 Good morning everyone. Good morning everyone. Welcome to Grand Rounds. I'm Chris Connerty, one of the new interns. And our first talk this morning will be back to the basics elimination techniques by visiting student Joshua Atkinson. He's an MS4 at UT Medical School, Houston. So give him your undivided attention. Thanks, bye. Good morning. I'm Josh Atkinson. Today we're going to be talking about something that everyone here is pretty familiar with, but we're going to have a little bit of fun at the same time. So I actually went to school in Austin, UT Texas, where we take our football very, very seriously. And if you follow football at all, this is two weeks ago, UT versus BYU, didn't go so well. So then I went to med school in Houston, where we have a plethora of new sports teams to follow. The Houston Astros, this is 2013 51 wins to 111 losses. If you are unfamiliar with baseball, that makes them the worst team in the league. Houston Texans, two wins, 14 losses. If you're unfamiliar with football, that makes them the worst team in the league. And the Rockets, they did pretty good. But the one thing that we're really proud of in Houston is the Texas Medical Center. It's the largest medical center in the world. It's over 1,300 acres. It has over 7,000 beds and has over 100,000 employees. If you've never been there, it's a great place to go visit. It's a lot of fun. But anyway, let's get back to the matter at hand. Today we're going to talk about some illumination techniques. And we're going to have a little bit of fun with it too. Okay, so the very first technique we're going to talk about is diffuse illumination. So I have my model of an eye, well, I guess about a third of an eye. And just for fun, let's get this eye a pretty nasty looking nuclear sclerotic cataract. And we're going to need our microscope. We're going to need our light source. And this light source is going to be very broad. And it's going to cover a very large area. So diffuse illumination is really great for getting a kind of overview of ocular surface. Like we have a nice view here of what looks like a pseudomonas keratitis from over wear of contacts. Here's a nice look at conch. Here's a nice look at some lids. It looks like those myobobean glands are pretty clogged. And also if we're going to use our blue filter and look at fluorescein uptake, we'll also use a diffuse illumination technique. And that's that. Very easy. We're going to move on to the one that is probably the most popular to use most, the direct focal illumination. So we have our eye. Okay, it looks like you've got that cataract taken care of. That's good. We have our microscope and our light source. And in order to get it nice and thin, we're going to add a few shutters onto it. So we can get a nice thin beam called a parallel piped, or we can go even thinner and get what's called an optical section. So these sort of techniques are going to help us be able to see kind of the cross section through the cornea. So here's a good example of a optical section going through what looks, it's a band keratopathy. You can kind of see how the staining or the light is being reflected off the superior part of this optical section. So that's a calcium deposits in Bowman's membrane. Okay, here's another good example. We can see kind of on the endothelial side, these pigmented pigments. So this is a case of uveitis. And here's a really good one. I wanted to include this one. First time I saw this, I had no idea what I was looking at. You can see the optical section here, and it kind of stops for a second and starts again. So this is a endothelial transplant graph that's actually come separated off of the cornea. And other things we can use our optical section for is we can tell, we can kind of judge the thickness of this cornea. So things like keratoconus, we'll see thinning. And in this example, we see thinning kind of near the limbis. So this would be Tyrion's marginal degeneration. And also if we make our beam nice and short, we can also use this to check for cell and flare. Okay, so let's move on to some of the fancier techniques. It looks like there's a hole in our bag at IOLs falling out the back. Okay, for specular reflection, what we're going to do, take our microscope, put it at an angle, our light source at a different angle, and we're going to bounce light directly off this cornea. So the analogy here is if you're standing on the side of a lake and the sun is shining on this lake and you're looking at it, the lake is completely dark except for that one spot where the sun is reflected right to your eyes. And that's called the zone of... So what that means is when you're looking through a microscope you have your optical section here, and this is the reflection that we've lined up with our optical section that's bouncing right back at us. And what that does is any sort of imperfections you see on that surface of that lake, like a wave, ripple, it will not be bright. You won't see that sun shining back at you. So the same sort of principle we have here where these little divots or gutata from a fuchs distrophy don't reflect the light back towards us. So this is a great way to be able to examine an endothelial layer of the cornea. Okay, retro illumination. So our IOL is completely gone now. We're going to... There's two types we're going to talk about. Iris illumination first. This is where we're going to take light, bounce it off of the iris and back towards the cornea where we're examining. So this is really great for looking at vacuoles of edema in the cornea and as well as vessels growing in the cornea as you can see in this really fuzzy example. Here's another good example of retro illumination from the iris and you can see a tear in decimates membrane. So our other method is what we're going to do, retro illumination from the fundus. So we'll have light directly straight on, going straight back to the eye and it will be reflected from the retina. To get a little bit better look of having the light come towards us we're going to go ahead and dilate this patient and looks like retina is going to go back and try to find that lens that fell out. So this is a great way for grading our cataracts. So we can look to see if there's cortical cataracts, a PSC, a PCO. It's just a really great technique. And also you can look to see if there's any sort of retro illumination of the iris like in this case. This is a case of ocular cutaneous albinism which we'll be hearing about a little bit more next. The next technique is indirect lateral illumination. Okay, they found our IOL. We're going to take a light source and shine it just laterally to our lesion. And what that's going to do is light up the entire lesion for us. So you see that we have retro illumination here, direct illumination here, but this whole thing's lit up. So that's indirect lateral illumination. And this is another example of a Pseudomonas keratitis. Here's another good example of indirect lateral illumination. Ethylial ingrass underneath a weighted flap. Same thing as before, retro illumination right here. Indirect illumination and direct focal illumination. Okay, the last technique I'm going to talk about is sclerotic scatter. So what we're going to do is take our light source at a very strong angle, shine it directly into the limbis. And what's going to end up happening is we're going to have a total internal reflection, just like an optic fiber. So this cornea is going to light up very diffusely, the entire thing. And the only way you'll actually see any light come out of it is there's a lesion that kind of changes this angle so light can actually escape and come to us. So you can see here that we have the whole cornea lit up and you can see subtle corneal opacity that you wouldn't have otherwise been able to see. Here's a good example of a MAPDOP fingerprint dystrophy. And as Dr. Tabin always says, the only thing you really need to remember is the acronym, the LIVNUTE. Do you like a better number one or two? Alright, that's it. Here's some bonus pictures. Here's my two boys and my snow bebo that I made a couple years ago up in Park City. Alright, thank you very much.