 So just to give you guys a little bit of background on what's going to go on in the next 14 path lectures Basically, we go through the BCSC book Today you get a little bit of a reprieve because today's just going to be an introduction to path And so we don't you know have a whole lot of the BCS book on introduction so you get a reprieve But next Tuesday we're doing lid and you're responsible for everything in the BCS lid section prior to the lecture We'll expand upon it. The way I like to do it is I'd like to ask you guys to tell me what's on the slide not vice versa Okay, so we just go around the room and you guys can kind of tell us what you're seeing and You know expand upon a little bit the other thing that I get to do is you are a captive audience And so as a result I get to show you my travel slides. And so usually the slides will be the Place where the ESCRS was most recently and so the SCRS was in Vienna this year So during the next several weeks we get to the Vienna. Okay, so this is the old cathedral They've been kind of renovating it for I mean since I first went there eight years ago So it's one of those constant renovation lines, but this is the the old cathedral It's very weird because it's got this bizarre art deco roof to it Which doesn't quite fit a medieval cathedral. It's very very strange But in any event this is the big cathedral in the middle of Vienna. Vienna has this huge Pedestrian mall that you kind of walk up and it's got shops and restaurants and places to get you know coffee and beer in the middle So this is kind of the center of the old city And here again, you can see they've really done a nice job of Cleaning up the towers And so hopefully the next time I go there in another 10 years it will be completely renovated And of course there's statues everywhere, you know, this isn't one of the old statues So what we're gonna do is as we go from lecture to lecture you guys will get a little tour of Vienna all right, so Eyes now we can't know and understand Hypothology until we understand embryology So we're gonna spend a little bit of time Talking about embryology and what's interesting is you look at a mouse embryo At the same stages of development as a human embryo, and they look very much the same And so you really don't see a whole lot of differences And so a lot of the studies that have been done on embryos have been on things like mouse embryos And so we're gonna we're gonna go ahead and we're gonna go through this a little bit And this is the very early stage, but it's very similar to the way that the human You know embryo develops and what you see is you'll initially see the outpouching of the optic vesicle Okay, Chris. What is the what layer of the? Embryological issue does the optic vesicle come from Neurotic to do very good. So again now we're gonna practice Answers here for oral boards and so two things that you don't want to do if you ever want to get credit for answering a question Don't go and Then don't let your voice come up So don't go to do because then the attending things you're guessing you'll get no credit for it Even if you get it right so no matter if you're right or wrong say it with conviction No right to do and so then if you got it right great if you got it wrong you still get partial credit So basically when the embryo forms the eye you have an outpouching from the neural ectoderm Which comes out toward the side. It's called the optic vesicle and In schematic form on top and then in actual cells again from mouse embryos on the bottom You can see that the optic vesicle pouches out its neural ectoderm And then it approaches the surface so Rachel. What is the surface? What layer is the surface made of? Surface ectoderm alright, so as this neural ectoderm pouches out it hits the surface ectoderm The surface ectoderm will thick it and then you'll get an in Pouching and so you'll see you'll get this Starting to go in almost like you've got a balloon that comes out and it's a soft balloon and then you put your fist in it and so what you see is you see that this neural ectoderm will invaginate and Surface ectoderm will invaginate also and then eventually the surface ectoderm will pinch off and will form the primitive lens The neural ectoderm will go into two layers and those two layers will form other structures of the eye that we're going to talk about Okay, you can see it again in The mouse embryos we're looking down here. So the surface ectoderm is here it thickens It will begin to invaginate and so you're left with a bilayer neural ectoderm Surface ectoderm will pinch off and will form the crystalline lens all right, so When you look at what the neural ectoderm does the neural ectoderm once it invaginates in it's got two layers So vice what are those two layers end up forming the epithelium of the ciliary body as well as the iranum Okay, and what else? Besides ciliary body iris Also, so the iris pigmented epithelium the ciliary body epithelium both pigmented and non pigmented And then the RPE and the retina all comes from the neural ectoderm So if you look at it as you go further back the RPE is that outer layer the entire retina Comes from the inner layer and so all of that inner layer You know comes from that comes from that single layer So the retina all the layers of the retina that you think about come from that inner layer of neural ectoderm all right now How does the blood supply get to the you know developing eye? And that's an important thing that we need to look at and so What you've got right here is you get a little fissure That is Inferior a little bit inferior nasal and in that fissure will travel the hyalurid artery And so the hyalurid artery will go into that fissure and eventually the hyalurid artery will Go ahead and give blood supply to that inside of the eye as it is developing And so when you look at this you can see that it'll come in through this little fissure and then eventually that fissure will close So I'm going to show you a couple things that happens when that coral fissure doesn't close So what are we looking at right here? All right, so this is an iris coloboma and you notice that it's inferior So when that caroidal fissure where the hyalurid artery comes in closes it first closes about at the equator And then it runs anterior and posterior So if you're going to get a failure of closure You're going to get a coloboma and so most commonly the colobomas are either anterior posterior They're not usually in the middle because that's where it begins to close off And so you see an iris coloboma here inferiorly and that is a sign that that Caroidal fissure did not completely close off anteriorly If you look posteriorly, what do we get? What do we get here? So this is a optic nerve coloboma All right, so you can see posteriorly and again, it's inferior. What are that fissures? So here's the optic nerve and you're just looking at bear sclera here So it didn't close off completely is you didn't get retina to form you didn't get RPE to form and so posteriorly You see an optic nerve coloboma. Those are the two areas where that caroidal fissure just doesn't form All right, so we talked a little bit about how the lens forms and the lens again comes from the Surface ectoderm and so the surface ectoderm will Invaginate it'll pinch off and you'll get this little round cysts now these fibers posteriorly will start to grow and they'll grow Anteriorly and they'll fill that vesicle completely until it becomes solid and that's your embryologic nucleus of the eye now after that From then on you do not normally have lens epithelial cells posteriorly They'll go to the equator and then they'll send fibers anteriorly and posteriorly throughout life And so your lens will become bigger. It'll become more oblong shaved It'll become denser, but you normally do not have lens epithelial cells along the back surface of the crystalline lens And this just shows a little bit how these fibers come They come from anteriorly to the equator and then they fan out Along the equator and they send fibers anteriorly and posteriorly and here it is on the CM Fibers going anteriorly and posteriorly, but you do not normally have lens epithelial cells posteriorly After those first, you know eight weeks of the embryo developing here. You see it in the mouse eye again Very similar to human eye again embryos Look look very similar when you're looking at this stage and here you could actually see it in the eye now Here is that high-loid artery and that high-loid artery will provide vessels To the forming lens, but also to the iris and to the anterior Segment of the eye and so as that high-loid artery, you know helps that developing eye go Eventually that high-loid artery will regress and it will go down normally However, there are times when the high-loid artery doesn't go down. What do we see in here? It's actually called it's just called a persistent high-loid artery And you can see this not uncommonly every once in a while you'll be looking in you know with your 90 and you'll look it and you'll say What is that funny line right there? And as you look you'll see here's the tunicovascular salantis, which you know should eventually go away And here's that high-loid artery coming all the way back and inserting into the optic nerve So sometimes you do not get complete regression of that high-loid artery And you'll have remnants both anteriorly and posteriorly once again So here you see this is an eye. This is about 25 weeks gestation and this just shows you Here's your tunicovascular salantis. Here's your lens And behind it here is this little vascular network. It's like a net of vessels all around All right now we want to talk a little bit about just pathology in general and again This is just an intro lecture and so I want to talk about some of the cells that we want to look at And some of the inflammatory processes that we have to deal with so this is a fake slide I mean I copied it. You don't get a slide that's got every single white blood cell on it But I thought it was a cool slide. This has been passed down for probably 40 years But it's got kind of a picture of all the different types of blood cells on a single slide So let's just keep going around What is this cell right here? It's like a P. M. N. P. M. N. And what does that stand for? polymorphic nucleus polymorphal neutrophils so we've got multiple nuclei In here you've got all these little secretory granules in here. So that's a P. M. N. All right, what's that one? That is an eosinophil and eosinophils are pink They're eosinophil-extaining and they'll often have a bilobed heart-shaped nucleus And you've got all these little eosinophil granules. So by the way, I just ask questions of everybody So if you're just here, that's okay. You don't and you don't have points taken off All right, so that's an eosinophil All right, now we're going to look at a different type. What is this thing? We'll just keep going around So that one was pink eosinophil. This is blue That's a basophil All right, so it's a basophil and you can see that it's got blue granules all over the place. All right, what is this? More specific not quite Moral lymphocyte, but still same idea. So it's a mononuclear cell. It's a lymphocyte What are these things? Believe it or not, those are platelets And then here we've got of course red blood cells which kind of give you an idea of the sizing Of these various white cells All right, so let's talk a little bit about each one. So PMNs, okay Again that polymorpho neutrophil it can have anywhere from three to four even up to seven little nuclear fragments. What does a PMN do? So it's uh, it's crits granules. Uh, it's kind of all that our first line immune system Exactly. So it's kind of the first line defense that you have and so each of these secretory granules has Collagenases in it. It's got proteases in it. I mean, this is the real defender And so when you have an insult these are the ones that go in they release these granules these granules help to You know kill whatever invading pathogen is there. They help to eat up Whatever is there now this is good because it helps your body Defend it now if you're in a cornea You know your clear cornea stroma, this is bad because you don't want You know all this stuff being dumped out into your cornea And so you know again, it's a double-edged sword when you're looking at your your inflammation. So PMNs are kind of your front line I'm inflammatory mediator cells All right, what do we asynophils do? They also have granules and they're Associated with Exactly. So a couple of different things if you see parasites that are inside the eye You'll often see these asynophils associated with them But they're often involved in our allergic reaction and a lot of the granules they release have things like histamines and other things in them So they can be involved in allergic type of reaction. So again Um, you know, the immune system is always a balance. You want them to be acting to protect you But you want them to shut off before the actual inflammatory reaction causes more damage or causes more symptoms and more problems And this just shows you why that's a bad picture of you asynophils. Sorry about that All right. So what do lymphocytes do? So they're involved in So they're more chronic inflammation. So you see these modern nuclear inflammatory cells, they're more Chronic inflammation and again viral sometimes viral And so this is a lymphocyte when you look at the lymphocyte The nucleus takes up about 90 of the cell body and then the site of plasma is just that little sliver around it But in addition to, you know, just standard lymphocytes you have plasma cells and what do plasma cells do? All right, so they're basically an antibody factory If you look at them and so when you look at at plasma cells, the nucleus will be eccentric And so it'll be pushed to the side and then you see the side of plasma here You often have what we call a wagon wheel clumping. It looks like one of those You know wagon wheels that you see on the, you know wagons that the pioneers brought across the prairies And so here you see the wagon wheel clumping and then you'll even see a little area here where it's kind of clear And that's where all the Golgi apparatus is sit and that's where the antibodies are made And so these if you think about it are almost an antibody factory And they come from the B lymphocytes and then eventually We'll transform into the into the plasma cells now Eventually when you have a really chronic inflammation going on these cells that are making all these antibodies can eventually Almost overproduce and it ends up spitting the nucleus out And just leaving you with a big sack of antibodies. And so these are called Russell bodies So that's a sign of chronicity of of an inflammation Okay, now Monocytes what do monocytes do and why are they important? So there's another cell that's involved in kind of chronic inflammation And when they go into the tissue, they turn into a macrophage And that's what's important So the monocytes as they leave the blood vessel and go into the tissue transform into macrophages And once they're in the tissue as macrophages or if you want to sound intelligent Say something with the british accent. So you say macrophages And so that makes you sound more intelligent macrophages so Um, and I couldn't do a lecture without insulting somebody. So if you any of you guys are from the south, you know I get to insult you so no matter what you say with the british accent It sounds intelligent no matter how smart you are if you put a y'all in there It just don't sound smart, you know, so or if you're from Wyoming, you know, it's really hard to sound smart So but if you want to sound intelligent and you want if people think wow that guy's really smart Say it with a british accent. So say macrophages And then it sounds very intelligent. So what do they do? Um So their main role is actually for presenting antigens to Uh different Other different white blood cells exactly so they kind of gather these different antigens and present it But they've also got another function. They're kind of the the garbage man, you know the immune system And so whenever you have an insult, they're the ones who kind of clean up Clean up the damage that's being done too. And so they do have kind of a You know, they'll phagocetize sometimes and they'll they'll help to kind of clean up some of the damage also And these as you see now these are macrophages that have now gone out into the tissue And so you can see the macrophages that excuse me the macrophages that are there Okay, now Eventually these macrophages can transform themselves into what we call epithelioid cells and these epithelioid cells can even Um be further placed along where they start to form multinucleated giant cells So when we want to look at Giant cells we're talking about granulomatous inflammation and when we're talking about granulomatous inflammation I want you to remember the rule of threes And so the first thing is there are three different types of giant cells But there's also three different types of granulomatous inflammation. So remember the rules of threes So the first type of giant cell we call a langhans type giant cell. What does that do? All right, that's associated with what you think about as a granulomatous inflammation So that's your standard run-of-the-mill granulomatous inflammation has these langhans type giant cells So they're like shaped like a horseshoe or a circle and you see the nuclei will line up around the outside There'll be this common cytoplasm in the middle and these are what you think of as just regular run-of-the-mill giant cells And these are what they look like you've got these cells here around the periphery So this is what you think of as associated with a run-of-the-mill granulomatous inflammation All right, how are these different? Uh, these the the nuclei aren't arranged in the periphery. They're more mid periphery I think so they're more jumbled here. So they're more jumbled and we call these form body giant cells and so in the eye when you usually see these is If you've had for example, someone had a branch, you know, poke them in the orbit or poke them in the eye You may have this but the other thing is is around sutures You'll get a form body giant cell reaction So when you look at a suture that's inside the eye, you can see a form body giant cell reaction These have the nuclei throughout the cell itself clumped together instead of lining up around the periphery So they're called the form body giant cells And here you have believe it or not, this is what's left of a nylon suture here And here you have a form body giant cell sitting around it So you can even get a form body reaction around a suture And the third type of giant cell boy You guys get passes here Tutan giant cell and what is a tutan giant cell? So they have the like a ring of nuclei, but it's a little more centered and there's a clear site of plasma in the middle And then the foamy vacuoles outside All right, so you see these are around the nuclei line up, but you see this empty vaculated space And what is that vaculated space filled with? It's actually lipid Yeah, so when we process tissue When you know when my technician processes just a normal tissue and you put a formula and they process it It goes through several steps including Dehydration steps. And so what happens is during routine tissue processing lipid dissolves And so it leaves this little empty white foamy looking appearance to it So when you see these empty white spaces around here, that's actually lipid So these are the so-called tutan to you to and tutan giant cells Good evening. Good evening Sorry, I can't resist that I've got to get some reading glasses My old department chair when you were late for lecture He had these reading glasses at the end of his nose and he'd peer over them. He'd go You got to get some reading glasses. I can just peer at him So tutan giant cells, what are they characteristic of there's a couple of things you need? Juveniles anthogranuloma Juveniles anthogranuloma as you see these in kids And so these would be kids They'll have these really weird looking lesions on their iris and they'll get these spontaneous hyphemus And so you can get them in juveniles anthogranulomans when you see these and so Langhans giant cells Form body giant cells tutan giant cells three different kinds of giant cells Now you've also got three different kinds of Of inflammation involving And so the first type is called sympathetic ophthalmia. What is sympathetic ophthalmia? Yeah, this is a historical thing really hopefully we don't see this often so it's when you have an eye that's Injured and has that inflammatory response the other eye the fellow I can also have that same response and it's thought to be in reaction to some of the Pigments and other things like uveal Uh antigens that are released after that injury So people have argued about this for many many years You'll get a severe injury And your immune system will get really stimulated and you end up getting an immune reaction even in the other eye These were especially devastating during the first world war which ended 100 years ago last month And people would get these horrible injuries in one eye And then you know two weeks later the good eye would start to get Inflamed and inflamed and eventually they'd lose the good eye So they'd go by that early blind from this and so it was sympathetic meaning you'd get a sympathetic reaction in the opposite eye So it's an immune reaction nowadays. We have cortical steroids. This is why when you have a severely injured eye You know, you you either fix it or remove it within 10 to 14 days. You don't let it sit there forever now Again, we can treat sympathetic ophthalmia. Now. It's really rare. I think I've seen You know one or two cases in 30 years now. So it's very rare, but it character it's characterized The diffuse type of granulomus inflammation. So when you actually see sympathetic ophthalmia You see this diffuse granulomus inflammation involving the coroi Now it's interesting about this is it tends to spare the coriocapillaris And that's a way you can differentiate this from other forms of of diffuse granulomus inflammation All right, now there's a second type of granulomus inflammation where you get these focal nodules What do you think that one would be what do we call that one? What kind of a granulomus inflammation we have around the eye? We it's actually sarcoid So this is actually called sarcoidal So when you see this kind of a nodular Granulomus inflammation, it's called a sarcoidal Inflammation and what's interesting? Look at that giant song. I mean that thing is huge And so you get that's a really big giant song And you can get these interesting they call them asteroid bodies in here I don't know some people think that looks like an asteroid. I think it kind of looks like a I don't know a meba or octopus or something, but they call them asteroid bodies And so the second type of granulomus inflammation is a nodular type multi nodules And it is called sarcoidal Now there's a third type where you can get a more zonal Granulomus inflammation and what you think about with the zonal granulomus inflammation Take a stab there Okay, so this is is if you have a rupture of the lens capsule Or you end up, you know, either dramatically or you do a really bad surgery and you leave a lot of cortex in there You can actually get a zonal Inflammatory reaction around that they used to call this Facoanophilactic end up the mitis. This is one of the two double misnomers you have to memorize It's not anaphylactic and it's not infectious But it's a ruptured lens capsule or a lens capsule with with really really bad surgery Causing a zonal inflammation around it And here's an example. This was a Wyoming rancher who got kicked in the head by his horse trying to put it in the trailer and so Ended up with this really nasty injury to his globe. This is a ruptured lens. Believe it or not That's what's left of the cornea. There was a little bit of ciliary body up here And so you get this zonal Granulomidus inflammation around that so that's three types of giant cells three types of granulomidus inflammation Now we we don't really have a place to put this in so I want to Put this in right here just for lack of a better place to put it in the lectures Bish, what's different about this globe? It's disorganized Disorganized It is definitely smaller than you would expect Small what do you make of the shape? Shape and it's more like square Square instead around the thickness of the sclera very thick really thick. What do you think this would be? So tisus bull by spelled with a ph th Tisus bull by And so this is an end stage reaction to an eye to Either severe inflammation a severe injury Anything like that, but this is an end stage and so once an eye Shuts down it becomes tisical. So the eye becomes smaller it shrinks. It becomes hypotenuse the pressure will go down to zero It's more square than round the sclera gets real thick the chloride gets thick you have disorganization of intraocular contents So here you can see it look at that eye. It's almost square rather than round. Look how thick the sclera is Look how thick The core is it's spongy and very much edematous and you've got disorganization of intraocular contents There's the thickened sclera There's the spongy thickening that you see of the core, right? What is this stuff? All right, let's go closer and indeed It's bone and so interestingly enough with end stage tisus bull by you can get bony formation Inside the eye. Where do the you know what cells form bone? RPE exactly so rpe is a very pluripotential type of cell And so when you stimulate it, you know in any way it can lay down gliotic tissue It can even lay down bone And so in an end stage tisical eye you'll literally see bone Inside the eye so my technician has a heck of a time cutting me. She goes to cut him and literally hits bone And so I just didn't know where else to put in tisus bull by so we kind of put it in here because it is An end stage of how the eye reacts to either chronic inflammation or chronic trauma All right now. I want to talk a little bit here. This is where I make my plea to you guys because you guys are going to be in surgery eventually When we get Specimens from the or the more information that we have from the surgeon the better we can treat that specimen And so communication is the key and plan ahead of time You don't know how many times we get a call from the or Oh, dr. So-and-so wants you to do this with the specimen and we're like Well, wait a minute. It has to be fresh or it has to be in this special fixity. It has to be in that And instead they just plop it a formal line or sometimes they don't even call we get it down in the lab Do this rule out that that doesn't help us at all because by then it's often too late So if you have a special circumstance or you want a special stain You want us to do something different with the specimen call us ahead of time And so you call me call the lab the fellows are down there You really got to communicate if you want something done specially Because if not if we don't know what you want done, we can't do it for you So, you know simple phone call is is really critical And i'm telling you guys because if you're in with dr. Crandall and he's doing 14 cases in a day He's not going to have time to do any of this. It's up to you guys and so But eventually when you're out in practice and say you decide you're not going to do a fellowship And you're going to go out and practice in oral, you know, you want to send me a specimen call And just let us know ahead of time if you want something special. So communication is important So we get a requisition sheet. You don't know how many times we get a requisition sheet with no history So, how do I know what you want done with it when it says cornea? Okay, cornea. I don't know. Is it an ulcer? Do you want special stains? Is it a dystrophy? You know, are you looking for an acanthomoeba? I don't know that so then my technician process that then we're looking at the slides and we go Oh, was it this was it that then we have to pull out the computer try to look up the op note Or look up the clinic notes and so if you You know are going to be in there fill out that form it only takes a sentence You know herpes zoster rule out this or you know this rule out that give us information And fill out the requisition sheet now if you're worried about a tumor somewhere A drawing is really nice. And so booby does these all the time. It's wonderful He'll put a little drawing. He'll say you'll say nick You know chop comes in with this specimen and and we want to look for this Ta booby and so you know you want to be able to align it so my technician can tell okay You're worried about the nasal border the temporal border draw a picture Now handling of the tissue is important and again, we don't talk about this very much If you grab a tissue with the forcep and really crunch it you crush it And crush artifact makes it difficult for us to know what the pathology is And so be very gentle when you're grabbing that tissue be very careful Now if you've got a potential tumor or something necrotic, don't just submit that Submit some normal tissue around it so we can look at that also and that's very helpful to us Fixate it promptly. I mean have the nurse put it into the formalin right away Now what do we normally fix it with 10% neutral buffered formalin is good for almost anything Even if we're doing the immunoperoxidase stains nowadays formalin is tissue is okay If you're going to do em now, that's really rare that we do em anymore But you want to have a gluteraldehyde base fixative If you want frozen sections or special stain for example to look for lipid that tissue has to be fresh And so the important thing is is when you do fresh tissue Don't just put it in the jar dry because it'll dry out Don't drop it in bss because it'll get Maserated take a saline soaked gauze soak the gauze in bss Put the tissue on the gauze then put that in the container and call us immediately We don't want to let that sit overnight and not be fixed and we can go ahead and freeze it and fix it So let us know if you're out in the community You can actually take a specimen put it on the little saline soaked gauze Close it put it in one of those little Insulated chest just put ice in it and it'll keep for 24 hours. You can fat exit to us And so that'll keep it just regular ice doesn't even have to be dry ice just regular ice will keep it for 24 hours Now conch is different Because if you do conching tibia you take it off. What is conch do it curls up in a ball? So if you're looking at a trigem, that's okay. That doesn't matter But if you're looking at say, you know, you're worried about pathology in conching tibia You don't want it to roll up in a ball And so the idea is you want to lay it out And what I found best is you know when you Spin your gown around there's that little piece of cardboard that you've got The under surface of that is kind of a rough cardboard. That's perfect to put conch on And so what you want to do is is when you spin your gown take that cut a little two by two centimeter piece on it Lay the conching tibia on that little piece of cardboard Let it sit for about a minute and then float the whole cardboard and four on And that'll actually stick to it and my technician can process the whole specimen Well, it's laid out like that and um get the margins And so the problem is is is how do we tell margins? We've had people put pins in them Pins come out They don't do anything regular ink You put ink on there the ink dissolves from the formalin. So that doesn't work either You can put a suture in the end of a specimen and that'll help mark it But the other a nice way to do it is put a notch in there. So here's our piece of cardboard Here's our conch nicely laid out till it sticks. Okay, notch is temporal Cut a notch in the tissue in the Cardboard in the notch we can mark the notches temporal two notches are superior Draw us a picture again 30 seconds to do this and we can align your specimen exactly and tell you what the margins are So conches is the way we do this, you know, if you've got eyelid or cheek or something That's a different matter and that you can even put in a little suture or something like that Okay questions on that Very good Okay, I want to talk one last last little part here about stains Because we use several different stains and ophthalmology and ophthalmic pathology and it's important that I think you understand What various stains do? Boy, where did we stop? Yeah, I think we stopped at you. What's our standard stain? What's the stain we use the most often? Um, this is h&e and what does h&e stand for? Well, at least you got h&e you get credit. It's a hematoxilin hematoxilin Eosin so the hematoxilin is the blue part of the stain the eosin is the red part of the stain So that's just our standard stain here. We're looking at a cornea. You can see it stains the epithelium Epithelium is the common stains of palmatory cells blood vessels. This is the stain we use, you know, 98% of the time I mean just a standard h&e stain. So we do that routinely Now there's another stain that we use probably the second most common. What do you think this stain would be? No, not quite Look and see what is it staining. So we're looking at the cornea here There's the corneal epithelium That little line of magenta staining there. What part of the corneal epithelium is that? Basement membrane. Basement membrane. So what stain stains for basement membranes? PAS. PAS again if you sit written down you say what? Periodic acid shifts. So that's why we say PAS. It's easier to say PAS stains basement membranes that nice bright magenta color And so things like epithelial basement membrane if you want to look at basement membranes You do a PAS stain. So it's a basement membrane stain All right. Now there is There are several stains that we use For corneal dystrophies and when we get to the corneal section, we'll memorize the mnemonic to do that But there's a couple of different stains that we can use that stain different material that can be involved in corneal stromal dystrophies What do you think this stain would be here like? Oh Is this Is the halcyon blue? This is halcyon blue exactly. And so what is halcyon blue stain? Um All right, we might as well do the mnemonic now because you guys are just saying what is he talking about? So for corneal stromal dystrophies, there is a mnemonic to to memorize Marilyn Monroe Really always gets her man in la california Okay, don't ask but that's the mind that's been around since I was a resident. So since the ancient times All right, so Marilyn mucopoly saccharide Monroe I'm sorry, Marilyn macular dystrophy Monroe mucopoly saccharide Really recessive a Alcien blue All right, so mucopoly saccharide Alcien blue so alcien blue stains from mucopoly saccharide. All right, you get you guys get a pass Gets What's that? Ah a good guess, but not quite gets his granular her Highland man either Mason's trichrome Okay, so this is a trichrome stain And so granular Highland and so it stains highland. It's a mason's trichrome stain and it stains highland And then last l Lattice Lattice a Amaloid california congo red. So amaloid Is in lattice dystrophy and it stains with congo red. So this is a congo red stain again. It's not really red I think it's more burnt orange, but that's just me but not really bad. We're kind of long horns, you know burnt red It's just long horns. Okay, so that's amaloid and what is it? What am I showing here that amaloid that that does when you do a congo red stain that looks cool into the microscope? Biorefringence, so if you put polarized filters on there two of them and you cross them You get biorefringence and the amaloid lights up on the specimen. It just you know looks cool when you do it So those are those are some of the stains you do so memorize that mnemonic for the cornea session we'll talk a little bit more about each of these but Again, this is now most commonly seen in lattice dystrophy Amaloid is the material congo red is the stain Okay, now we've I guess we've come back around now. There are other stains we can do what what kind of stain is this? Yeah, what's the stain for fungi? Anybody? GMS okay, so gms stands for Gamori methenamine silver And so the way you remember that it kind of stains the the fungi kind of a silvery black color And so here you can see the little hyphae And so gms is a stain that we use when we're looking for fungi And again, if you have a corneal ulcer and you're sending us a corneal button it you're worried about Fungal ulcer put you know rule out fungi and then my tech will know ahead of time She'll stain it with gms and we'll look for fungi Okay Kind of stain is this richo So these are like those cysts that you can look for it exists in the corneal. What do you think these guys could be? Exactly. So this is a stain that stains for acanthamoeba And again bonus points for what stain this is Hard to remember anybody Gridley, okay, and and I just like this gridly I don't know I for some reason gridly sounds like you know the butler and an english, you know tv show You know gridly bring tea, you know, so yes, uh So gridly stains stains for acanthamoeba and so it'll stain The cyst this kind of again kind of a silvery color. It'll stain the background Um stroma of the cornea green. So that's how you know it was a well-done stains gridly stain All right, and this is kind of a different stain Vyche Heck is this Russian bluestain and what is prussian bluestain? Iron so it's a specialized iron stain. So here you see a cornea We've got some iron in the epithetism So there's a whole bunch of iron lines that form in the cornea and if we stain them we can stain a mirror How do we remember prussian blue and iron? Yeah, it's a hundred years since the first world war ended all right So who are the prussians the prussians were the militarists in the eastern part of Germany who really led to the rise of germany and really led to the aggression that eventually became world war one And so prussian blue stains iron iron makes tanks makes cannons makes you know gels so iron So prussian blue stains iron and that's how you remember it All right boy. This is a different one That's right All right, so this is easy to remember because it's called the oil red o So it stains oil Red and you've got these little o's of oil here. So oil red. Oh, it's easier to remember now What do you have to do special with the tissue to do this stain? That's to be fresh because remember our standard processing dissolves lipid And so if you want to do a stain looking for any kind of lipid Then you have to have fresh tissue. We freeze it. We cut it. So this is oil red. Oh, it stains oil red So these little o's will stain red. So that's how you remember it oil red. Oh for lip All right, so we're going to go next week. This is a little church. It's very interesting. This is a tiny little church And again right off the main Pedestrian walkway in vienna. It is spectacular inside. So we're going to visit that next week. So read the section on lip lip pathology and your bcsc And what we're going to do is we're going to talk about eyelid lesions, you know start to finish next week Questions we have five minutes. All right, great. So again, that's kind of the the Framework for how we're going to do these lectures and so we're going to look at each area It'll be lit next week. It's going to be conch the week after that and then in january again We do cornea, then we'll do you know expecting a mesh work glaucoma lens iol's retina optic nerve orbit tumors And so that'll be the order. So just look and see next week's lid. So read your bcs You know, but it's really a nice summary in there. It's nicely done. It's not very long And so just read that over and that'll give you a good background for pathology on lids Okay, thanks