 All right, good morning. So everybody excited, bright and eye-wishing tail, ready to learn about how to get nerves. All right, so today we're going back to the Grand Tetons. And so, for those of you, I don't know, I see nice suits here. Who are you guys? Hi, Nathan in there. For the path? Ah, welcome. Where people wear a suit if it's more than one suit. I thought we were going to upgrade it. The shame of these guys is that they show up with at least a tie on or something. All right, so what we do is I've got a captive audience here, so I get to show people my travel fly. This is always fun for me and not for you guys. And so this is the brain trust for the Astros cataract clinical committee meeting. And so we had a meeting in Jackson. And so we showed up the first morning now. This is not planned, but you can see how great minds think alike. So this is the uniform for the cataract clinical committee from Astros. And so we got to take a picture of this because we all showed up wearing the same thing. So what was fun was that as part of this retreat, you know, we get to do some fun stuff in the afternoon. And so there's a, it's called the Teton Raptor Center. And basically these guys have domesticated raptors. So they bring them around so you can look at them. So this is a peregrine falcon, which, you know, is a pretty good predator. Then they brought a golden eagle. And so if you look at these guys, you know, their wings are tucked in, but they've got about a five-foot wingspan and some serious claws. And I mean, there's just some serious, serious raptors. And so the fun thing is, is they got them there and the people from the center, of course you give them a donation, of course, but they will come and they'll talk about what they do and how they rescue these birds and try to eventually rehabilitate them and train them and go back to the wild. And so if you look at them, it's a pretty majestic looking bird right there. And so they're all over around the Grand Teton. You'll see falcons, you'll see eagles, both bald and golden. So I thought I'd just show you guys some of these guys. It's very rare you get to set a foot away from a golden eagle. All right, so today we're going to talk about optic nerve. So this is what the optic nerve looks like as we're looking in. And you can see the nice, sharp edge, non-elevated, non-congested, reasonable color. As you're looking in, vessels, arteries coming out, vinyls going in. Okay, let's start with Ashley. Ashley, what stigma are we using here? A tricol. And how can you say it's a tricol? I don't think my way is the best way but just because of the colors. Well, exactly. So what do you remember now? Now the third color for tricol never shows up in any of these pictures. But in any event, it stains connected tissue blue and it stains tranquil tissue red or pink. So if you look, here's the optic nerve itself. And then it's got the connected tissue around it that is stained this blue color. Okay? So my analogy to the optic nerve is that I think of the optic nerve as a fiber optic cable. And so each axon, as it leaves that ganglion cell, goes through the laminar fibrosis and then out into the optic nerve. And once it gets posterior to the laminar fibrosis, it becomes myelinated. So it's a single fiber optic cable and it's got a little plastic around it. It's got myelin around it. Then these columns of axons, they form bundles with these little piocepti in between them. And those are the fiber optic bundles that you see when the fiber optic cable is there. Then the whole thing is shoved into the ground, but you can't put those fiber optic cables in the ground. So you have to put a steel cable around it, a steel round tube around it, and that's the optic nerve sheet. And so if you think of it as like a fiber optic cable in the ground, that's how you can remember it. So each axon is myelinated just posterior to laminar fibrosis. The levels of axons have these little piocepti in between them, and then the whole thing is surrounded by the optic nerve. So here we see, I'm not going to get a better picture than that. It's like 30 years old now. I'll take it. And remind me guys, when you get a retinoblastoma, you know with a good optic nerve, I'm going to take a better picture. But here's the optic nerve sheet. And so remember, this is the second cranial nerve. And so it's got similar surroundings to the brain hands. So you've got the dural sheath around it, the optic nerve sheet. And then you've got the arachnoid granulation, subarachnoid space, and then the pia mater, forming these little individual columns. Okay, Becca, what are these two structures? Central retinal artery. Exactly. So if you remember from last week, central retinal artery and vein, they share this common adventitial sheath. So thickening of that artery, arterial sclerosis, actually pushes on the vein next to it and can cause vein occlusion. And here's a close-up. This is the optic nerve sheet. These are these arachnoid granulations, subarachnoid space. And then lastly here are the individual axons with these little piocepts in between. And here you can see the longitudinal. Okay, now there are some cells that live in between these columns here. But you see the little blue cell bodies. So Jason, what are some of the cells that live in there? There's... Okay, well, in the piocepts, they're mostly on the outside. They're more in that subarachnoid or arachnoid space. So they don't usually live inside the prank of that cell. What are the cells that produce the myelin? So the libidendrocyte. The libidendrocyte. So that myelin's got to come from somewhere. So some of these blue nuclei are a libidendrocyte. But there are also astrocytes that live in there. And that's important because you look at what tumors can affect the nerve. You don't get tumors of the nerve itself. You get tumors of the cells that are in the nerve. And so you get libidendrocyte. You get astrocytes that live in there. And here we can see again, central retinal artery. Central retinal vein. You're there apart. And then as you get closer and closer, the optic nerve can eventually come together. All right, so Chris, what are we seeing here? A funnest photo of the right eye with some kind of myopic changes around the optic nerve. Tilted disc. You look closer. So first glance you may say that's a myopic change, but I would say it's a little bit different than that. You definitely got this crescent of white around it. Right. I mean it looks like it, from the photo looks like a tilted disc, but I know that you're trying to lead me to something else. Here's the outline of the disc itself. Right. So that's actually a very small disc. Yeah, it's a hypoplastic disc. Exactly. This is a hypoplastic disc. So the way you tell us apart, myopic discs are big. Right. You still have that temporal crescent, but myopic discs are large. They're not small. They're larger discs. Whereas if you look right here, you can see this is a small disc, but this is a hypoplastic disc. It's kind of the opposite. Right. So what do you worry about in these patients? So cranial nerve, I mean not cranial nerve, central nerve or central nervous system abnormalities, mainly central or midline abnormalities. Okay. And if this is inherited, how is it inherited? Usually autosomal dominant. Exactly. So autosomal dominant. So it's interesting. I saw a teenager was referring in my outside of town, which is for funny looking discs. And we looked in there, hypoplastic discs. And so we asked the mom, do you mind if I take a look at you and turn up mommy Alan too? Oftentimes though, if these are just isolated to the eye, they do not cause problems. And so they're really not, and really these are more at risk for like, just giving up your ophthalmology, as far as I know. And so oftentimes these are just benign looking discs, but this is a hypoplastic optic disc. Okay. Tara, what do we see in here? This is what is below the right eye. I think that maybe like an optic nerve coloboma. Exactly. What does coloboma mean? Anybody? A failure of fusion of the embryonic tissue. It is, but... Oh, there's a Greek. Somebody look it up. Of course. What languages have come from? Okay. Maybe Greek or something. From the Greeks. So look it up. Coloboma. Look it up. Look it up. So. But exactly. This is indeed an optic nerve coloboma. So Eileen was onto something. Look at the location where it is. So it's usually these colobomas are inferior. So, Tara, why would an optic nerve coloboma be inferior? Because of the formation of the embryologically. That's where it failed to form. Okay. So how does that happen? What happens embryologically that allows these colobomas to form here inferiorly at the optic nerve? I'm not sure. Okay. So remember when that optic vesicle, it poaches out from the primitive neuroactoderm and then it imaginates. Well, on the inferior part, those vessels, those hyaluronic vessels come in and feed that as it's growing. But when it starts to seal off, that globe will seal at the equator. And then it'll be like a zipper that you're going both directions. So start from the equator and go back to the optic nerve and anterior to the iris. So when you get a defect in the closure of that fissure, that's when you get a coloboma. And so, optic nerve is the posterior part of that fissure. So you get an optic nerve coloboma. The anterior component of that would be what? Something on the lens council. Even more anterior than that? The other iris. Exactly. So those iris colobomas are the same thing. They're inferiorly there and they're kind of the anterior most location of that in rheologic fissure that's not fusing. Now, this is the ultimate kind of coloboma I call it. I named, what does this one call? This is named. This has got this name to it. It's like a giant optic nerve coloboma. This is named after the flower, the morning glory. And so if you think of it, morning glory flower, it's like a trumpet horn. Okay, did we find coloboma? I had a question. Yes. So the difference between optic nerve and coloboma and pathologic? We're getting to that. Yes, hold that question. But it's highly debated. Some people think that they're related and some people think that they aren't. Exactly. And they're still debating on exactly what leaks out from a coloboma, too. So that's where we're coming to that. So this is a morning glory flower and if you think of it, it looks like a trumpet horn. And so when you go back to that optic nerve morning glory syndrome, it's like the ultimate coloboma. It's like you don't get any of the posterior part forming properly, but not only that, but it's almost like there's this trumpet horn going away from you. So when you look in there, you see that this is in focus here, but this is all blurry because that's actually moving away from you. This is called a morning glory syndrome. You see that there's very little, you know, active fibers going in there. So you get a significant visual loss from these morning glory anomalies. All right, speaking of which, we're going to skip to Rhys. So Rhys, what are we looking at right here? Optic nerve pit. Exactly. There it is. And so I'd like to show you guys the obvious. I probably shouldn't do that because that's so obvious even these guys interviewing me. Well, maybe they wouldn't work, but you never know. But this is an optic nerve pit and so it's pretty obvious here. You know, maybe one of the interns could pick it up. I would figure that out. But this is an optic nerve pit and what's the biggest problem with an optic nerve pit in terms of vision? Distant attachments. And how do they occur? I mean, so you did an indentation of the retina into that pit and then it just comes up right over that. All right, so indeed, here is an optic nerve pit. There's optic nerve pit and you see part of the retina almost dipping into that, but the reason that people have this vision is you actually get fluid leaking under the retina. And so some people would argue, they'll say it's CSF fluid leaking. Other people say, no, it's something different and they talk about how you're out of gas and there's a big argument about exactly what happens. But bottom line is when you get an optic nerve pit you can get leakage of fluid from the optic nerve under the retina to the macula. So if you think about that, how do you usually get rid of that? Well, you could laser up it. You know, if you laser that bundle, that bundle coming from the macula, the optic nerve, you're going to kill it. And so it's going to be, you guys are way too young, but in your history books, which I don't teach you anymore, there was this war called Vietnam. And in Vietnam, these generals would get up there and they would say, well, we bomb the village to save it. So you get these Viet Cong and infiltrate into the village. So what would the U.S. do? They bomb the hell out of it so they destroy the whole village, but we got rid of the Viet Cong and so it's the same thing here and so if you were to laser that, yeah, you'd get rid of the fluid but you'd kill the retina. And so these are tough to treat. Some people have dug for trectomies and tried to put gas in there and push it back and others have tried to do some light laser in that area, but these are tough to seal off because the fluid leaks out and goes underneath the macula. All right, now we're going to go back. Lee, what are we seeing here? And that's not, you know, a picture that Joa took. I mean, this is actually in focus. Exactly. So you can see that that white in there almost looks like kind of a giant cotton wool spot. That's actually myelination and so remember, those axons normally don't become myelinated until they cross through the lamina fibrosis and so sometimes you can get myelination that jumps the lamina fibrosis and hits the retina. Usually these are congenital and so the optic nerve is interesting. When the nerve grows, the nerve fibers themselves grow from that optic cup back to the chiasm but the myelination goes opposite so the myelination later in embryology comes from the chiasm forward and then it stops at the lamina fibrosis but sometimes it jumps and you get these. Now, do these cause visual problems? They can. Yeah, so you can kind of get an enlargement of the blind spot or maybe a little focal defect because they will, the fibers are still working okay but that myelination will block some of the transmission underneath and much like a giant cotton wool spot would. There's people that increase risk at all of like a, you know, that would come from that. Usually not. Usually it's a separate, it's a separate entity so I'm not sure why, you know, just once they jump and start growing they don't have a chance of growing even more but they don't so these people aren't going to increase risk for that. So I'm supposed to say, sorry, to make you say more, Steve, good question. There you go, very good. Sorry, I'm not slipping here. I didn't bring trophies for everybody today. That's a good question. Actually, that's what you say when you don't know the answer to it and you're intended to go, that's a good question. And then if you don't know then you say, why don't you look that out and go back to us? That way you don't have to flip Steve's answer. No, as far as I know that's not related to like, you know, astrocytomas or whatever it is like that. Alright, Nico, what do we see in here? So this is a, so the borders are a little crazy all throughout and then there's like in the center there's like these yellow specks of these, like optic nerve head. Exactly, so you see this bumpiness here and so at first glance and again, you may get these referred in. I've got these referred in from outside ERs before. They said, oh my God, this patient has papillodema because when you first look in there it looks like the optic nerve is swollen. If you look carefully, you'll see there's these little deposits here and these are drusen. Now the tricky ones are when the drusen are buried. So if they're down deep or you can't quite see them, that optic nerve head looks elevated and can you have bilateral drusen? Yeah, and so people look in and they say, oh my God, it's papillodema and this can actually be buried drusen. Now, sometimes, you know, if you look at them, they're pretty blatant here. This is a bilateral drusen but you can see them pretty well here and even here on these different, on these bilateral drusen. So you see the drusen. What are optic nerve drusen comprised of? Calcium. Okay. So there you can see that's a severe one and that's even one with atrophy there and that's just kind of showing you these buried drusen, how they're harder to see. So there's calcium in them and so what does that mean if you were to do a CT scan? Palloidum. Yeah. So look at the drusen right here and so if you were to do a CT scan they light up but what's an easier thing you can do in the clinic besides send them to a CT scan? Exactly. So if you think about how ultrasound works when sound waves hit something thickly calcified they really bounce off hard and so if you put a B scan on these and you find the shadow of the optic nerve you'll see a bright spike right in that area and even if you turn the game down the eye starts to disappear and then there still be that area of the calcification there so you can diagnose these with a B scan. They are even early on and so the ultrasound is a good way if you've got some deep drusen you look in there and you say I think there might be drusen I don't think this is papillodema you can just grab a B scan put it on there and you'll be able to tell if there's any calcium there because if it's truly papillodema there'll be no calcium or no lesions there at all so very important to tell and so you can actually even do it with a CT scan because that's a better one you can see bilateral here bilateral drusen. How come one of those was white? Yeah that was great. Good question I like to show that to Chris Davidson that's funny I never thought of it it's like this one's white and that one's not and it's the same it should be the same scan so I'm not sure maybe it's silicone in there and because it kills that completely that's funny all this time I'm looking at drusen and I never even noticed that Good pick up Is that a squirrel on there too? Yeah Believe it or not these are older people and have you ever seen old people where they've got that calcified place where the muscle inserts anteriorly? Right there See that's where the muscle inserts anteriorly so this is an older person So here you see this is the optic nerve head gross photograph and you see it's in front of the laminar crevrosa but underneath the optic nerve head itself so that's the drusen you can see right here again optic nerve head laminar crevrosa and you see those calcified drusen underneath the fibers coming in now could these cause visual problems? Drusen You can but even more than that they'll often get nerve fiber layer effects sometimes when these nerve fiber layer bundles are coming over the drusen you can actually get the big ones with disruption so Brad Kanz at one time was doing serial visual fields on these patients through the years and I think he did show that as the drusen get bigger and bigger you can get these little focal nerve fiber layer visual defects you can see right here here's some drusen here and drusen here and this nerve is being a little bit more atrophic a little bit more atrophic these are further along Alright what are we seeing right here Chris? This looks like optic nerve head, Eva and I'm glad you said it that way because they love on normal boards to ask you about this and so you'll say papillodema and then the examiner goes like this because by definition what is papillodema? Is it bilateral optic nerve swollen from the cranial pressure? Exactly for pressure increases so you never say papillodema looking at one nerve when you're on normal boards you say this is a swollen optic nerve and then they say what's the differential diagnosis and then you can say well if it's bilateral and the pressure is high it can be papillodema if it's due to congestion you know or something in the nerve itself but if you look you can see that the edges of that nerve are irregular you've got some flame hemorrhages here you've got some dilation of the vein cells so this is classic optic nerve swelling and if it's bilateral there's a pressure we call it papillodema there's a severe one again this would be one you know even a student would recognize something one of the applicants would recognize so definitely papillodema lots of flame hemorrhages elevated disc engorgement of the vessels and so this is what it looks like so remember from a few weeks ago we showed you the glaucoma changes where you get that excavation and that cupping this is the opposite and so when you look at this you actually get swelling here of the nerve so it poaches out from the nerve you have engorgement of the vessels and you've also got hemorrhages on the anterior surface and boy this is dying here wrapping up the new battery here but so you can see hemorrhages on the surface there and so this is optic nerve swelling or papillodema if we're by that on this is actually the laminocrobrosa gets bowed forward so it's almost like that pressure pushes it forward and so you get forward bowing of the laminocrobrosa in this optic nerve swelling alright what are we seeing right here Joe up well if you look right here this is interesting because this is more focal swelling so if you look carefully look at superiorly it looks like that optic nerve is swollen superiorly but inferiorly you know down here it's not quite as swollen up here it's more swollen so what's your differential diagnosis here let's say this is unilateral okay well no but no when you think of a segmental you know optic nerve swelling you want to start looking at broad categories of the etiology so what are a couple of broad categories that could cause this let's take a step back even more how about ischemia alright so when you look at a focal a nerve and there's some focal swelling in that nerve you want to look at various areas you could have ischemia what's that okay no so you want to start to develop a differential diagnosis and that's what's important and when you see focal swelling like this now Ashley let's say this is a 20 year old essentially optic neuritis exactly so you worry about optic neuritis optic neuritis in the acute phase can give you some segmental swelling of the disc it's more posteriorly so you often don't see anything in the disc but if you do you can get some focal swelling there what's another let's say this is a 70 year old AI1 exactly so anterior ischemic optic neuropathy so you want to start thinking of what could happen and so when you're looking at someone and they're young and you've got a little thema here in their eye they say oh my eye suddenly went blurry and it hurts when I move you start thinking of things like optic neuritis if you have a 70 year old male and he's a smoker and he's overweight and he's got high blood pressure medicine he comes in and he says you know I woke up this morning and half my vision is gone then again that could be something like this so this could be an ischemic optic neuropathy AI1 if you're an ischemic optic neuropathy all right Becca what is this we're showing but why would I be showing you this it looks like possibly a climb in there so what are we looking at first I'm guessing it's the central retinal artery so it is it's an artery except we usually don't unless the person dies we don't give pieces of central retinal artery what artery do we actually that's probably the temporal artery exactly this is a temporal artery biopsy seen in cross section why would we be taking the biopsy of the temporal artery if you were concerned for GCA exactly so when you see someone who's got ischemic optic neuropathy one of the things you don't want to miss is you don't want to miss an auretic form now most of the male AI1 are not inflammatory they're not auretic they're you get arteriosclerosis and you get this little posterior ciliary artery just blocking off but you don't want to miss a case of what's called gynecologist or you don't want to miss the cranial lobinus inflammation of those arteries because that can cause people to lose vision in both times and so you'll do a superficial temporal artery biopsy why because you can take that out without harming anything so you're always going to find a case report somewhere where someone's circle of closed off and the superficial temporal artery is feeding it I mean that's like one in several million and so you can pretty much remove these safely without causing any harm and then we can look at it and see if there's any inflammation now do you see inflammation on this one yeah and so we don't see any here and so you look at a temporal artery and cross-section there's the lumen and it's got some red blood cells in here's the intima that actually looks pretty good so this I want this artery right now this guy's not been to crowd burgers or moochies you know he's drumming cheeseburgers and cheese steaks you know and so pretty good looking intima and then this little squiggly line is the internal elastic lamina you see that's completely intact so I like to say what does that look like do you ever see those satellite pictures of the Mississippi River when it's like flooding Iowa every spring and you know it goes back and forth and it's got completely intact and then the adamant tissue around that no inflammatory cells what do we see right here Jason this looks quite alright so we start in the middle what do you make of the lumen it's very narrow very narrow suspicion is severe arteriosclerosis this is lots and lots of cheeseburgers you know and pastrami and all that other good stuff so markedly thickened intima look at the pretty much white you can't even see the muscular media here and then the adamant tissue is surrounded by this cuff of blue so this is a positive temporary biopsy and you can see that when you get this you're at real risk for the arteries completely closing off so you really have to treat these with steroids right away so if you see a patient and there's a high suspicion for temporal arthritis you can set him up for the biopsy but if you wait for the biopsy results and to give him the steroids they can actually lose vision not only in that but in the other eye so start them on steroids now and then do the biopsy within 7 to 10 days and then you'll see if you need to keep them on there my pet peeve is you get the guys you know that are referring from the outside they say oh we think this is temporal arthritis what do they do they give them so then the patient gets a septic necrosis so they're here where they get crazy from the penis and they say well do they still need to be on it so then we do the biopsy and then you see an artery that you say well is it yield-arter arthritis because the inflammation's calm down and you try to figure it out so the key is if you're going to put somebody on steroids maybe for a long time you got to have a diagnosis and so so long as you do the biopsy first because you want to prevent that and what do we look at right here Jason so we see a lot of giant cell giant cell that's the name giant cell arthritis so you can see the giant cell that's there and so you don't have to have giant cells necessarily you can just have lymphocytes maybe some epithelioid cells but it's called giant cell arthritis and here we can see this is that and they ran into complications they want to know is this giant cell arthritis and if you look there's a little bit of thickening of the intima there's a little bit of destruction of the internalized deployment and over here look the muscular media's gone from that area so this is what we call a healed arthritis so this is one that's been on steroids for a while and you do it but we don't want to make the diagnosis because you need to know what you're treating if you're going to put somebody on steroids alright so we're looking here Chris what do we see in here so it's a fairly so there's a little bit of edema there super old nasally and then it's fairly kind of white disc yeah so this is what could this be giant cell arthritis yeah it could be or it could even be AION could be and maybe this is not quite acute because you see a little bit of power in the air and a little bit of swelling and this is what happens when you get an AION be it arthritic or not this is the optic nerve and if you look right here it's just wiped out I mean you look at that here's some normal nerve down here but you look in this area and it's just wiped out and so what happens is it's those little posterior ciliary arteries which feed much of the optic nerve head that block off with either AION or arthritic AION and then you can get the optic nerve pretty much wiped out alright boy again I keep showing you guys these swollen discs you know here's another one Tara anything different about this one I mean it kinda looks like more like you know 360 diffusely elevated so again if it's unilateral instead of binaural so it's not you know increased intracranial pressure so what's your differential if it's unilateral like AION exactly so it could be ischemic AION could be optic nerve it could be inflammatory again so it could be an optic neuritis could be increased pressure from a tumor blocking it off or something so you always want to keep that in the back of your mind when you're looking at things and we look at this one and let's say that person was 20 and they have this piece of the nerve right here exactly segmental demyelination so here's that normal nerve myelinated here's some segmental demyelination so what would cause that? multiple sclerosis exactly optic neuritis and the most common thing of course is multiple sclerosis so you guys gotta be aware I'm sure that the neurologist really pounded in your head about the trials that were done and how you use your steroids and how you do IV and then go to oral and it's very interesting that study because people used to give patients kind of a moderate dose of oral steroids and it turned out that actually makes things worse and so when you see people coming in with this acute neuritis you gotta blast them with the high dose of IV steroids and then taper the oral steroids and not only does it make the neuritis heal quicker but it actually it may not prevent MS but it certainly will delay MS for up to a couple of years afterwards so kind of important that you treat them right away with the high dose steroids but if you don't you could get this segmental demyelination so this is optic neuritis and this patient did have MS and here you can see kind of a longitudinal view again this area right over here a segmental area of demyelination of the optic nerve seen sagittal now what happens in the long run on any of these lesions Eileen yeah if you look right here there's the optic nerve sheath there's the PM look how big that optic nerve space is and it's not that there's fluid in there pushing it out it's that the optic nerve is shrunk and so anything that can damage it ischemic, inflammatory, compressive, whatever eventually those axons can start dying off and then you get shrinkage this isn't a trophic optic nerve this is an end stage how long does it take when you've had say an acute ischemic episode of the nerve for that nerve to turn pale yeah weeks at least maybe even months and so when you guys are looking in there saying well that nerve looks pretty good that can't be ischemic now because it takes a while for those axons to really die off and for that nerve to turn white and pale so it could be weeks maybe even a couple of months after an event for the nerve to turn pale and eventually it gets a trophic alright Lee what are we seeing here what else are you seeing when you look here again because I know you don't have depth perception in a flat picture we're here look how full that superior sulcus is and you know that's the normal side so when you see it by that our picture the first thing you gotta do is say jeez which eye is abnormal so you're looking here saying which of those two is abnormal but if you look right here look at that sulcus how it's full up there and you almost get the idea that that eye is pushing out something's behind it pushing it out how old is this patient I would guess yeah so they're an adolescent they probably think she was like 10 and so you've got this unilateral kind of proctotic eye there's a fullness somewhere behind it it looks like it's sticking out and then you look in and you see this what are you seeing here exactly are they people call these coradal folds so what are the causes of coradal folds okay and where would the mass be located usually anywhere in the orbit or a particular place in the orbit okay which place you did answer the question you credit for that yeah which particular place so what I'm getting at you have to sometimes play guess what the the person thinking but a mass within the muscle cone behind the eye pushing forward can give you these coradal folds yeah I was taught that you know coradal folds that means there's like a tumor in them so you should be really worried it turns out that's really not true when people look at a bunch of patients with coradal folds it turns out the most common cause is actually just a hyper-opic eye that's kind of flat on the posterior surface you know we used to get excited about these we said oh my god we have border CT scan right away and it turns out you know a hyper-opic eye that's kind of flat can give you coradal folds too so it doesn't necessarily mean a tumor but if you do have a mass it means a mass in the muscle cone all right so this is what happens if you and this is a little over exposed but this is what happens if a mass that's in that muscle cone long enough and causes problems this is a totally atrophic optic nerves you get total atrophic nerve all right so we're looking at the scan here and what are we seeing in the scan so there's a mass right behind the globe exactly so what do you worry about if that was indeed a 10 year old and that was this girl scan okay exactly so you worry about an optic nerve glioma and so what cells do the gliomas arise from astrocytes and so when you look at astrocytomas anywhere in the central nervous system they're graded from grade one the most benign to grade four the most malignant what are the optic nerve gliomas usually uh-huh what astrocytoma grade grade one exactly and so people used to call these juvenile pylocytic gliomas that means hairlike and I'll show you the path why they came up with that but the key thing is these are the benign now Brandon they're growing in the optic nerve they can cause a lot of damage to the nerve and if they go back into the chiasm they can cause damage to the other eye but these don't metastasize they don't spread they're a low grade a grade one astrocytoma and here we can see one that's been removed here's the nerve here's the sheath above it and then you can see this big fusiform enlargement within the nerve itself so these astrocytes are inside the nerve and they're growing into the nerve and here you can see an eye that's been removed and you see this glioma behind it alright so an eco you can see this is why we call this pylocytic or hairlike you know pathologists spend a lot of time in a poorly ventilated basement room sleeping formula and so sometimes see things that maybe other people don't quite say really but in any event you look at this you can see where you've got these spindly cells on here and what people would call a hairlike now there is a feature on here that's real commonly seen in these optic nerve baleons what am I talking about here right there so there's these like isonophilic material the big ones the patient products are these rosenthal exactly these are called rosenthal fibers and so these are characteristically seen in these low grade astrocytomas you get these little pink isonophilic cytoplasmic conclusions and there's a close up of one and they call these rosenthal fibers so you've got this low grade astrocytoma rosenthal fibers now the one thing I want you to remember is if you have a particular tumor that's out of the normal age group in the optic nerve those could be more aggressive so you have a glioma in a kid that's usually a grade one an older adult which is really uncommon those can be aggressive and so you've got to remember if you're outside that normal age range then they behave differently but in a kid with an optic nerve astrocytoma glioma like this these are usually low grade now promise what do you do you cut the nerve out again you kill the vision you let it grow what does it do it kills the vision you radiate these well some people say yeah radiation really helps others say that kills the nerve anyway so you're pretty much stuck can I ask how often do you see optic nerve biopsies specimens very rare very rare because often we go by the scans and you'll see when we talk about these in orbit conference Chris Davidson has really nice scans that can allow us to differentiate these but we do I've seen biopsies on occasion they're very rare that you see them the one problem is if you have what you think is a astrocytoma and you do superficial and you just get the sheath itself you can often get a little reaction to the meninges overlying it but almost looks like a meningioma so you gotta be really careful when you read those superficial optic nerve biopsies you don't over call it this is what I mean by that this is an optic nerve glioma here and you see it's growing inside the nerve squeezing that nerve down but overlying it you get this reactive meningioma proliferation that wasn't a planted question and so you can get this reactive meningio change overlying it so someone does just a biopsy of that and say oh my god it's a meningioma that shouldn't happen in a 10 year old and so you can get this reactive meningioma proliferation but underlying it here's that tidalcytic astrocytoma under here with this reactive proliferation of meningioma overlying it so you gotta be really careful when you do a biopsy that you get this is a glioma with astrocytoma proliferation of the meningophenyl cells Chris what are we seeing here so it's like a propotic right eye with subcutaneous hemorrhage probably you hear that alright so you worry about again something behind that eye pushing it back now the other thing you can say is you can say that this is probably a little Greek or Italian lady because they've got the mustache you are allowed to make fun of your own kind so I'm pretty comfortable with that so I thought it was normal when your grandma would kiss you when you were kid you'd get that little pickle from the mustache so she could also be Greek alright so what are we seeing here Chris what more specifically I'm showing one feature here that's a little funny from an early call that it's a shut it's a shut I mean so if you think about it if something squeezes the optic nerve slowly slowly go and lesion squeezes it it starts getting you can get these shut vessels almost like you get in a central retinal vein occlusion where you can get some shut vessels at the optic nerve and so this is a some more ice cream what is this showing it's like a fusiform lesion on the right talking nerve running parallel with the nerve yeah so what we call this fusiform because it's not in the nerve you know tapering and then growing and tapering it looks like there's something around the nerve and so radiologists they don't sniff form on but they sit in the dark too and so they're pretty better hallucinating and so what it means is there's a nerve in the center and then there's like some thickened tissue around it and so they call this the tram track sign and this is of course the ultimate example of that huge tumor that is pinching on the optic nerve in the center and so what kind of tumor is this meningiomy exactly so I showed you those pictures of those reactive meninges but this is truly like squamous cells they have this pink cytoplasm you see the nucleus with conchromatone and nucleolide there and this is what they look like so if you look at that they almost look like squamous cells and again like squamous cells they often form worlds but in these menygothelial cells when they start to grow you will get these concentric concretions of calcium and hyaline what do we call those somomobodies and how does that spell yeah so there's a double M in there but it's a PS somoma and so somomobodies and these are these concentric calcified concretions that are in there and they almost look like the little squamous worlds that you get in a squamous cell so they look kind of similar when you look at they originate from the arachnoid subarachnoid space now sometimes they can come from meninges senoid wing and come out they can come from the menygothelial cells there and go back and so they can start from any one of those different areas kind of like a astrocytoma these aren't really malignant cells that metastasize but again if you're squeezing the optic nerve you can cause a lot of damage students it's tough to go in there and try to peel these guys off because once you do you kill the blood supply to the other side and you can have a re-put-together sagittal scan here Rhys they pull this mass behind the eye alright so another intraconal mass so we've talked about stuff that can come from that intraconal area around the optic nerve we have gliomas we have meningiomas what else can grow there that's but what else so what other actually there's one other one that may not be coming from the nerve itself or from the little nerves kind of adjacent to it schwannomas so you can even get schwannomas in the intraconal space not common but you can get them in there and now what is the classification that we do for schwannomas a pathological classification exactly so for once there's a pathologist who like wasn't an Austrian or something so an antony named the cell top and there's antony A and antony B characteristic proliferation for the schwannomas so which one is this one this is antony A so it looks vesicular so it kind of looks like you ever see flocks of birds how they kind of sweep together and so that's what this looks like it looks like a big flock of birds sweeping together so this is the antony A running acid and all that around them so I don't think there's a difference prognostically these are very rare but you can get schwannomas within the cone that can't affect the optic nerves okay so say goodbye to the grand ketones and sir so that's coming from the adjacent nerve not the actual optic nerve exactly usually it doesn't come from the optic nerve itself there's little nerves that kind of run around it too but it can't come the grand ketone the middle one has had glaciers on here for you know since the last ice age receded and over the last 20 years those glaciers have receded so much because of you know global warming which is a plot from the Chinese to you know hobble our industries but for some reason that plot that false thing has caused all sadly just in the years since I used to go up there on high call all the time the glaciers are just melting away in another couple decades of record heat you're not going to have any glaciers up on the grand anymore just be bare rock in August alright so with that political aside that I had to speak in there next week we'll be in orbit so know your orbit because there's lots of stuff in the orbit