 I'll add a little bit more Joe. And when I finished the four basic quadrant transverse scans, the horizontal looking superiorly, horizontal looking inferiorly, vertical looking nasal, and vertical looking temporal, there might be a situation where you need to do an oblique transverse in order to center the pathology in the image. And I'll do an example of an infrared temporal because of the fact that in oncology we see melanomas so frequently infrotemporally. So I'd like you to look down at the shoulder for me. And I'm going to now place the probe, instead of exactly vertically, I'm going to place it obliquely so that the sound now will be infrotemporally. I place the probe superonasally. The probe marker is as up as it can be. And I do the same thing. You start with the optic nerve. There's the optic nerve shadow. And then sweep the probe out, out, out, out. And in fact, this black line right here is the inferior oblique inserting tendon. So you can tell exactly where you are. And now we're to the anterior periphery to get the iris that far out. So occasionally a transverse might be needed. However, I will normally go from my final transverse position of looking temporally immediately to the radial or longitudinal scans. So when I had the marker superiorly, I am now going to place the marker pointing toward the clock hour I would like to image. I would like to image 9 o'clock on her right eye, which is the meridian where the macula lies. So the marker is pointing towards 9. The patient looks at 9. And I place the probe here in the fornex, turn the gain down a little bit. And what you see is the optic nerve at the bottom of every longitudinal scan. So the posterior segment is at the bottom. And the anterior periphery of a particular clock hour is the top. So this is 9 o'clock posterior. Let me show you a little bit more of the nerves you can get oriented. Here's the optic nerve, right, coming into the eye. She has a little teeny elevation. This is the medial rectus muscle, the lateral rectus muscle, the belly, and the inserting tendon. When I have the optic nerve insertion and the lateral rectus inserting tendon in the same view, I know exactly that I'm imaging the macula, because I know that the macula lies on that meridian. Now I'll look at the other meridians with longitudinal as well, if it's a diabetic with a hemorrhage or a high myope with a potential retinal tear. I will look at every clock hour or every one and a half clock hours. But for this demonstration, I'll show you the other three major quadrants. Look straight up now. We're going to look at a longitudinal of 12. She's going to look over the top of her head. The farther away the patient can look from the probe, the more anterior peripheral the sound will get. So now the probe is placed with the marker pointing at 12. So the image will look very similar. Here's the optic nerve at the bottom. We now have superior rectus muscle at the top. So posterior and anterior. That's a longitudinal of 12. Now look to the left. This is a very useful position where there is no eyebrow or nose to limit my mechanical position of the probe. And it allows me particularly in dense cataractous patients to see the entire back of the crystalline lens to differentiate the types of cataracts. So she's looking to the left. And my probe is in the fornix. The marker is pointing to three. So you see how similar these images are? Optic nerve at the bottom where the echoes just stop from the optic nerve shadow. We have the medial rectus muscle, the belly, and the inserting tendon. So we have optic nerve, equator, anterior periphery of three. She does not have a cataract. So we're not even seeing the back of the lens. But let me just take a little peek and see if I can get that for you. There we go. So this is the ciliary body and the pupil and the edge of the iris. And we're not seeing her posterior lens capsule because it's so clear. But that's how anterior periphery you can get with good patient cooperation and with pro position. So now we'll look at the inferior, so looked way down. This will be a longitudinal of six. The marker pointed toward the clock hour being imaged. Optic nerve at the bottom, anterior periphery at the top. And those are the four longitudinal scans. We can do any other ones that we need to. It's very useful to look at the supronazal and suprotemporal areas very, very, very carefully when you have a patient with potentially retinal tears. That's how you'll find a retinal tear. And that covers longitudinal scan.