 All right, so this one's gonna be a little bit of a shorter lecture compared to that last one we did. We're gonna talk a little bit more about infectious keratitis, but we're gonna cover some of the viral things that you see. So we're gonna go through the viral causes of keratitis. We'll talk about how to create a differential diagnosis, which is fairly simple in this situation. Some things to be looking for to try to determine what the correct etiology is. What we do for testing, and then thinking about some of the other things that are going on when you have the viral keratitis. Some of the long-term consequences are a lot different here compared to bacterial keratitis. And then we'll talk a little bit about recurrence and treatment and prophylaxis. So when you're thinking about viral keratitis, really the causes are herpes, herpes, herpes, herpes. And then you have Epstein-Barr virus, CMB, which can sometimes play a role, but most commonly these are herpes viruses. So the ways to sort of think about what's going on with the patient that comes in with keratitis when you're thinking of viral etiologies is trying to figure out what's involved in the cornea. So is this an epithelial process? Is it the stroma? Is it both? Is it the endothelium? Is there an anterior chamber reaction? Is there inflammation going on? Do you have a hypopion? Do you have high pressure? So you're trying to just figure out what part of the cornea is involved. Some of the various characteristics of the virus is so if you're thinking about herpes simplex virus, typically the classic finding is epithelial dendrites. And the dendrites in this situation will have kind of a terminal bulb on the end of them. If you compare some other things that you can see, they try to differentiate the iris translation defects. So the herpes viruses will have translumination defects in the iris. And typically there's more of a diffuse iris translumination problems with simplex compared to zoster that will have more of a sectoral defect. Then you're thinking about, if you're trying to say, okay, is this herpes or is it zoster, zoster has more of pseudo dendrites. Who could tell me what that is more so than a dendrite? Is that like elevation in that ability? They're definitely gonna be more elevated, but they both can be. You're trying to, you're more looking for dendrites that don't necessarily have that terminal bulb on the end of them. And I'll show you some pictures of what these look like. But when you're looking at the iris, you might see just like a sectoral translumination defect rather than kind of diffuse iris atrophy. When you're looking at EVV and CMV, these typically present with like an endothelitis. And so you'll have some decimates folds and it's a lot of times kind of like a plaque or sort of a round area of endothelium that's affected with overlying corneal edema. And then you can have an anterior chamber reaction in pretty much any of these. So any of them can present with iritis. So this is a pretty typical look for herpes simplex. You can see kind of these crusting lesions here. In this guy, he had kind of a conjunctivitis as well. And so it's pretty typical to have something kind of going on around the mouth or around the nose and then their eye will be red. And so you're, this is what you would think of with herpes simplex. Another one that's pretty bad here, herpes simplex conjunctivitis clearly. And then a pretty bad rash around the nose. So this one, what do you think about this? Somebody describe this for us. Now they're different. These are two different pictures. So you're seeing a bunch of kind of patchy stromal haze. This is pretty typical of what simplex will look like later on when you just have stromal involvement. It just kind of looks like this hazy cornea. You're not exactly sure what's going on. Is it an old scar? It's kind of what it looks like, but that's a pretty typical appearance. And then this is kind of a big ulceration of the cornea, which is typical as well for herpes simplex. And you can see, like if you're thinking, you see somebody with an epithelial defect like this and you're wondering like, what else should we be thinking about? What kind of stuff are you thinking in this situation? Other than herpes. Yeah, so what's different about this compared to bacterial ulcer? You're thinking about what it looks like. Yeah, so you've got kind of this surrounding haze, that comes clear away from the area that seems to be the most affected. You've got this ulceration that looks pretty clean, right? It's not soupy. It's not really white. There's not a lot of mucus coming off of it. The area around it looks pretty quiet. So that's pretty typical of a herpes simplex ulcer. What else? What else would you be thinking about in this situation? It's maybe in the lower half of the cornea. Could be staff marginal. These are usually elevated, pretty white looking. Sure, yeah, definitely chemical can look like that. What if this person is on the burn unit and they can't close their eye? So exposure, that's probably the hardest thing to differentiate in a lot of cases is exposure, keratopathy versus herpes simplex. Because a lot of times they're kind of in similar places and they look kind of similar, too. But if you cultured this or sent for PCR, you would probably come up with a diagnosis there. Okay, what about this one? Niko, what do you think? Describe what it's looking like. It's surrounding it more. Yes, you've got, this whole cornea is pretty clear over here, right? Yeah. It's kind of normal. Then you get into this kind of patchy haze. It's kind of coming off the limbis a little bit. There's not a lot of vascular tissue coming in. And so you've got kind of this round central hazy spot right in the center. And this is pretty classic for this disciform keratitis, which you see in simplex as well. All right, what about this one? Reese, what do you think on this one? Just thinking kind of patchy areas of the haze that seem to be kind of more deeper than the other picture. Deeper, like, miserable vessels kind of just... Yes, you'll see a lot of patients with this. They'll come in and say, I can't see. It's been going on for a week. What do you think? I think it's been going on for a week? No. So it takes a while for these blood vessels to grow in, right? So they're kind of a response to inflammation. It's been going on for a really long time. So with interstitial keratitis, the top thing on your differential diagnosis is herpes simplex. And pretty classic that you get these big, ropey vessels coming in. You'll see haze kind of at the edge of the vessels. If it's kind of white, then it's usually just the herpes part of it. If it's starting to turn yellow, then you're thinking more of lipid deposition into the cornea. Zoster doesn't do that? Zoster definitely can do it as well. Sometimes it's hard to differentiate which one it is because in many cases, this is not like an active infection. This is more of like the immune response to the herpes virus. So it could be either one. You treat it pretty much the same. Try to treat it with some topical antiviral, see if it works, if it usually doesn't do anything, but steroids can sometimes help. There's been a lot of different ways that people have talked about treating this. Some people try it. You can put a vasin sort of at the limb, just try to get these vessels to regress. Steroids can work. You can actually go in and ablate these vessels with either an argon laser or a cotterie. You can actually suit your vessels closed if there's like a really big one that won't close with cotterie. In a lot of cases, these will kind of regress with time and steroids, but some of those other interventions can help too. What if you were to say, okay, this is four years later, we've tried everything? What's the next treatment? This is what it looks like four years later. It's not getting better. Their vision still sucks. What would you do before that? Would you exhaust before cornea transplant? See this nice clear area up here? You can smooth out some of the irregular stigmatism with a potential contact lens. Might be able to buy them sometime. Try it, send the optometrist, get a contact lens fitting. If it doesn't work, then you're looking at a PK. So if I'm thinking, okay, I'm gonna do a cornea transplant on this patient. They probably have a herpes virus. What are some of the issues that I'm gonna deal with? Definitely, reactivation. So what are you gonna do? You need prophylactic or treatment dosing, right? So you're gonna put them on treatment dosing acyclovir, probably a week prior to surgery, and then you're gonna keep them on it for probably six to eight weeks after and then kind of slowly taper off acyclovir or Valtrix. What else? What else is an issue with these diseases? Sometimes they, they won't. Yes, the first step of a cornea transplant healing is getting the patient's skin to grow over the donor, right? And that's gonna take a while in herpes patients in a lot of cases and sometimes it won't ever heal. And so in these patients, we tend to do a Tarsorphy at the time of PK to try to help them. And a Tarsorphy would pretty much close the eye and you give yourself a little slit to look through, but just to make sure that cornea is doing okay. But just keeping the eye closed as long as you can is sort of the best thing for them in these situations. Is that because of the neurodermal pain? Or is it because of the... That's the reason they don't heal. Yeah, they're essentially, their corneal nerves are shot. That's where these infections effected. A lot of times it's the corneal nerves and so they have decreased corneal sensation. They have decreased growth factors and so the skin just doesn't grow as well. The last thing that you're at really high risk of is rejection that has nothing to do with the virus, right? It's just the cornea has a higher risk of rejecting because of these nasty blood vessels that are already gonna be at the graft host junction, right? And so sometimes you have to treat these patients with oral steroids or higher dose steroids for longer. And you run into complications of glaucoma, high pressure, sometimes they end up with a tube or a shunt of some kind. So these eyes can be a lot of trouble to recover. And so when you're having discussions with patients, okay, let's do a PK. A PK in general puts you at risk of glaucoma, just even in a normal patient. And so you have an even higher risk in somebody who has herpes simplex virus or some other interstitial keratitis just because they're at high risk of rejection. You're gonna have them on high dose steroids that have higher risk of ocular hypertension than glaucoma. And so it's a tougher decision to make when you're in these situations. But that's what we do. We're an academic institution, we do a lot of these cases. I think you would initially test for everything. TB is something that you definitely wanna treat. Syphilis is something that you definitely wanna treat. So those are probably the two most common things. Sarcoid is another one we tend to test for. It's hard to make the diagnosis in a lot of cases as to what's going on. So you kinda treat it in a lot of cases like herpes if you're moving forward on treatment for surgery and things. So this is kind of a picture of diffuse iris atrophy. You can see a lot of transillumination defects in, I don't know if this is just a white-red reflex or I think it's just the camera that did that. But you can see all these transillumination defects that are just kinda chewing up the iris all over. That's what you would typically see in herpes, simplex case. All right, somebody describe what this one's kinda looking like. On the count of the infrared precipitates, especially if you're... Yeah, so you're kinda looking in here. You've got all these little dots here. You've got a few down here. It's pretty tough to tell on a straight-on image, but probably some endothelial involvement, right? And a pretty angry eye, right? You got all this limbo flush with all these blood vessels coming in. So I love these terms. You've got keratoconjunctivitis. Those are kind of ways that you can sound smart. I have a patient with keratoconjunctivitis. Their eye is red and their cornea is hazy, right? Or I've got a patient with keratoconjunctivitis. Their cornea is hazy and they've got an anterior chamber reaction. And so that's gonna be at the top of your differential. It's the herpes simplex virus is in a situation like this where the cornea looks kinda hazy, probably a little swollen. You've got inflammation. The surface of the eye is obviously involved. A lot of cases the pressure will be up in this situation as well. And so, Reese, what would you do to treat this? Probably give them like a high-dose acycloary. After they've been on that for a little bit, start some steroid. Yeah, give them a couple days of acycloary for sure. Get them going on it and then probably start steroids pretty quick. When you have inflammation inside the eye, the sequelae of that is bad, right? What are some of the issues you run into if you have anterior chamber, iridus? What are some of the long-term consequences? Sneak eye. Sneak eye, which direction? Both, right? I mean, the iris is inflamed. It's gonna stick down to whatever it can touch. And so you wanna get these patients with their pupil dilated, right? I hate atropine in these situations because what atropine does, it brings the pupil really big and then makes it sit there. It doesn't move. When you put somebody on like cyclopentylate, their pupil will dilate and it'll move a little bit still because it's not as strong of a dilator and so it'll prevent some of those posterior scenicae. Why don't you use it? I don't use it. I don't use atropine very often. Retinocases, they can use atropine, but there's not really a reason to use it otherwise. The other thing is that patients come in and they're like, why the heck is my eye dilated? And it's been like two weeks because lovely atropine. And you can actually get some iris atrophy from atropine too, where the pupil kind of stays a little bit big. So yeah, you wanna dilate them because if their pupil gets stuck down and it's two millimeters, it's not good. You can't see what's going on the back of the eye. You have to go into surgery to sort of expand the iris sometimes. And a lot of times you'll potentially create a cataract when you're trying to do that kind of a surgery. So try to get their pupil dilated. They're also more comfortable. Chris, why are they more comfortable if you dilate them? Because it's painful when their iris is for spasming from the inflammation. Yeah, you got some inflammation going on in there. Their iris is spasming, the salier body spasm. So if you can dilate them, it'll get rid of that as well. So they're a little more comfortable. It's kind of catch 22. You're like their eyes light sensitive. So I'm gonna dilate them, but it's more of that salary spasm that drives them. Lines on the cornea. You don't see lines on the cornea, right? That's not a natural thing. So this is just kind of a weird endothelitis. What if this patient had a PK out here? So this would be like one of those rejection lines you're worried about. When you see this, what's happening is you're getting destruction of the endothelium kind of on this side and it's heading out this way. It's like the marching of the army that's heading out to destroy the cornea. So if you can halt it here, their vision will be fine, but if it gets out into here, into the center of their pupil, then they're in trouble. So HSV endothelitis. When you see endothelitis, it really could be any of them. It's hard to distinguish which virus it is. Luckily, you can kind of treat them all the same. When I don't know which virus it is, I treat with bow treks because the dosing is the same. Give them a thousand milligrams three times a day. What if you're treating simplex, Ashley? What do you do? What dosing are you doing usually? Yeah. No, sorry. Simplex. Simplex. Oh, 400. Simplex is 400, five times a day, or 803 times a day. Same dosing, right? Probably get you the same antiviral load. Whereas with Zoster, you're giving a higher dose, so 800 milligrams, five times a day. Or bow treks three times a day. Or a FAMV or 500 milligrams three times a day. Lots of different ones. Sometimes you run into patients who have side effects from the antivirals, so you have to kind of class switch and figure out which one they can handle. Okay, what about this one? Mike? Little spots in the face, and where are the ones described? Yes, you've got all these little spots here. They're all in the endothelium. You can kind of tell where they are in this picture, but it's hard for sure without being able to sort of adjust lights and things. If you go right along the back of the endothelium here, you can see that this one kind of jets out, and this one kind of jets out now, maybe. So you can still tell in this picture that it is sort of on the inside layer of the cornea. These are the pictures you're gonna get on boards, and you're gonna be like, how am I supposed to know what depth that's at? I don't really know. But you say, okay, what in the cornea looks like that? KP look like that. It's about just kind of looking at lots of different pictures. So there's that term that you can use. It's keratoyubitis, you've got cornea involvement with the uvea of some kind. So keratic precipitates. Okay, how about this one? I know I labeled all these, but it's good to just describe them and talk about them a little bit. Want to take it? What are you seeing? On the left, I mean I see. Yeah, the one on the left. Looks like Diplocinate in the purple cornea, and I don't know if it's just granted, it's melting in the middle, but it's kind of like a gelatin appearance. Good. And I mean, I don't know if you see some kind of blood in that mid-gelatin kind of darker spot. This spot here? Yeah, I'm not sure that's blood or what. It's iris. Oh, okay. But why do you see iris there? There's a perforation. Maybe, could be, but along the same lines, there's thinning, right? So if you've got an area, this is something to watch for on exams. This is the type of case where you would want a Seidel, because you're not 100% sure how thick the cornea actually is. You can sort of tell in this picture, you've got kind of a thick beam of light here, and then right here, it changes, right? Rather than being sort of convex, it switches to concave right there on that beam. So the beam's a little thinner, so it's telling you that it's kind of excavated like you were seeing, like a melt, so it's thinning there. And then you've got these areas where it's pretty diffusely hazy, and then all of a sudden there's a spot where it's kind of clear. And you worry about that spot being really thin, because otherwise if there was some meat of cornea that's thick and hazy, you'd be fine, and you wouldn't be able to see the iris. So you essentially have an ulceration of the cornea. In this situation, if this patient first presented to you, this could be anything, right? So they're not complaining of any pain. It's pain-free. Zero pain, they just can't see. So that's telling you, okay, the corneal nerves are involved here, they're kind of shot. So you're thinking more along the lines of a herpes virus, but you're gonna culture this for everything. Reese, what are you thinking about if you're gonna culture this? What are you gonna do? You're gonna scrape right there, right? So in most cases, you wanna get down to the base of the ulcer. In this situation, you wanna stay away from thinning areas. And so you might scrape kind of on that down edge, sort of out here, over here, and you'd wanna send this for viral PCRs and all the bacterial cultures. What about the picture on the right? There's a little spot that's labeled. So you've got kind of this hazy cornea, not a lot of inflammation sort of around it, but you can tell that the conge is pretty injected, inflamed. This area is maybe missing the epithelium, maybe not. Then you've got this one little spot. It almost looks like a metallic foreign body, doesn't it? Well, this one, I guess, according to catchmer and palate, crashmer, sorry. This is a little perforation in the cornea with the herpes etiology. They had a cydel test on it that showed that it was positive. So you can tell herpes simplex is kind of tough, right? It can present as a lot of different things. There's, it's always gotta be on your differential diagnosis. Always gotta be thinking of it. Luckily the treatment is pretty safe, right? Valtrex is kind of expensive. That's the main side effect of it. It's hard on the wallet, but otherwise it's a safe medication. And Dr. Tabin always used to say, why is it safe? Why is a syclovir and valicyclovir? Why are these medications really safe in patients? What's the key to their activation? Yeah, so they are activated. They're only sort of converted to active drug by live virus, right? Otherwise the body just passes it right through. Doesn't use it. So that's why it's a nice safe medication. Who do you have, what sort of things you have to watch out for if you're gonna treat somebody with a syclovir? So kidney function, I have to reduce your dosing because it gets cleared by the kidney, right? That's the main thing. Question. So, what do you do oral versus topical? Since then we just do oral, I know some patients come in a lot of times and they're on topical. Yeah, so topical antivirals are good for epithelial disease, essentially. So in somebody with classic dendrites, I treat with, I would treat topical. Pretty much no other time, honestly. Because it's a very expensive medication and there's not a lot of data out there to suggest that it's helpful. But if their epithelium is involved, yeah. So if they had like that meta ulcer, that big ulceration, you might think about it too. Epithelial, just epithelial. Not great studies. If you look at the head's trials, the topical really did nothing, but it's hard to know. I mean, you're essentially just getting, because they were all on oral, a syclovir too, so you're getting a high antiviral load both ways. But in sort of clinical practice, it seems like it's helpful. And the whole, the reason why you're trying to get their epithelial disease to resolve quickly is because of the scarring that can happen the longer it sits, they're sort of ulcerated. All right, what about this one? Yeah, so pretty classic. You can almost draw a line right here, right? Maybe not, you got a few over here. This guy's dermatomes didn't quite follow the perfect pattern, can't quite draw a straight line, but pretty much, right? This is a dermatomal rash. So we've had patients like this that have been misdiagnosed that end up in ophthalmology and we diagnosed them with it. I had a patient one time that she, I don't remember who saw this patient, ER. This was, it was probably two years ago. Came into continuity clinic for follow up for a chemical, chemical injury. So she was a construction worker and a bunch of concrete dust sort of got kicked up and blown towards her and ended up in her hair and kind of on one side of her forehead and she came into the ER. And they said, that was the chemical issue. They sprayed her down and cleaned her up and sent her out. She went to her primary care doctor. This is just a chemical burn. She had some scabs on one side. She had her hair was like hurting her when she would shampoo on one side. And I see her in clinic and I'm like, okay, so help me understand how a chemical just hit you on one side of your face and hair and we looked inside her hair and she had all these scabs kind of all over just in like a V1 distribution. So treated her with antivirals despite her primary care doctor being adamant that she did not have Zoster and she got better, but it was just kind of funny. So this will happen a lot where you're like, this is clearly Zoster. Like we just treat it with antivirals, give them a full 10 to 14 day course and call it good. What are some of the consequences of Zoster that you worry about? Definitely corneal scarring. Yeah, good. Yeah, so you can get sort of encephalitis from this. You can get that from simplex too, but yeah. What other, what nerve runs right with seven? So you can a lot of times for some reason, eight gets involved. So you have to ask people is your hearing has been an issue? So I had a patient just like two weeks ago came in for Zoster, he had keratitis. So he had a little bit of whitening of his cornea. He had pretty much completed a full dose of acycloviric, but I just said, how's your hearing? And he's a 75, 80 year old guy, he has hearing aids and he said, it's been getting worse over the last couple of weeks, like significantly worse on the same side as the rash. So how do you treat these people? Steroids, right? You have to give them oral steroids to try to prevent their hearing loss from getting worse. So I gave him a medriall dose pack, sent him back to his primary care doctor to sort of watch out for his hearing, because they can have pretty significant hearing loss from this process. What else, kind of a long-term consequence, way down the road that has nothing to do with their corneas, huge issue, right? Major issue, these are the patients that drive you nuts and ophthalmology, because they have eye pain and it's post-tropetic neuralgia and you can do absolutely nothing for them. Gabapentin, Neurotin, those medications can sometimes help, but you've got to get these guys into a pain specialist if they're having that. So the thought is, there's pretty good evidence in the literature that if you start the medication early, acyclovir, antivirals, then it can prevent post-tropetic neuralgia. So typically within the first five days is what you want to do, but. Sometimes these are tricky to diagnose early on. I had a patient that showed up to Dr. Mifflin's clinic, she had cataract surgery, was doing great, was complaining that her neck was kind of sore, had some swollen lymph nodes sort of on that side, but everything looked pretty normal. I don't know what's going on. She comes back two weeks later, big old rash. She had been treated by her primary care doctor and we're like, oh, that's what it was. So the zoster's kind of tricky. You have to sort of pay attention to that when people are complaining of sort of one side of pain, swelling, thinking about zoster, because a lot of times it'll come on with that sort of sensitivity of the skin before a rash pops out. All right, somebody describe these dendrite looking things. What'd you say? Sort of, right? The terminal bulbs are usually a little more clean than this. So these are kind of like, I don't know, they're just kind of branching corneal lesions that stain with forcing, right? Branching corneal lesions that stain with Rose Bengal. But a terminal bulb, I think I have one in here, is like a really big spot right on the end of these little branches. So this is kind of a pseudo dendrite, is what you call it, with zoster. Kind of a tricky one. You can see a patient with this, little subepithelial infiltrates. See some corneal nerves here. Another sort of slit beam of it, showing you that it's just in the anterior stroma. Really superficial. So this could be signs of an old keratitis that was caused by zoster. Could be a viral keratitis, like adenovirus, or one of these other ones too. So this is a classic picture of neurotrophic keratopathy. So this is a very tricky one. I've had a patient come in like this, and I wanted to treat with broad spectrum antibiotics because I was really nervous. We cultured it and treated him with steroids. I was scared. He got better. I would have done something different, but he did fine. It was clear that it was sort of a neurotrophic situation in his case. But an angry eye with a hypopia on, you're thinking infectious, right? So you're gonna culture this. You may put them on some antibiotics and kind of nurse this back to health. A lot of cases, these need tarsorophy. So you need to get their eye closed. You can tape tarsorphy them if you're not really sure what's going on. So you just essentially have them close their eye and just put a piece of tape right on their upper lid. That'll keep their eye closed a lot more than having it open normally. So this is a case where this guy is tearing way too much. Listen to patients. I had a big gush of fluid yesterday and now my eye won't stop watering. They're calling you on the phone. Use tears, right? Your eyes just like responding to something. Flush it out. We might flush out their iris and lens if you're not careful, so. You see just kind of whitening on the cornea and then there's kind of a thin area right there. This is a positive Psydel test. So somebody explain why it looks like this. How do you do a Psydel test? How do you interpret it, Nico? If you put the fluorescein in the suspected area of perforates coming out, you would see the evolution of that and maybe showing that kind of dark spot. Yeah, so this is the area where the fluorescein's getting cleared, right? This is sort of your thick fluoresce. When you put really thick fluoresce on there, it almost looks black initially. And then you'll have aqueous kind of clearing it and kind of streaming down. Sometimes these are kind of subtle. When I'm usually doing Psydel tests, I have my finger on their upper lid and I'm wiping the fluoresce on. If I don't see anything obvious, I actually push just very gently on their globe, very, very, very gently to see if you can get an efflux of fluid somewhere. If you push hard enough, you might pop the eye open, which is not good. So you just have to be really gentle with these kind of situations. But this was a zoster case that perforated. This is what you'd kind of see in zasters, kind of this sectoral iris atrophy. So you can see this just kind of ratty iris. Clearly something's happened to it. A lot of these patients have not had cataract surgery, so you can't blame it on a cataract surgeon having an iris come out of a wound and back in the eye. So that's pretty typical of what you'd see, kind of normal iris next to areas of ratty looking iris. Okay, so how are you gonna test for herpes? So in most cases, you just swab it and send it for PCR. Don't culture viruses, get a PCR. They're a lot more sensitive. Sometimes you have to get into doing an anterior chamber tap, especially for CMV and EBV. Checking corneal sensation can kind of help you understand that this is a virus, because there aren't a lot of things that cause damage to the corneal nerves that cause a neurotrophic keratitis, keratopathy. So check corneal sensation on subsequent exams. It shows that they're at high risk of having issues in the future with sort of epithelial breakdown and thinning and all kinds of stuff. So you wanna know what the status is of their fifth cranial nerve. Okay, so some things that are sort of sequela. I think we've talked about most of these, but neurotrophic keratitis, interstitial keratitis, get recurrences with stromal and anterior uveitis. This is the reason that you dilate everybody with uveitis, right? You got a patient who comes in with anterior uveitis. You need to dilate them and make sure that there's nothing going on in their posterior segment. Cases of retinitis have definitely been missed because patients aren't dilated. And these are blinding issues. Having acute retinal lacrosis or progressive outer retinal lacrosis, they need completely different treatment compared to just an anterior uveitis. Posteropetic gnarals are really common in zoster. Same thing, neurotrophic keratitis, stromal haze. If you see whitening in a patient with zoster, they need more steroid. So if you've got their epithelium healed and they're white, more steroid. They come back, they're clearing up, then they come back, they're white, more steroid. So sometimes these patients, you're trying to taper them off of steroids to avoid some of the side effects and they're just steroid dependent to try to keep their corneas clear. Same thing, retinitis. CMV, EBV, kind of long-term endothelial failure, corneal edema, synechia, with anterior chamber stuff, sort of similar things that we've talked about. Recurrences, we just talked about the zoster. It's an immune response. You need to treat it with steroids. And most of us kind of chicken out and give them antivirals, even though they don't really need them. Once they've had one full dose and full course of antivirals, they don't really need them again with zoster. HSV is different. A lot of times you prophylaxin. If I personally had herpes simplex virus on my eye, I'd be on acycler for the rest of my life. But some people, you try to get them off of it the first time. And if they recur, treat them for a year. If they recur again, then sometimes you'll just keep them on low dose forever. 400 twice a day, 800 once a day, something like that is kind of a prophylaxic dose. So primary infection with, it's usually gonna be an epitheliopathy with simplex. So you've got the acycler, 400, five times a day, 800, three times a day, top organ cycle there. With zoster, it's a little bit different dosing. Hearing loss, we talked about, I like Valtrex in some of these situations. It's more expensive, but easier to take. Again, we talked about this already, immune reactions on the recurrences. Okay, questions about viral stuff? Okay, all right, what time is it? We'll go through a few slides of just kind of talking through some keratitis. Bernaysal, do you think it's active or inactive? Yeah, it doesn't really look all that angry, does it? You can't see the conch to see in this situation, but the cornea looks pretty clear around the spots, right? So it's probably inactive. So it hallucinates a little bit with me. If I just like draw this line in here, you see this branching. Sort of branching here, branching here. Maybe this was a big terminal bulb, another branch here. So this is kind of like a ghost scar from an old herpes simplex virus infection. And so this could be what you're left with. Sometimes this patient would see 2015 with a contact lens. You'd be kind of surprised. Sometimes their vision's kind of crappy, but that's pretty typical of sort of a scar you would see after a simplex infection. All right, what do you see here? You might have to think back to different lectures. Chris. So it looks like there's no uphill defect, but there is some scarring probably. You can almost see some of the branching again. It's weird branching stuff, right? Lines in the cornea, Peta. It's just like, what is this thing? Sort of, what can give you like a dendritic pattern? What kind of things? So simplex. Simplex and zoster, right? Biggest things on your differential. So it's not one of those. Something else. Some other sort of type, maybe bacterial. I don't know why that would be branching though. So this one happens to be a canthamoeba. So a canthamoeba can give you dendrites, dendrite looking things, but they're not crisp dendrites. They're not normal looking dendrites. They just kind of give you, it's like, is that a dendrite? Maybe. And the cornea is gonna look quite a bit different, but this was an a canthamoeba patient. Obviously they're gonna have like a history of your contact lens use as well. Let me think about this one. Lee, you wanna take this one? Sure. Very good. What class are you in in high school if you're looking at a picture like this? It's this geography, right? Yeah, that's right, sorry. I don't know, what country are these at? You know, this is a geographic ulcer, right? That's what they call it. It looks like countries in the middle of the ocean. And so this is a big, huge ulcer that you might see with a simplex infection. So this is the sort of geographical representation compared to the dendritic presentation of this. So this is a bad epitheliopathy. This is gonna be a tough one to treat. Mike, wet or dry? Wet. Very wet, right? Very wet, very inflamed. Caridoconjunctivitis, it's a big fancy term. Supe. I like that description. So what do you think it is? Supey, nasty ulcer in a contact lens wearer. Very good, pseudomonasic. Okay, so what do you think about this spot right here? This spot right here, maybe right here? Yeah, so this might be one that would shock you and it's side up positive. Cause there's so much supey junk in there, you're not really sure. But in this case, it's not. It's just really thin in those areas. So you just have to watch them really close. So in this case, we would treat it topical. You could potentially even just go straight to Tobra and Ceptas, double coverage for pseudomonas. If it gets any thinner, we might throw some glue on there. We're gonna try to buy some time because this patient, if we had to treat them now, they would need a total cornea transplant. Cause you'd have to cut out the entire cornea cause you couldn't suture to this. So this patient's at really high risk of losing their eye. You're gonna wanna do a gentle B scan on this patient to see if they have actual end ophthalminus, which would change your management. Okay, so pseudomonas, nasty, disgusting ulcer. We can actually think about the hospital. Is it, so they don't have any eyelashes there, right? So is this like a burn patient? I don't know about this patient, but sometimes no eyelashes just means they've been chronically inflamed. This ulcer's probably been going on for a while, presenting late in the game, but don't really know. Could be. Wow, this one. Niko? Just kind of, maybe it's troll wall or maybe even deeper. I think it's like a ring. Let's look at the thickness a little bit. So uninvolved cornea, right? Right here. Corneal thickness from here to here. We go down here, what's the cornea doing now? It's thicker, right? So there's some edema. And then you come down here, and it may be pretty similar, hard to tell. Might have some thinning there. So you've got a ring infiltrate and an angry eye, contact lens work. Classically, achanthamoeba, right? Okay, Jack, what do you think? So this is a classic sort of terminal bold case. So you can see like a pretty clean ulcer with these nice little spots on the end that kind of go big. When you see a zoster case, they're just kind of branching and they're not usually gonna have that nice terminal bold on the end of it. So this is a good one to treat with cancylvier and oral antivirals. We saw this picture before. What are these? Maybe. They're crystals. It's a crystalline keratopathy. It could be fungal, most likely. What's the most common sort of board answer for crystalline keratopathy? Strep, right? But it could be a lot of different things. This case actually was a confirmed enterocacus. So you just have to scrape them and figure out what it is. Scrape the same place, like dirt. Yeah, you wanna go for the, probably this area here. Kind of where the meat of the ulcer is. We see this picture already? It's a different one. What is this? Reese? K.P., right? Carolivitis. So it could be anything, right? You're gonna check this patient usually for TB, syphilis and sarcoid just to cover Dr. Vitale and then figure out a treatment. It's kinda tough, it's hard to know for sure. All right, good job. If you wanna do well in cornea, you have to look at pictures because the boards, they're gonna give you pictures like this and ask you really obscure questions. And so you have to really look at a lot of pictures, get a good atlas. This Cratchmore-Paley atlas is pretty good. Cratchmore-Paley cornea atlas. I think we have a couple of pretty good atlas upstairs.