[00:00:02] Introduction: Welcome to All Cats Considered, a podcast from the Feline Veterinary Medical Association.
Here we interview professionals from across the veterinary world and take deep dives into the latest evidence based research developments, studies and guidelines that improve feline health and well being.
We are the home for veterinary professionals seeking to enhance the care of cats through high standards of practice, continuing education and evidence based medicine. In each episode you'll hear interviews with a variety of experts in our field covering a wide range of topics and the latest developments in feline health. We'll share the key points you need to know to improve your patients care.
Let's dive in and listen to this week's experts.
[00:00:45] Yaiza Gomez Mejias: Natalia Giannakopoulou and Ben Blacklock work at the ophthalmology department at the Royal School of Veterinary Studies in Edinburgh and they have recently published a very helpful guide about fundoscopy in cats in the Journal of Feline Medicine and Surgery. So fundoscopy is such a relevant tool in our routine physical examination, especially in senior cats and those with eye problems. And an ophthalmoscopes are available in most practices, but still some vets may need advice to use them correctly.
So what main tips would would you recommend for them to gain confidence when performing a basic ophthalmologic exam?
[00:01:24] Natalia Giannakopoulou: So yeah, I think I agree with you that thermoscopy definitely can be a bit intimidating for some clinicians even as you said, the ophthalmoscope is widely available.
I think for me my biggest tip would be, which could sound quite basic, but to just pick up the ophthalmoscope and use it as much as possible and, and also not to use it only for cases that have eye problems, but also to examine a lot of normal eyes. And I think clinicians would benefit in many ways by doing this. First of all, they would familiarize themselves with the ophthalmoscope better and they would learn what different settings do on the ophthalmoscope. Let's say, you know, you have the diopter wheel that you can use to focus on different parts of the eye and that can be helpful to know that, but also by examining a lot of normal eyes, because there's a lot of different variations in what a normal sponge looks like, you're almost able to build this like mental reference of what normal looks like. So then when you're examining a NY with ocular pathology, you're able to identify that easier.
So these would be my main tips I think technique wise with your ophthalmoscope it always helps if you have A fully dilated pupil, because with the direct ophthalmoscope, you get this almost keyhole view of the fundus. Your field of view is quite narrow and the image is quite magnified. So if the pupil is not fully midriatic, it can be quite challenging to have a good view, especially because, you know, with our patients, they don't tend to stay still for long enough. So I would always recommend dilating the pupil before you start doing this technique.
[00:03:10] Yaiza Gomez Mejias: Great. And I also really liked the part of the article where you recommend a methodic approach to the different parts of the fundus.
[00:03:19] Natalia Giannakopoulou: Yeah, definitely. And this is something that we teach our students at the vet school. We normally tell them to follow the systematic approach where you would try to find the optic nerve head first and use it as a reference point. And then I would recommend assessing the retinal blood vessels next and then splitting the fundus into quadratic quadrants and try to examine each quadrant as efficiently as possible as to not miss any little subtle lesions.
[00:03:48] Ben Blacklock: Just a couple of, like, really practical tips. These ophthalmoscopes are not routinely used in your practice. Just make sure the batteries are fully charged. Make sure they're nice and clean, because all the little lenses get dirty. Make sure you can look through it without any major opacities on all the lenses. And then when I was in practice, the cats that I used to love practicing this on was those that were. That had triple anesthetic, so some sort of ketamine anesthesia for routine neutering. Because the pupils are widely dilated, they've got a central eye, and you can spend a minute just practicing your ophthalmoscopy on these anesthetized kittens.
[00:04:23] Yaiza Gomez Mejias: That's a brilliant advice. I love it. Thank you. And besides the ophthalmoscope, is there any other equipment that we could use or that we should be using?
[00:04:33] Natalia Giannakopoulou: Definitely. There's a lot of different options that you can use for ophthalmoscopy, and they all can give you, like, a different perspective, and they have their pros and their cons.
Another ophthalmoscope that you can use is the panoptic ophthalmoscope that basically can attach to the standard direct ophthalmoscope handle. And with this ophthalmoscope, you still get an upright view of the funders, but your field of view is wider, so it can be more easy to have, you know, to see more of the fundus at once, which is helpful for someone who's just beginning and might struggle with the direct Ophthalmoscope and I think other options you also have is indirect orthophalmoscopy and this is something that you can perform with just a light source, you know, like at the otoscope light or a pen torch or even your smartphone flash. And the only thing that you need for that would be a condensing lens.
So yes, these are different options that you can use in practice.
[00:05:32] Yaiza Gomez Mejias: Any other ideas Ben, or just.
[00:05:35] Ben Blacklock: So there's a really nice section in the article about using your smartphone for fundoscopy entirely.
[00:05:41] Yaiza Gomez Mejias: Yeah, I was going to ask you about that as well. But first I wanted to ask you about the lens. Which lens do you recommend for vets working in general practice?
[00:05:49] Natalia Giannakopoulou: So I think if you're a general practitioner you only want to invest in one lens. We tend to recommend the pan retinol 2.2. And because I feel like that lens is a good choice because it gives you a wide field of view but also good magnification. And in general when you're looking into bike lenses, the rule is that the higher the diopter the lens is, the more wide the magnification you're going to get, the more wide the field of view is going to be, but the less magnification you're going to get. So for example, if you're going to buy a 30D lens, it's going to give you a wide, magnificent wide field of view but less magnification compared to a 20D lens. But with the pan retinal it's basically between these two lenses. So you get the both of those worlds. So I think it would be the one to invest if you're considering buying only one lens.
[00:06:43] Yaiza Gomez Mejias: And you mentioned before that you would recommend mediatics in all ocular exams in cats, which mediatic would you go for?
[00:06:55] Natalia Giannakopoulou: So general go to midriatic would be Tropicamind and we would use the 0.5 to 1% concentration and during clinics we use it in this minims form which is basically those little single use preservative free vials that, you know, we open them for each patient and then we discard them. And that is quite hygienic as well. The reason why would we prefer tropicamide is because it has a quite fast onset of action. So within 15, 20 minutes you will get a fully dilated pupil. But also it doesn't, it only lasts for four to six hours.
So comparing this to other mydriatics, that atropine that can last for days, we think this is the best option. If you just want to use it for diagnostic purposes.
[00:07:46] Yaiza Gomez Mejias: Any side effects you we should bear.
[00:07:48] Natalia Giannakopoulou: In mind with tropicamide. I think sometimes it has been reported that some casks can hypersalivate because of the bitter taste. But again, it's not as prominent as other midriatics like atropine. But I think it's always good for general practitioners to warn the owners before applying this eye drop because sometimes the owners would see the cuts, hyper, salivate a lot and be quite scary for them.
[00:08:18] Ben Blacklock: And I suppose if I could again just offer a quick practical tip, 15 to 20 minutes is an awfully long time to spend in a consult room with a client. So we tend to put the eye drops in and put the owners back in the waiting room and see the next case or perhaps even admit the cat. You know, give yourself plenty of time to do this rather than try to cram it all into a single consult. Something like that will make your life much more, much more relaxed.
[00:08:43] Yaiza Gomez Mejias: The only thing I see there is that if the cat starts hypersalivating in the waiting room. In the waiting room and you're not around the owner, that would be a little bit worrying for everyone.
[00:08:53] Ben Blacklock: Yeah, true. It tends to come on quite quickly, quite soon after you've applied the drops. And I think if you've warned the owners that they, that they will hypersalivate, then with the tropicoide it's not so dramatic. If anybody's ever put atropine in a cat's eye, that, that can be really quite dramatic. And again it's fairly short lived. But if you've not warned the owners they could be quite distressed about that. That's true.
[00:09:14] Yaiza Gomez Mejias: And how long does it, does it last, the hypersalivation? More or less.
[00:09:18] Natalia Giannakopoulou: I wouldn't say it lasts for long, maybe a few minutes.
[00:09:22] Ben Blacklock: Yeah, it's variable. I mean some cats seem to be really sensitive to it and will continue salivating and dribbling for a little while. But most cats, it's just a minute or so.
And some dreamies can help, you know, give them some dreamies or some licky licks after you've given them the eye drop. And that seems to take away some of the bitter taste as well.
[00:09:40] Yaiza Gomez Mejias: Dreamies are magic. They're so useful in the concert room.
So shall we get back to the smartphone you mentioned before?
How can we benefit from smartphones in first opinion practice?
[00:09:54] Natalia Giannakopoulou: I think you can benefit in many ways. I think the smart process of now, they're these amazing tools and especially proclamation cases like they have the cameras now are amazing. You can take really high quality photos of the eyes where before you could just, you need to buy, you know, expensive camera for that. And I think it's very important for clinicians to take photos of the eyes during the consults just to monitor the progress and also, you know, in case they would need an advice from, you know, advanced practitioner about the cases.
But also another really cool use of the smartphone is you can use it, as Ben said, as an indirect ophthalmoscope. And if you have a condensing lens in general practice, you can use the smartphone to take really high quality videos and photos of the funders without the use of like an expensive fundy camera or like any special equipment.
[00:10:53] Yaiza Gomez Mejias: And any tips to use them successfully. I know the best thing would be to read the article because it's really, you explained it really well. But any tip you want to share with the audience to encourage them to.
[00:11:03] Natalia Giannakopoulou: Read the article, definitely. So I think, especially if you're going to use your phone to take, you know, take photos of the fundus, my main tip would be to decrease your flash intensity because the flashes in our smartphones tend to be quite bright and that can be quite uncomfortable for the patient, first of all. And it's going to reduce compliance so they're not going to be as still for you to take the video.
So what I tend to do to decrease the intensity in my phone is I tend to use micropo tape, which is, you know, the IV tape, and I put several layers over the flash of my camera and that helps with the compliance with the patients. But also because you're imaging the fundus and the tapetum can be quite a reflective structure. If you have, if you haven't decreased the flash, you can get a very overexposed image. So I always recommend reducing the flash. If you don't want to use the micropore tape, there's always applications that you can download on your phone that can let you, you know, play with your flash intensity. My other very important tip when you do smartphone fundoscopy is to always use video instead of trying to take little photos because it's very important to maintain the axis between, you know, the pupil and the lens and your camera.
So I think it's easier to just press record than trying to, you know, press about and multiple times. I think the alignment is not going to be as easy to maintain.
[00:12:40] Yaiza Gomez Mejias: And you can always pause the video on a particular image or.
[00:12:43] Natalia Giannakopoulou: Exactly. And what I do is I take a long video video, you know, and then I play the video and just Screenshot the best images from that video and it's much better than trying to take, you know, individual photos.
[00:12:57] Yaiza Gomez Mejias: I've got to admit that I've learned a lot about my smartphone whilst reading your article because I didn't know it had so many lenses and that you can, you could regulate the intensity.
What are the most common normal variations in the Feline contest that might be mistaken for pathology?
[00:13:17] Natalia Giannakopoulou: I think one of the most common variations that I've personally seen clinicians mistake for something pathological is the subalbnotic fundus. This is a completely normal variation. We see it in color dilute animals with blue eyes. So think of like your standard ragdoll. And what happens with these cuts is because there's a partial or complete lack of tapetum and also there's no melanin in the retinal pigmented epithelium. Or what can happen is that the underlying choroidal vessels are actually visible and I think give the fundus a very striking red appearance. And I've seen a lot of clinicians that haven't seen this before mistake it for like, you know, a massive retinal hemorrhage or even like a partial or even like a retinal detachment, because how red the fundus looks like.
I think that also goes back to what we said about trying to examine as many normal eyes as possible.
Just so, you know, like, look, this is normal and it's not something to, you know, be concerned about.
[00:14:19] Ben Blacklock: I agree. And I think, Natalia, at work, we'll often see these colour dilute animals with, with a lack of pigment. What seems to especially catch people out is when they have some tapetum, but the tapetum is, is a little bit thin and so you can see some of the choroidal vessels just showing through the tapetum. And people often come and ask us if that's, if that's hemorrhage, don't they? And we go and double check them. And honestly, that's tricky, isn't it? As a beginner, that's a very easy and totally understandable mistake to make. And it just comes down to experience and examining tens, hundreds and eventually thousands of cat retinas, you eventually figure out what's normal and what's not. So there's not really easy shortcuts there. But just being aware that these colour dilute animals will definitely look a bit different.
But every cat's fundus is unique anyway. So, yeah, the more you can look at, the less you'll get caught out by normal variants.
[00:15:16] Yaiza Gomez Mejias: The practice makes Perfect.
[00:15:17] Ben Blacklock: Yeah, absolutely.
[00:15:19] Yaiza Gomez Mejias: We mentioned before how important it is to perform the retinal exam in senior cats.
So what are the key findings associated with the systemic hypertension in those cats?
[00:15:30] Natalia Giannakopoulou: So, yes, we do see a lot of cats, especially older cats, that do have systemic hypertension. They can have this characteristic. Funding changes. Things that you can see as a first, signs that the oxy stomach hypertension changes in the retinal blood vessels. So you might see that the blood vessels become more tortures. You might see changes in the caliber of the blood vessels. So you might have some areas where there's narrowing or aneurysms or even some small retinal hemorrhages. And then as a degree, as the disease progresses, you can also have bullous retinal detachments. And this can appear like. They almost look like little blisters in the tapeal fundus, and they're basically accumulations of fluid behind the retina. And of course, in advanced cases, you can see a full or partial retinal detachment. And in these cases, you will see that the retina looks almost like a veil billowing forwards behind the lens.
And you can also see that even without fundoscopy, sometimes it's visual just by shining a light in the cat's eye.
[00:16:39] Ben Blacklock: We'd love every practitioner to do a fundus exam at every routine checkup of an older cat. Well, any cat, of course, but especially the older cats, because this is probably one of the most satisfying things to pick up as well, because you can follow the blood vessels and the lesions are often associated with the blood vessels. So really, really satisfying diagnostics to use.
[00:17:00] Yaiza Gomez Mejias: It can be also useful in infectious diseases. Some infectious diseases can cause ocular changes, and a thorough tonic exam can help, especially in those that are particular difficult to diagnose.
For example, how can the retinal exam aid in the diagnosis of villan infectious peritonitis?
[00:17:20] Natalia Giannakopoulou: Yeah, I think ophthalmoscopy actually can be really useful for the diagnosis of FIP.
And there's a lot of cases that we have seen actually present with ocular signs first, and then this leads to clues that something more systemic is going on. I think the most characteristic phonic lesion in cats with fip, what we call perivascular coughing, which basically looks like a white or fluffy sheath around the retinal blood vessels. And they can. And this can happen because this granulomatous exudates along those blood vessels.
And this can be very characteristic with diseases like FIP.
[00:18:02] Ben Blacklock: And of course, now that we can treat FIP, this is absolutely crucial to every cat that's suspicious to have FIP. We should be doing an ocular exam because that's going to affect the treatment we use, you know, the dose rate we use. So this has become really important in the last few years especially.
It can be tricky, can't it, with some of the subtle lesions are difficult to spot. But I know this article's about fundoscopy, but you'll often have signs of anterior uveitis with FIP as well, which will give you a big clue, perhaps a little bit easier to pick up sometimes in practice.
[00:18:37] Yaiza Gomez Mejias: In the article, you talk about the difference between active and inactive chorioretinitis and some of the endoscopic differences between them.
Would you like to briefly mention?
[00:18:50] Natalia Giannakopoulou: Of course, the lesions between active and active choroiditis look quite different.
So in active choro retinitis, because you have inflammation in the retina, the lesions can appear raised. They are hyper reflecting because of the retinal edema. Usually they have blurred margins. You can also see lesions like retinal hemorrhages or partial retinal detachments, depending on the severity of the choro retinitis. In contrast, when you have inactive choro retinitis, what you normally see is chlororetinal scars and they still look quite different.
So they look like, well, demarcated areas of hyperreflectivity, which happens because the retina degenerates in the areas where of the previous inflammation and that causes the hyperreflectivity. And you might also notice some pigmentary disturbances in the tapetal fundus where you have dispersive pigment or also depigmentation, the non tapestryal fundus. And that's how you would make the distinction between the two.
[00:19:57] Yaiza Gomez Mejias: I thought it was going to be really difficult to do a podcast on retinal exam because images are so important.
Yeah. It's amazing how you find the words to explain all these things.
So I really admire the capacity you have to articulate. You know, it's been really easy to visualize what you've described. Could you recommend an atlas of an ophthalmology atlas that our audience could perhaps use to see more retinas at home without the cats in front of them.
[00:20:35] Ben Blacklock: There are a couple of nice atlases. There's a feline ophthalmology textbook.
Whose is that one, Natalia?
[00:20:43] Natalia Giannakopoulou: This one is gelatin plumber and it's called Color Atlas of Veterinary Ophthalmology. It doesn't only have cats, there's all species as well.
[00:20:53] Ben Blacklock: There are at least two cats ones. There's one by Keith Barnett which he can still get. Now some of these atlases are quite old, but the pictures are just brilliant. There is a veterinary ophthalmology textbook as well by Natasha Mitchell and James Oliver which has got lots of great pictures in as well and lots of schematics to help you understand the pathology going on. Perhaps we can send the names over, maybe put them in the podcast notes or something like that.
[00:21:20] Yaiza Gomez Mejias: We will, yeah. If you send them to me, we will put them on the notes.
[00:21:23] Natalia Giannakopoulou: Yeah.
[00:21:24] Yaiza Gomez Mejias: Brilliant advice.
Thank you so much. Thank you so much for joining us and especially today because of being a bank holiday. Thank you so much for writing this article because it will be extremely helpful to practitioners.
[00:21:38] Conclusion: Thank you for listening to this episode of All Cats Considered. We hope you enjoyed this interview. For more information on the topics discussed in this episode, please head over to catvets.com podcasts and explore. Explore the links in the show Notes. Don't forget to subscribe to this podcast on your platform of choice so you won't miss any episodes as we release them. Have thoughts or ideas about the interview you heard today? Share them with us by leaving a comment on our Facebook page or shoot us an email
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