every 4 hours is also not, got anybody scoring it, so. Oh, I'm glad to hear that. Yeah, about 40% saying do a swab, and about 60% saying they just go ahead and do a cotton bud debridement or grid keratotomy.
OK. OK. So the, the, the correct, the correct answer in my opinion is, is, is to go ahead and diagnose an indolent corneal ulcer.
And the reason is that, this, this probably comes down to choosing what is a complicated and an uncomplicated corneal ulcer, and then determining the reason why it's a complicated corneal ulcer. And I would say that this ulcer does not show any signs of Being infected. So there's no stromal loss or change in stromal character, and there's no change in the anterior chamber, so there's no hyperpyon or fibrin.
So I would, together with the signalment being a boxer, be happy to call this an indolent corneal ulcer. There's also some, and it's probably because it's a photograph, so probably in real life, people might have felt differently about this case, but there is some fluorocene. Dissecting underneath nonadherent epithelium.
But the other thing is, is that if you were to apply some topical anaesthetic and rub this with a cotton bud, you'd, you'd pretty quickly get your answer anyway. So even the person who, the people who elected to take the swab, they'd probably find that as the epithelium came off as they were collecting the sample, that might impact their They're thinking that it was an inulin ulcer anyway, so, I don't think either option, you know, is, is, is, is, is bad, and I'm, I'm glad to see that the radiologists might not like that we didn't do an MRI. OK, good.
And I think there is another question there. I've got the, yeah, if you want to go to the, oh right, so, which medication, so I'll just launch it. Which medication, do you prescribe?
A fluoquinolone? Topical non-steroidal and oral non-steroidal. E.g.
Meloxicam or amoxicillin clavulanic acid. And I'll say only one of those is correct. Which one do you would you prescribe in addition to the triple antibiotic you're already using?
Yeah. Give people another couple of seconds just to we'll so we can go through this. Not everybody voting.
It's good when it's, when it's, . Confidential cos even if you get it wrong, nobody needs to know, so feel free to. No, I can't, I can't tell anything, so.
Yeah, I'll I'll shout them out for you, so . We've got a bit of a split. Nobody going for am amoxicillin clavulonates, .
16% are saying go for the floraquinolone. 16% are saying go for the topical. And 68% saying going for the oral non-steroidal.
OK, good. Alright, well, the majority of of of the voters are correct, so the, the best choice, is a, an oral non-steroidal anti-inflammatory satisfying the indication for a a . Using an oral anti-inflammatory when you have a uveitis, you know, a reflex uveitis from keratiti and you would not want to use a topical anti-inflammatory.
So either a steroid or a non-steroidal would be dangerous in this situation, so a poor choice, and there's no need for an oral antibiotic because it's not going to, there isn't an infection and it's not going to reach appropriate concentrations in the cornea anyway. The fluoroquinolone is, I would argue, an unnecessary, escalation in antibiotic. So I actually think that the triple antibiotic that's being used is fine.
There's no indication for infection and therefore, the only reason to use a big gun or a very potent antibiotic like fluoroquinolone is when you actually think there's an infection. Yeah, great. So the correct answer being meloxicam.
There's a good addition. Mhm. That's excellent.
We've got polling 4, do you want to. To do that, is that another case? We've got about another 3 or 4.
Yeah, there are some other cases or if there are general questions, I'm happy to answer those. OK, well, let's let's see if people have got some questions. I know we've got .
We've got Ron who's arrived as well, which is great. So, Shalom Ron. Good morning.
8 o'clock in the morning. Hey there. Listen, thank you so much both of you for for coming on and doing this and obviously this is, we're gonna call this the Boydell symposium, cos of course we lost a dear friend.
In the ophthalmology world, last year, who I used to go and see practise with in Manchester. I did the dermatology. He did the the ophthalmology, it was Pip Boydell, he was a good mate, a very good ophthalmologist, didn't always do things the way that everybody else did them.
So he was a bit of a maverick, but I think that was all part of the charm and. And we need people like that in the profession as well, a great guitarist, world champion kickboxer, and unfortunately died far too young, so, . Thank you everyone for coming on and obviously thank you Ron and Alison for, you know, dedicating this session to him as well.
I really appreciate it and I know a lot of other people, my pleasure, it's an honour and a privilege to beer be associated with him. And I'm hoping that we've got a few questions if if Ron, if you want to . Say anything or or put anything there that would be fine.
But Jamin is saying what is your experience of fusilic acid and or cloxicillin as a topical antibiotic, because these are the only licenced topical products available in the UK. Is that something that you er use at all, Alison, in Australia fusidic acid? So fusidic acid I think is a good first line antibiotic, yeah, so it would be sort of the equivalent to the triple antibiotic that that I've been referring to.
I don't think it's a great, the the studies suggest it's it's it's perhaps not. Great choice for an infected corneal ulcer. And cloxicillin is a fluoroquinolin, and I'm actually just need to have a look.
Do you know off the top of your head, Ron, what what generation fluoroquinolline that is? I'm afraid I do not. Yeah, I'm just having a look.
It's certainly one that we shouldn't be using as a sort of first line anyway, is it really? Well, it actually, I think it's a penicillin, so it's a it's like it's like a oxylab. Yeah.
Yeah, yeah. So I don't think it's available as a topical. Which is the proxacillin in the fusilic acid is our common one in, in, eye drops in the UK, while we wait, if he wants to make a comment, Christopher's just asked another question about when you treat your tachrius for, dry eye, how long is it before you repeat the tier test?
When I use optimmune or when I use tacrolimus, so the same, I wait at least a month. OK. If if the patient had a corneal ulcer, I would recheck the corneal ulcer to ensure that it was not deteriorating, but I would not expect a complete response to the tacrolimus.
For at least, you know, a month. You, you, now that being said, you may see some improvement sooner. I'd say, you know, you may see it in 2 weeks, but I tend to also tell owners that it may take some time, and I, I, I, I hope that that encourages them to continue to use the medication, even if they don't notice an immediate improvement.
So, I, I would, I would give it a month. Brilliant. Christopher is saying cloxicillin is available in Australia.
Obviously we've got a mix of crowds, so whenever we're, we're listening to this, obviously there may be different sort of cascade type things where you can use products in UK but can in Australia or vice versa, but he's saying. Yeah, I can, I can see now that it's that is is is cloxacillin. Used mostly in horses known as optic clocks, so it's obviously, it sounds like that is an eye drop, doesn't it?
Hm, yeah, yeah. And that, they, they, they do include the amoxicillins as, sorry, they do include the penicillins in, in several of the studies, so there is, we do, we do know a bit about the spectrum, and it tends, they tend to be quite good. So that would be a reasonable choice.
But again, if an animal were already being treated with it, I would be more inclined to change to a fluoroquinolone, if the in the signs of infection were progressing. So, . Just a final one, Ellis is saying, you know, what do you think about using fusidic acid twice daily rather than once daily?
I don't use the drug very often. I suppose I would be very, I'd be sort of concerned about using it only once a day because any topical antibiotic is only, it has such a short duration of efficacy. I, I guess I'm just not sure enough about the epithelial toxicity, as to whether it's Sure.
I ideal to use it at that frequency and again I guess if I were wanting to use it more frequently than the label dose, I'd probably be more inclined to change antibiotics rather than use it at a higher frequency. Now that being said, sometimes we can overcome. You know, gel diffusion antibiotic susceptibility by applying things more more frequently to the eye.
But again, I really don't think fusidic acid, I believe it's bacteriostatic, so I probably would change over to a more potent antibiotic if I were concerned about infection. That, that's great. Ron, do you want to put your slides up so that we've got your slides ready and we'll get you going in a minute?
