 Good, now let's see if this works. Is this forward? Oh good There's some things that show up on OCAPs just about every year That we're gonna kind of breeze through then we're gonna have a little show-and-tell session at the end But you need to know how many blood vessels each of the rectus muscles have basically everything But the lateral rectus should theoretically have two anterior ciliary vessel packages Lateral rectus typically has one. Why is that important? Well when we disinsert all of the muscles What happens to the front of the eye? Becomes very unhappy you have anterior segment ischemia So the blood supplied in the anterior segment comes through those eye muscles so we have to use that in planning eye muscle surgery and There are vessel sparing procedures where we dissect the anterior ciliary vessels out of the muscle Detach the muscle beneath it move it back the problem with those procedures is just when you need it the most Usually hit one little thing that bleeds like a son of a gun and you have to cauterize it anyway You need to know about the nerve supply where the nerve supply does it come in on the outside the inside? You know the one that the question that comes up is where is the the superior bleak's nerve supply come from It is on the outside the extra conal side of the muscle tendon Versus muscle and insertion The only muscle it's really You know just muscle right after the insertion is typically the inferior bleak. Whereas the longest tendon is Superior bleak. I mean everything that we were you know, they were talking about Doing things with superior bleak tendon the other day and tucking it Everything that we work on when we operate in the superior bleak involves tendon Because well posterior to the trochlea. It's still tendon The distance that the muscle insertions are from the limbis does show up occasionally And and so these are not numbers to take to the bank that you're going to find Patients are going to obey all of the time But it is typically the case that we have this spiraling You know kind of thing where we go from medial rectus inferior rectus lateral rectus the superior rectus Where we're farther from the limbis spiral of tallow French dude who put his name on there And that is it's worth remembering these I I don't you know I do find it useful at times and just thinking about where the muscle might have been when it's not where it's supposed to be When we're doing reops and orbital anatomy and the relationships of things thinking about the Direction of action of the superior and inferior bleak Versus the superior and inferior rectus muscles the horizontal rectus muscles are pretty nice straightforward But it is the case that the vertical rectus muscles come in at an angle That causes that's why they have some horizontal function. That's why they have torsional function The superior bleak superior rectus is an encyclotorter because it doesn't line up with the visual axis It comes in from nasal to temporal and it rotates the eye and that's why it's an encyclotorter I think that you know those relationships are important to remember And these tables are in the home study course when you look at the angle this 51 degree and and and and 23 degree This is the angle of the visual axis so that there's a much more acute angle with the oblique muscles This difference is what accounts for our ability to separate the vertical function of the muscles when you line the globe up More with the direction of action of the oblique muscles by adducting it You separate out the elevating function of inferior bleak Depressing function of superior bleak and the same when you abduct the eye You're going to line it up more with the vertical rectus muscles And for those of you again who've spent time in the or you know with me You know this we've talked about it for those of you that haven't yet This is something that will become kind of second nature to you But it is part of your what you should be thinking about when you're looking at a patient with verticals to business So you're trying to sort out what's going on And the other you know question that sometimes shows up Although it really isn't of practical significance because we never go back there to look for it is where the muscles originate And superior bleak again is the outlier like its nerve supply coming in the outside It does not originate at the annulus as in same with the inferior bleak The inferior bleak just comes from the floor of the orbit near the lacrimal fossa wraps under the And remember that relationship under the inferior rectus where the superior oblique is between the superior rectus and the globe And those relationships again It'd be fair game to ask a question about that these axes of thick This is like pitch rolling yaw in an airplane or a ship and you can use these axes to describe any movement of the globe Question might be the horizontal rectus muscles rotate the eye around which axis of thick I think that's a pretty bad question to ask because I don't expect you to remember these things Just conceptually that those axes exist. I don't care what the names are but somebody might and so X is across You know y comes out at you And z is the other one And that may be a way to remember it, but that's how I remembered it when I was a resident Movements of the eye and we talk about monocular movements, which are adduction abduction Superduction infraduction We also have in cyclo rotation x cyclo rotation In cyclo for each eye you put a mark at 12 o'clock rotates in towards the nose So those movements are in opposite directions depending on the eye that you're talking about And then there are the Binocular movements those that go in the same direction and that would be dextroversion Levo version superversion infraversion for right left up down gaze and then convergence And divergence and actually our virgins movements We you know, we have the ability to pull things together not just horizontally, but also vertically and Torsionally and it's useful sometimes to think about those things As virgins tight movements as well On the other hand being that nobody's identified a specific center for those things kind of hard to make an argument for that on a You know, neuro ophthalmologic standpoint herrings law herrings law is important We use that regularly Gives us a chance to mention yoke muscles yoke muscles My right medial rectus my left lateral rectus are yoke muscles They both move my eyes to the left and the brain should send equal Intervation to each of them. Why do we care about that? Well, let's say I have Dwayne's type 2 in my right eye My right eye tries really hard to adduct can't do it and The same amount of neural input goes to the left eye. So I want to put this large angle Exotropia because of herrings law Equal innovation and typically whichever eye you're fixing with that's going to be the driver as far as how much neural input there is Contrast that with sharington's law, which basically says that antagonist muscles My right medial rectus my right lateral rectus are antagonists When we activate the right medial rectus, you see a lot of firing You should see a decrease in firing relaxation of the lateral rectus The you know, the other example of that would be the dwayne's patient That you know, the co-contraction issue the reason the co-contraction occurs What happens when you have that aberrant fire firing from the third nerve Intervating the lateral rectus in a patient who's got dwayne's type 1 You wind up with Simultaneous firing of both muscles that pulls the eye posteriorly Passively closes the lids. Why does the eye adduct? You know in type 1 dwayne's well the reason it adducts is simply that the medial rectus is stronger than the lateral rectus And that's why you never Resect the lateral rectus in a type 1 dwayne's why if you suddenly given an advantage And let's say I've got dwayne's type 1 in my right eye. I try to look to the left I've recessed the medial resected the lateral my eyes are going to do this You wind up with about 200 diapters of exotropia and very upset parents I have seen that happen. I think once in my career where somebody did that And then I got to see the patient and this was like the day after surgery When somebody did that fortunately I took the kid back to the or a couple of days later and Took care of what they had accomplished with the lateral rectus by moving it back a whole bunch and Everybody was happy and nobody got sued now Diagnostic positions of gaze keep in mind that primary position Up and down there's a combination of things going on in primary position You got all kinds of firing going on to maintain that right? But if we look at these positions here There is one muscle that is primarily moving the eye Those are questions someone might ask you saying in gaze up and right the major Elevator of the right eye is and the answer is going to be or up and left rather the inferior bleak You know the major elevator of the left eye is the superior rectus those questions You know are something that you might they see a question on and and so those are the what are called cardinal positions And these are on the other hand the nine kind of diagnostic positions of gaze And some people add to that the issues of head tilt right and left. That's another two primary position And down gaze at near another two for 13 positions if you really want to be picky um And that originated with burt kushner the guy that was that eileen I had that nice article about the other than as his kind of way of looking at that And I think it is actually a good way of thinking about laying out Where things are misaligned Now we're going to talk about sensory physiology because this stuff does show up some of it is actually useful Much of it is not This is kind of interesting and you can play with this at home And it's kind of cool how it works You know the idea is although there are lots of circles and lines here What's going on is that both of these eyes are looking at this point f while they are looking at this point f there is a theoretical construct here, which is called the empirical Horopter and that structure that plane, which is it's actually a curved surface That looks like a torus Anything on that plane is going to be projected on exactly corresponding areas on the retina in each eye Does that help us a lot? Not really But what is cool is this area here and and this this idea here of panum space And what happens you notice that this between these two kind of You know broad curves here the space near the point of fixation is narrow and the farther you go away from it Where things are going to project onto peripheral retina farther out in the periphery the farther you go the larger the spaces If you want to experience this at home take a piece of wire coat hanger and hold it out and basically look at something And and move it back and forth and notice because and we look at the coat hanger Where it's single and where it's double and very close to what you're looking at You don't move it very far and it's double But if you hold it out here and you go back and forth You have to move it quite a ways to appreciate the plopias So the question that would come from this is When the patient is looking at point f an object seen inside Panum space would have and the answer is stereopsis meaning that you would see that object as either closer Or farther away than point f whereas if the object is outside panum space You appreciate it as being double because you the brain cannot put those two images together That's the significance of that and and although they may try to make it More difficult now this issue of retinal correspondence When the eyes line up normally there are corresponding points in the retina that relate to each other And when the eyes are straight we call that and everything lines up as it should normal retinal correspondence Anomalous retinal correspondence is something that only happens with childhood Strabismus period end of story If you see an adult who has anomalous retinal correspondence The only way it ever got there is that the eyes were misaligned at some point in childhood And things developed abnormally because it requires a developing visual system to develop anomalous retinal correspondence And we divide this into two groups harmonious Meaning that from a sensory standpoint I think things line up the same way that they're misaligned Or what is called non harmonious where let's say I measure things and I'm measuring 50 diapters of esotropia I put the patient in the amblyoscope where you can line things up with targets and tell from a sensory standpoint How misaligned they are and they say they're only 20 et How did that come to be usually because there were different Amounts of misalignment at some point in early childhood And so things developed, you know, the visual system isn't perfect. The whole reason this happens is to avoid diplopia Now suppression suppression is a binocular phenomenon where if my eyes are misaligned I see things with one eye and I ignore enough from the other eye Defined by a scatoma that's only there under binocular viewing to ignore diplopia Monofixation is a special circumstance where you have an abnormality In binocularity associated with very very small angles to business That is a stable arrangement for infantile esotropia That is for most patients the most desirable outcome Why because it causes them to be stable from a motor alignment standpoint They don't see double They may have a little bit of amblyopia and that's where a lot of the amblyopia even with successful outcome for surgery for Infantile ET comes from Monofixation digress for a second four die after base out test Great test elegant test for monofixation questions show up about that The normal circumstance when I'm looking at a small target with both eyes if I have normal binocularity Is that you will see when you put a four die after base out prism in front of my right eye and you're looking at my left eye You will see a version movement to the left side because you've displaced the object on the fovea in this eye And then because it's no longer on the fovea in this eye because of the version you get a vergence movement So you should see two movements when you introduce that prism now monofixation syndrome If the problem in the scatoma is in this eye when I put the four die after base out prism here Assuming that the scatoma is at least that large You'll see no movement You know you may see no movement at all you put the prism there and this eye sits still Whereas if the scatoma is in this eye What will happen is I put this here this I still knows that the image moved off the fovea So you see the version movement, but no vergence movement. Does that make sense? Something you need to think through and that's the way they may ask a question about that now Yes So Monofixation is a type of suppression then it is it well it involves suppression But it also is usually an abdomen. I think of it as an abnormality and binocularity But with with stable motor alignment very small angle esotropia almost always kind of Well, there has to be a scatoma associated with it to allow the patient not to have the plopia they suppress when they're binocular And and that allows the situation to result Now if you were to measure them you do a visual field test and say there's a scatoma on the patient Their visual field is going to be perfectly normal But these are and where you look for this clinically is in in the patient who shows up in your practice And they've got mild amblyopia They have equal amounts of refractive error You don't see anything on cover testing And you know and and and because you sat through my lectures You're kind of saying I have to have an explanation for the amblyopia and how it got to be there And and you look and they've got some stereo Let's say they get two of the circles on the titmus test So they've got some stereo acuity But not high normal and then you do this four diopter base out test and you say, oh, it's abnormal You know the patient's got mono fixation That's why they have amblyopia in this eye and that is useful because otherwise You got to kind of beat yourself up trying to find an explanation for it. Does that make sense? Now This issue is a key concept Diplopia and when we have an iso deviation we have uncross we have uncross diplopia Cross-diplopia meaning that if I am looking at this this is the image seen from my right eye This is from the left eye if I am esotropic I'm going to see The right eye image on the right side left eye image on the left side. This is assuming normal retinal correspondence And then if it's exo it's on the opposite side. Why is that? Well, if you you know From the phobia thinking of the phobia is a zero point and everything Lateral to the phobia as being temporal retina everything nasal to the phobia for all these discussions of binocularity Everything nasal to the phobia is the nasal retina the temporal retina sees things over here Nasal sees things over here sees temporal space nasal space for the temporal retina And you have to think about it that way so that if we change our alignment So I have esotropia the object of regard is going to fall on nasal retina Nasal retina tells us that something is often temporal space. You just said that right? Which is why you have uncross diplopia Whereas if you have temporal retina looking at the object of regard Normally temporal retina tells us that something is in nasal space So it takes the object to regard and moves it across And that is the key to figuring out all of these things with the bageline lenses and the after-image testing You have to understand what the test means But if you understand those two concepts you can figure out the rest of it now Levels of binocularity to digress for a second. It kind of you know, we have different levels and degrees of binocularity simultaneous perception I see something with each eye at the same time Sensory fusion I can put the two images together and then stereopsis I can use the idea that my eyes are separate in space To discern an element of depth and stereo acuity And those are, you know, each one is a little bit better binocularity An example of simultaneous perception when I take these two dissimilar images and the patient tells you they see the chickens inside the cage You know that they're seeing both of those, but there isn't anything in either image that they actually had to line up with the other So it it could be that the chickens are a little bit off-center one way or the other and it still counts On the other hand to see this image They've got to be able to superimpose the two boats The other figures and if they tell you this is what they see both guys And the element, you know the elephant in the giraffe and the camel out there You know that they are actually putting that together fusing the two images And so that is another you know a little higher level And then when you present stereo targets and they tell you that one is out in front of the other They see the wings and the tip of stereo test or the circles or the the little Dots sticking up and they can identify those correctly and you're sure they're not using monocular clues Then you know that they've got stereo acuity, which is the highest degree of binocularity And I'm not going to dwell on this you can read about this, but there are different cells groups that have to do with Form and motion perception color perception In the organization of the visual system And I think that's something important to read about and understand at some point Now we're going to talk a bit about tests of binocularity the worthless four dot Bagolini lens, which isn't used for binocularity I use the bagolini lenses when you see them in my clinic I'm using them to measure torsion because I think it gives a better real word Measure when you're talking about torsion on ocaps You'll almost always get information related double mattox rods because that is what most people do and I just I don't agree with doing it that way because It's dissociative when you have those mattox mattox rods there Patient can't see anything through them to orient themselves in the surround And so I think it gives a less real world measure of torsion But I'm a minority opinion in that after image testing these things This these make really good boat anchors at lake powell But are rarely used in practical situations some orthoptists use them It is actually a very nice, you know instrument where you can measure both motor and sensory alignment With the patient it's a very cumbersome difficult to use piece of equipment very time consuming And I don't think it really gives us a lot of additional information But again orthoptists like it and there are some of them around we had one in the department for a while And i'm not sure where it disappeared I did give my I have an after image test that I think has been found after a considerable foray in the neuro ophthalmology clinic So the word for dot is used to assess binocularity. It is not a test of stereopsis that could show up as a question and we'll look Pardon me at it'll give you Information about suppression Diplopia And um, this is uh, il de capos. She's a pediatric ophthalmologist down in bascom Palmer And put together this slide set and I thought this was a pretty cool picture of her with these glasses on Red lens goes before the right eye green lens before the left eye And what you'll see if the patient is binocular is some combination that looks like This where this one could be red green pink something, you know in that area. That's the white, you know target and But they take their four targets the patient sees all of them And that is the normal circumstance if they are seeing just with the right eye You see this just with the left eye You see this if they see this they are And if you get any other combination there is usually something else wrong with the patient And their math abilities are good Now the bagelini lenses Bruno bagelini was an italian ophthalmologist And these striated glasses are actually pretty cool. It's just like a maddox rod And With the lenses fixed in position You when you look at a light source like the transluminator with these striated glasses You will see perpendicular to the striations a white line And we use that to try to get an idea just Of where things are you don't really need the line all you need is the image of the light And what they're trying to do is to decide with this Bagelini lens test all you're looking at is whether you have Cross non-crossed apropia basically So let's kind of look at this and this is a situation where if the patient is orthophoric These lines refer to the striated so the the line they see each eye is seeing this dot If they're at apropia the dot will be separate in space horizontally if they've got horizontal Diplopia if they've got a little bit of suppression in one eye mono fixation Uh, you know thing going on you'll see a little gap in there But patient's ability to actually see that and tell you I've tried to use it and patients is almost non-existent I've not been able to get a patient to appreciate that and and so If you have normal retinal correspondence And you've got esotropia You're going to see something like let's come down to this right here Normal retinal correspondence with the plopi and this is the these are the questions they ask you right here In all this refers to again We said with the right eye, you know image off to the right left eye off to the left Is that crossed or uncrossed apropia? Uncrossed the right's off to the right and that's all this means I tried when I was a resident to remember whether the dots were above or below and make sense of this because nobody Really explained this to me till I said played with the darn thing and tried to figure out what was really going on and all this is is Uncrossed and crossed apropia again what we've got this is the right eye image here The right dots off to the left the left one is off to the right It's crossed apropia and this is the patient who's got normal retinal correspondence with the plopia and exotropia Now this is the patient right here is just suppressing one eye entirely dense amblyopia. This is the patient who's got a fairly large Area of suppression And those they typically won't show you on that test the after image tester I don't think you'll ever see anybody use their historical significance Basically what it is is a long light Bulb with some sort of mark around the middle of it to keep you know from having the light shine right there And you show it to the patient both You know vertically in one eye horizontally in the other eye and then you ask them what to see So keep in mind with the bagelini lenses We're having both eyes open and we're looking at a light target looking through the glasses, right In this circumstance, we're labeling the phobia assuming they use the phobia to see with in each eye And then you're asking the patient Where do we think the phobia is? And so with this What happens is this again is uncrossed or crossed apropia, but what it comes down to Is where the phobia thinks it is if you know the question might be You've got a patient who's got normal retinal correspondence They've got 50 diapters of et they've got 10 diapters of hypertropia and 20 degrees of encyclotortion What is their their after image test going to look like it's going to look like this always if you've got normal retinal correspondence If the phobia in one eye Is relating normally the phobia in the other eye the patient's going to be diplopic But this test which asks the question. Where does the phobia think it is? It's always going to line up Now on the other hand and they just do this for iso. They don't throw in the other Test, but the idea is in the circumstance where you've got anomalous retinal Correspondence and i am esotropic and you need to think through this Okay, so something in my nasal retina in a patient with esotropia is lining up with the phobia in the other eye With me so far Okay, so where does the phobia think it is the phobia thinks it's part of temporal retina, right temporal retina Is what we see when we have you know as part of temporal retina Tipple would be an exotrope with cross diplopia and lo and behold what they tell us is that the image Is crossed the right side is over here the left one is here here This is the vertical presentation of the left eye horizontal to the right eye And so that's how that works and this is the way to think through this It's a matter of where the phobia thinks it is So when we look at the patient who is exotropic just to go through that from a different perspective My right eye is exotropic So with anomalous retinal correspondence Some part of my temporal retina has learned to relate to the phobia in the other eye That's and and so the real phobia is part of nasal retina and assuming the patient has good vision That's what we labeled with his after image test. So the question is where did the phobia think it is? It's part of nasal retina nasal retina is what we see when we're et Saying that we're looking at temporal space and we have uncross diplopia and indeed this should be an r It's just cut off. There's not an f Right eye moved off to the right side left eye is here uncross diplopia and that's all these things mean does that make sense? Okay, and those so that I think that just being able to quickly think through that question Probably good. Is it going to help you with patients? Probably not Um, I do have again my my after image test or surfaced. I think it still turns on So if somebody wants to play with it, it is kind of cool. You can probably have fun at parties with it um Now the titmus test monocular clues the idea is if you look at the titmus test without the glasses on Most of you can get at least four and probably five or six of those circles, correct? Just by the blurring the way to separate that is if you take the book and you turn it upside down The circle that's stuck out will now look like it's going away If the patient tells you that you know that they are using stereo acuity Because kids are good at figuring out how to answer tests and getting rewarded for doing a good job And so they see the tech imitating, you know trying to pick up the fly So they hold their hand up here and try to pick up the fly and then they point out all the blurred circles And I have seen that happen again and again and again where you have a patient who's got huge strabismus And someone in our clinic will work the patient up and tell us that they've got five out of nine circles on the titmus test And then we you know, I checked them and they've never had any stereo acuity It's important in terms of giving parents useful information and not misinformation The randot test is another stereo acuity test that doesn't have The monocular clues, but it is difficult at times for kids to catch on to what the image is And so they have to be older to get it, which is why we don't use it in young children This is showing the the titmus stereo test in case you're not familiar with it And the amblyoscope and again, just imagine that stuck in the rocks at the bottom of Lake Powell It would really grab on and keep the boat from moving Moving on to amblyopia amblyopia occurs in about two to four percent of the population These are the kind of, you know common causes strabismic Anisomatropic difference in refractive air in the two eyes amatropic both eyes out of focus Deprivation crowding phenomenon refers to a phenomenon where if you take an amblyopic eye You present single optotypes. They will do better on the acuity test than linear optotypes You can simulate it with the surround bars that are now present on a lot of the automated projectors that we use But and that's what has been used in a lot of the studies organized, you know group multicenter trials of amblyopia But you don't want to have somebody just presenting isolated figures. You will miss amblyopia in small kids Treatment basically involves eliminating the cause whether it's strabismus deprivation if they've got severe ptosis You fix the ptosis Equal clear images and this is where doing a good refraction getting them in the appropriate correction So things are clearly in focus in each eye as key occlusion Of the preferred eye and the mantra if you're going to do full-time occlusion that sometimes show up is you don't want to do More than one week of full-time occlusion meaning all waking hours In a child one week per year of age Do we typically occlude them all waking hours when I was a resident that was commonly done Since that information has presented Been, you know, kind of in generally accepted that doing more than about four hours a day rarely gives any additional benefit And so That makes it so much easier for parents to do it penalization refers to using Atropine drops to blur the preferred eye So that the child will use the other eye that's been shown to be effective in kids between three and seven With visual acuity between 2030 and 2100 in the amblyopic eye So if the vision is worse in 2100 you probably cannot blur vision in the preferred eye To get them to use it so you don't want to use it in that circumstance And if they're not old enough to measure acuity you probably do not want to use it that you know The studies basically were done in kids three and older We were one of the study setters for the early studies the amblyopia treatment study with that And now as far as strabismus in general terminology, we're going to go through but You know et x t with a parenthesis around the t that refers to an intermittent deviation With a little accent over the deviation refers to a deviation at near Types of deviations we can talk about deviations either horizontally vertically torsionally or a combination of them And we're going to talk a little bit about tests about angle kappa and the three-step test so now Specific strabismic problems we're going to look at just a little bit here infantile accommodative Peretic and other forms of esotropia This button is very sensitive and then exotropes intermittent infantile infantile et is Or x t rather is something that is very similar to infantile esotropia Meaning that they've got large angle misalignment in the first six months of life they don't Ever usually get normal binocularity And and they need to be operated early Sensory exotropia refers to the circumstance where you've lost vision in an eye and the eye turns out interesting And may not occur to some of you yet that if you lose vision very early in life You typically have an eso deviation as a sensory deviation due to convergent tone Whereas if I suddenly had a central retinal artery occlusion in my right eye It would almost certainly drift out over time not drift in it's age dependent vertical deviations think about DVD thyroid ophthalmopathy oblique dysfunction. We're going to talk a little bit about a and v patterns Now we're going to do that while we go through show and tell so what's going on with this patient Is esotropia or exotropia Which eye is fixing Left eye very good. And I mean, could this be dwayne syndrome? Yes. Could it be a six nerve palsy? Yes, not likely dwayne's because you don't see any evidence of co-contraction with that eye, you know adducted More likely looking at this child. It's you know, could be infantile et also could be a cognitive et if they suddenly showed up like this This patient on the other hand is exotropic You see the eye notice which way the light Is shifted look carefully at this patient. Tell me what's going on here This is where you need to have a red flag go up and you worry about this kid And you send this kid right to the scanner Because this eye has turned out it's going down And the pupil is a little larger the lid is down a bit Can that be described by anything one of the questions when you see a patient with strabismus You should always want to ask yourself could this be a cranial nerve palsy, which cranial nerves again innervate eye muscles? Three four and six right And so basically this is the left third nerve palsy that showed up suddenly in this kid who did have a brain tumor Causing it. So this is where instead of saying gee we need to get this fixed We need to patch the kid or put him in glasses You need to send him to the scanner and figure out what's going on And this is an intermittent deviation when this cover is removed from the right eye You have this iso deviation that was not here in the top Now as opposed to aphoria where it is only present when you disrupt fusion Important distinction. This is here so you can take a picture of it Whereas you know if it was aphoria you'd have to look under the cut You know you're watching while you're cover testing but as soon as you take the cover away the eyes straighten right out and they stay that way This patient is interesting. We see patients like this a lot in clinic Where parents are absolutely convinced that the eyes are crossed But when you look at this patient with the cornea light reflex when you look at the brookner test You do a complete exam and you think everything's perfectly normal cover testing everything's nice and straight And look down the road how the same child Looks absolutely perfectly straight now and it's due to this gestalt about the amount of white that you see on either side Realizing that that photograph was taken with the patient looking off to his right just a bit Now angle kappa angle kappa Positive angle kappa pseudo exo deviation negative pseudo et What does this have to do with angle kappa just describes the circumstance where the visual axis And the pupillary axis are not lined up And most common the best way to remember that is that in retinopathy prematurity If you have to figure this out where the retina is usually dragged Temporally So the fovea is displaced temporally the eye is going to turn out to line the fovea up with the object to regard And so it looks for all the world like they're exotropic. That is positive angle kappa That's the kind of quintessential example of it And in fact, I have seen over the years many kids Post premies who have had severe rop Who look for all the world when you look at them like they've got 30 plus diopters of exotropia I mean large amounts, but when you do cover testing, they're actually eso So from motor standpoint You know and the parents are concerned because grandma thinks the eyes turn out and you say well They actually turn in and if we want to help your child's eyes look together We're going to make her look really funny And parents don't go for that But I think it's way cool when you see it. I mean, it's just you know, you say I could sit and look at that all day long It's it's just it's it's really exciting. Now. This is done by folks at walmart everywhere The red lens test and on the neuro ophthalmology service, but I I don't do it by and large. I think that I'd rather Measure the deviation and have an idea what's going on not use this to infer that there's a deviation What you do with the red lens test is you look at a light source like this very bright one we have here And you have the red lens in front of one eye They see a white target red target and if they put them together things are fine And if not you could see uncrossed or crossed a plopia if they are iso or exo You can see vertical deviations to get an idea what's going on But it's a quick and dirty way to look to see, you know, whether their eyes are lined up Most of the time you're already going to have a pretty good idea and you can also do it with the um Maddox rod, you know do dad here on the on the other end of the collider That's why it's on the other end of the collider is to do this It isn't just to make noise to get kids attention in clinic But the idea, you know with this is you're going to see something that looks like this That vertical red line caused by the little bars in the Maddox rod And a a white light and if they're superimposed their eyes are generally lined up And and that's actually a pretty good, you know thing that we have school nurses do that to screen for misalignment I think it is a good thing And this is the Lancaster red green test I also have one of these that disappeared into the world of neuro ophthalmology in the old miran eye center And has never resurfaced Um, it's probably in somebody's closet or one of the fellows took it with them It's a way to measure You're presenting one target the patient's presenting the other and it's a way to kind of map out where they're how they're misaligned Now this is and and we're talking here about patient who is Diplopic and if they're diplopic you may see this they may actually see What would otherwise be a normal response that they've got anomalous retinal correspondence um And this is this is a picture of an after image tester This one the the light tube is inside this metal box And so what you do is you have the patient stare at this thing and the light comes out here So you wind up with this after image when they're staring at the spot for 30 seconds And then you do the other eye and you ask them what they see Now this is an example of where you might see and the question might be You know the big concern with this child would be It would be anisomatropic amblyopia Strobismic amblyopia deprivation amblyopia um cosmetic appearance And the answer would be deprivation amblyopia because this is occluding the visual axis and the current Invoke treatment for that if they were to ask about it would be to use which medication Um Pardon Prepranolol, yeah, prepranolol, and you you know people can use it topically Probably not this you know would probably be better to use it systemically And um and and the the one exclusion criteria is if they have facies ph8 ces syndrome You do not use it We have a we admit kids because kids can have bradycardia And uh, you know fairly dramatic hypotension with this And kids have had real serious harm with the spacy syndrome Due to you know cardiac issues associated with it So if there's any question we have the pete's cardiology folks see them But we get them on prepranolol and these things shrink away Now this patient here when you look at this and they are looking through Without glasses and then with glasses and notice that the eyes are nice and straight here This is an example of accommodative esotropia where we relax focusing with the glasses the eyes straighten out In this patient The really cool thing is that it near they're crossed with the glasses and then through the bifocals They are nice and straight And that is an example of a high aca ratio accommodative convergence To accommodation ratio meaning that it's a measure of how much crossing you get per unit of focusing And most folks with the accommodative estropia have equal amounts of crossing a distance and near Those of the high aca ratio have excess crossing at near Even usually when they're wearing single vision glasses to control things at distance We put them in bifocals their eyes are nice and straight at nearer which improves their binocular area Their ability to read function in school And trip over things because the bifocals do get in the way But kids adapt to it much better than adults do This patient alternating fixation fixing here right eye fixing left eye has infantile esotropia Has equal vision and so a question might be your next appropriate action Knowing that they don't have significant refractive error everything's healthy anti-segment fundus And seeing that they will maintain fixation with each eye Is to do what if you're taking oral boards, they might well ask you What your next step would be and the next step probably should be to do some surgery And give me an example of an appropriate surgery please to do for this Right either a probably bi-medial recessions if they've got equal vision Recess both medial rectus muscles would be the most common Thing done an r and r certainly if they'd had ambliopia in one eye Might be the ticket check for obstructions decide between the two And usually when if they give you an example like that they're going to have something that just doesn't make sense Like recess both inferior rectus muscles or recess both lateral rectus muscles You know so that it isn't going to be a close judgment call It's going to be a this makes no sense and this one does make sense Now this is when we talked earlier about sensory deviations This is a morning glory optic nerve optic nerve coloboma this eye has very poor vision And it has turned in so in follow-up to what Julia just said if you're going to operate on this child The appropriate thing would be to On the right eye Because you don't want to operate on the good C&I you don't want to subject it to even the small risk of having something bad happen this patient Pardon me has had cataract surgery in this eye This was the show the asymmetric fundus reflex when you're 20 diopters out of focus with one eye Andrea esotropic. She took her contact lens out for that photo And wait a minute Come on. There we are now this patient. This is actually one of my original Kind of it should be chris kumans counterpart here her daughter Who posed for this picture who had Esotropia had this appearance in her right eye. What's wrong with this? What she got Hypoplastic optic nerve and they'll show you something like this and ask you, you know, what's going on They might ask you what else you would worry about and that would be growth You know development a pituitary hypo phlegmic function Um optic nerve hypoplasia when you first glance at this this is the scleral opening This is the nerve These folks will typically have abnormal branching at times tortuosity of vessels the vessels don't look quite normal as well But this is one of the two most common things when I see kids with decreased vision and nystagmus where some Very capable ophthalmologist has looked at the patient and has missed the diagnosis They have either optic nerve hypoplasia or albinism This is a pretty counteract this on the other hand notice the blood vessels here This is just prior to a nucleation for this retinoblastoma That was picked up when somebody a pediatrician looked at the fundus reflex Why you know, they hadn't come in before with the eye turning out. I'm not sure Um child actually did well and this patient's got a third nerve palsy And she's trying to fix with that Um Left eye and you'll see that she's when she fixes there. She's got this very I'm sorry left eye is the third nerve palsy. She um, you know, it has this big big secondary deviations She's fixing with the peretic eye This guy likely has infantile esotropia and you look at that We've got you know, large angle esotropia You'd want to see make sure visions equal do a complete exam, but likely need to do surgery Um, this is my daughter when she was very young and notice that if you look at her brookner test Look at the the light reflex. It's asymmetric. You can also tell she's about 30 et She took her glasses off for that picture. She has a combative estropia She now wears contact lenses. She still needs those to keep her eyes straight. So not everybody outgrows it Um, this is andry interglasses just to know so you know that I didn't take terrible care of my daughter um, another patient, you know, we I see kids all the time Particularly, you know, asian kids With a wide flat nasal bridge and the assumption is that it's always pseudo esotropia And this just goes to show you can have a flat wide nasal bridge and still have very large angle et Looking at that kid that kid's got infantile et um, and now looking at this what we're seeing here is Um, basically some dvd. You see that right eye going up and we take that away. This is manifest right dvd And this is a patient who under the cover just has latent You know dvd when he's dissociated you see the left eye drift up here. You see the right eye drift up here This patient we would just watch the other one if it was noticeable we might operate on Now when you see a child with a head tilt on ocaps Almost always the answer is going to be a fourth nerve palsy They're going to ask you about something to make you figure out which one it is And we've got a child here who's got a left head tilt Okay, so which fourth nerve is in question? The right And when we look here look what happens when the child tips his head to the right that right eye is way up there When we tip the head to the left, they're absolutely perfectly straight. So this is an adaptive mechanism This is a guy who also shows us fundus x-cyclo torsion the phobia that should be here is rotated x-cyclo And he has a right head tilt Right face turn and a little bit of a chin down head position, but not much those three things head tilt Face turn chin up chin down You can use like pitch roll in the odd to describe any abnormal head position So which fourth nerve? That's correct Well, you know, it's the left eye But on the other hand, don't be misled that you could see the right eye looking x-cyclo rotated And they could show you because I have seen many many patients where the thing driving it is one eye And when you measure the torsion it's measurable in the other eye You know if they prefer to fix with the peretic eye So that is I wouldn't but but yeah, there is a likely clue here But in any event he's got a right head tilt. So it would be a left fourth and This is a close-up showing that rotation and now This patient what's going on here? We have this dramatic limitation of elevation and I want you to give me two possible answers Two possibilities that that could cause that that you'd need some additional information to sort out We've got limited elevation of the right eye and adduction Browns and what else? Inferno oblique paracels And you separate the two by checking for instructions and taking hold of that eye with an instrument if it's tight It's browns if it's not it's an inferior bleak paracels. Do inferior bleak paracels happen? Yes, they do and If you're trying to fix that the thing to do usually is to recess the contralateral superectus to match things It works And now what's going on this patient is trying really hard to look up being really cooperative And when the eye is adducted it doesn't go up in primary It doesn't go up in abduction. It really doesn't go up. So what would this be in set of browns? Or the new trendy term is monocular elevation deficiency I do still call it double elevator palsy But that's I'm allowed because that's what it was when I learned what it was Um, and and so this you know is an entity where you may well have ptosis You'll have limited elevation across the board. It can be due to paracels of superectus Those kids more commonly have ptosis. It also can be due to a tight inferior rectus. So as a descriptive term covers the waterfront in terms of a number of different entities actually and what you do to fix it depends on How tight things are below if it's tight you need to recess the inferior rectus If it's not you do a transposition of the medial and lateral to the superectus to get the eye up What's going on now this patient? Here is try is is trying to maintain fixation He's got a little bit of leftisotropia Notice when he tries to look to this left side this eye doesn't go out But the fissure widens you notice that it's a little narrower here. He's got what? He's got left wings type one And when you look at this patient again, notice that he doesn't abduct here But there you know, there isn't as much fissure change with this this patient's got a left six nerve pulse This is dwayne's type three and type three again. The eye doesn't move a lot and I part of these from the home study course I didn't have a good photograph of a dwayne's type three But the idea here is the eye she's trying to look to the right. It doesn't abduct She's looking straight ahead. It looks pretty straight And then when she looks to the left it doesn't adduct and those patients yet You can do things surgically to get them lined up straight ahead But you're never going to make the eye move normally So I would resist doing huge surgical interventions It won't be a happy outcome And this patient with this wide-eyed stare came over from the va has He's got thyroid eye disease and that right eye is looking down at the floor It's turned out a little bit and we're going to watch him till he's stable We're going to ask him to stop smoking and then we're going to straighten his eyes out This is another patient from the va with thyroid eye disease Um Very dramatic limitation of elevation of that eye General principle in in in thyroid eye disease is to recess muscles not resect them to improve range of motion First thing we do is deal with the orbital issues if they need to have a decompression you do that Second we get the eyes lined up third. We reposition the lids Lids often need to be repositioned just to protect the front of the eye And I need to let you guys go But this kid there's a family picture that he also had of everybody in the family All with their heads tipped back like this kind of looking down their nose on the porch for the family picture What is this? His congenital fibrosis the extra ocular muscles. He's got ptosis He can't when he tries to look up his right eye goes wing and way out to the side, but he can't get his eyes up We can do surgery to try to get those eyes into some semblance of normality in contrast to this patient Who has myasthenia gravis who shows up with variable diplopia ptosis? This fellow has the same And so does this child and this is after tensilon and look what happened between this picture and this picture When you see patients with strabismus that doesn't make sense think about myasthenia You know, I remember a patient I saw one as a fellow I saw and the kid had ptosis on one side in large angloxatropia My fellow fellow called me a couple weeks later and she said boy, you really had a bad day She said this kid you wrote the ptosis on the wrong side in the kid's esotropic not exotropic And I said well, how about if we kind of give that kid a little tensilon and see what happens and the kid's eyes went boom and the eyelids went up and and you know, it was it was very Surprising but Got to the bottom of it. This child has Never smiled in his life. He's got a funny looking tongue His eyes stay right here. And when he tries to look from side to side, they don't move at all What do we have? Maybe a sequence. Yes And then what are we seeing? We look pretty good when we're going to the right here Straight ahead things look pretty good And we look to the left and the question here might be where would you see an abnormality on this patient's MRI scan Well, or how about if you saw a plaque in the mlf? This patient's got the myelinating disease. This is internuclear aftalumplegia And lastly just a and v patterns to look at this quickly. We've got here we talk about an a pattern. We either have more Exo or less eso and down gaze Than up gaze and for a v pattern more exo or less eso and up gaze and You divide your thinking about this and that's how you want to think about describing those that if you Think about what the patient looks like with a pattern esotropia They're very crossed in up gaze their eyes are in here and as they go down their eyes straighten out That's why it's called an a pattern with the pattern exotropia as they go up their eyes go out Looks like a letter v And so picture what the patient looks like you'll be able to figure out whether it's a or v And then the questions they will ask about fixing them by and large have to do with what would be a regional you know procedure to do If there is oblique dysfunction you deal with the obliques if there isn't you shift the horizontal muscles and in general With medial rectus muscles you always Go towards the pointy end of the v or the a if it's an a And you shift the laterals towards the open end If you remember that you'll be able to figure out the answers and this shows a child who's got an a pattern Esotropia et in up gaze almost turned out in down gaze This patient has a v pattern where he's almost ortho in down gaze turned out dramatically in up gaze And this child talking about oblique dysfunction notice this right eye looking left gaze looking up at the ceiling Left eye looking up at the ceiling. This is inferior oblique overaction In this child who has a v pattern turned out here Turned in down here So then the question is what to do because we're pretty ortho a little et You know in primary and what we would likely do here is a little bit of surgery for the primary position Esotropia whatever would be appropriate and weaken both inferior obliques That'll get rid of the x t and up gaze And it will collapse the pattern So primary, you know thing again Do surgery for the primary position deviation and then take care of the oblique dysfunction. I think we're going to stop there I didn't get through retinopathy prematurity Read through that if you want to look at this. I think the talk is recorded Somewhere it should be in your collection of things that I've sent to Elaine And if you have questions about any of that that we didn't get through just because it is a lot of information Call me and I'm happy to go over it with you. Okay any questions Get out here and have a good day