 Hi, I'm Laura. I'm with the neuroophthalmology department at the Moran. We're going to talk a little bit about how to do an eyelid exam today. Really, all you need is a near card with a ruler or any other way to measure millimeter increments. Okay, so to start out we're going to have the, yeah, we're going to position the patient centrally. Ask her to look down at the end of the room. Typically, the first thing that we look at in terms of eyelid position in neuroophthalmology is whether or not there's ptosis. The way you can measure that is by measuring the distance from the center of the pupil to the lid margin. We call that measurement the MRD1 or the marginal reflex distance 1. So you can hold your near card or your millimeter measurement up, measure from the center of the pupil and then look at right where the margin of the eyelid falls. In order to measure MRD2 or the marginal reflex distance 2, you take that same measurement, but you go from the center of the pupil down to the lower lid margin. And you can do the same thing on the other side. So the MRD1 and MRD2 should be equivalent between the two eyes. You can also measure levator function, which tests the strength of the levator muscle. So again, you ask the patient, yep, you want to center them just like that. Ask them to look down towards the floor with just their eyes. Good. Measure at the lid margin. And now ask the patient to look all the way up towards the ceiling without moving. Good. And you can put your fingers up on the brow to ensure that she doesn't have any help from the frontalis. Good. Look down towards your toes and up towards the ceiling. So you measure the full lid excursion. Generally speaking, normal is about 12 or more. You can also measure the palpebrofissure, which is the distance between the two lid margins. So again, you just hold the ruler right up there in front, measure between the two, measure both eyes and compare. Typical is around 9 to 10 millimeters. We see a lot of patients in the neurophthalmology clinic with myasthenia gravis and a really important test for us is the sustained up gaze test. We look to see if we can induce some or a little bit more ptosis by asking the patient to keep their eyes and up gaze for about 30 seconds. So what you're going to have to do is hold the head still. Ask the patient to look up, up, up towards the ceiling. You can give them a target with your finger and you ask them to sustain that for 30 seconds. It's uncomfortable. It's not easy to do. So it's good to continue to encourage them as they go on. Keep looking up, up, up, up, up, up. I know it's kind of uncomfortable. So we won't wait the whole time, but once you get to the 30 seconds, you want to position yourself directly in front of the patient and ask them on the count of three to look right at your nose. One, two, three. Good. And then you want to look and see whether or not the eyelid has dropped. That will only be effective for like a few seconds. So we also look for the Kogan-Lid twitch, which is a typical exam finding in patients with myasthenia. So you want the patient to look straight ahead. You can either do this after the sustained up gaze, or you can have the patient look down towards the floor and on the count of three, right at my nose. Good. And what you're looking for is you're watching for that eyelid margin to kind of pop up, sort of overshoot and then come back and correct as she returns to primary gaze. Look down, down, down. Look right towards my nose. Look for an up shoot of the eyelid. Perfect. So today we've talked about the eyelid exam and a couple of different exam findings in myasthenia gravis. I hope you found this helpful.