 The most important part of any ultrasound examination is to know that you are confident that you examined every aspect of the globe and the orbit. The only way I know to be that confident is to have a systematic exam that I perform in the same way on every patient every time. Certainly, we have specialty techniques for special situations, but the systematic exam will ensure that we perform a thorough examination of the globe and orbit. In order to be clear about where in the eye we're imaging, we need to understand that the mark on the B-scan probe is a very important orientation. It explains to us where on the B-scan the top of the screen is oriented to the mark. So that, for example, if the probe marker were placed nasally to do a horizontal scan, we would have a nasal temporal scan. If the marker were superior, it would be a superior inferior scan. We'll begin by instilling a drop of anesthesia. Would you look up, please? A drop in the closure eye, blot gently. Do not rub your eyes. You have a tissue to blot, but don't rub. Look down. I'll put a second drop. Look way down to your toes. That's it. Did it sting? OK. And we'll start initially of our four quadrant exam with the patient looking superiorly and the farther away the patient can look from where I place my probe, the more anterior periphery I can get with the sound. And that's what we need to see. So I start initially every single one of my transverse scans, either horizontal or vertical, we start by localizing the optic nerve. Once we know we've imaged the posterior portion, the optic nerve, then I will be sweeping the probe so that the superior aspect will be seen. Look way up high for me, please, with both eyes. So the marker is placed nasally. Sometimes you can feel it. You can touch it so that you're sure you're there. Make sure the patient's really looking at 12, not 11 or 10 or one or two. And I place the probe on the inferior limbus and I go straight back towards the optic nerve, which you see right here. Here's the optic nerve shadow. Once I see the optic nerve shadow, then I can sweep the probe. And you see the probe moving down and the sound beam is moving up. Let me go back on the globe. Here we go. And the sound beam moves up until I start to lose contact with the eye and you see the reverberations from the probe membrane. So I've examined the entire superior aspect from optic nerve and the posterior through about the equator, equatorial region, and then way out to the superior until we lose the image quality. Look down to your toes. Now the second exam for horizontal is of the inferior aspect. Marker again to the nose, patient looking down to their toes, place the probe on the superior limbus, localize the optic nerve, see the optic nerve shadow. Occasionally you might need a little lower gain just in order to see that probe shadow more clearly. So there's the optic nerve, so I know that I'm always starting at the posterior. Then I sweep the probe up, but the sound is going down. I'm now at the inferior equator and as I go farther and farther out, I start to lose contact with the globe. So that is the horizontal transverse of superior and the horizontal transverse of inferior. We'll do exactly the same two scans for transverse for vertical. Now the marker will be placed superiorly. I'll add a little more gel. Now I'm going to have you open your eyes and I'll have you look to the left. A little higher, see my finger right here. Most patients don't look where you want them to look when their eyes are open and they certainly have a hard time when the eyes are closed. So that's why the majority of ultrasounds are performed on the sclera unless there's a case of recent surgery, trauma, etc. So now you can see she's looking to the left, she's looking at 3 o'clock. I place the probe vertically on the limbus, temporarily. There's the optic nerve again, so now this is superior, inferior optic nerve and I bring the probe out. There's equatorial and all the way out. In fact, in this case, I get all the way out to her pupil. This is her iris and pupil because I have no nose, no eyebrow, and no bones in the way and in this particular exam plane I can get very anterior. It'll be a lot less in the next. Look towards me please, look right here. That's it, actually just with your eyes. That's it, perfect. Again, the mark is superior. She's looking to the right. I place the probe vertically on the nasal limbus. I localize the optic nerve. Now what's interesting is look how far I had to come to find the optic nerve in this last position. If you think about it, now that she's looking temporarily, the optic nerve which was medial to begin with has now been positioned even more medial. I mean, it's way there. So if I go straight, I won't see the nerve. I have to come a little bit over the edge of the cornea to localize the optic nerve but always start with the nerve. So again, there's the optic nerve and now I bring the probe out this way, you see, going nasally, but the sound beam is being swept temporally, superotemporal, infrotemporal, inferior oblique inserting tendon, medial rectus, so you know I'm equatorial. I go way out until I start to lose contact by seeing the probe echoes from the membrane and now I've examined all four quadrants of the globe in a transverse mode.