Acquired Astigmatism

Hello, welcome to Eyes for Ears, your Authentomology OCAPs and Board of View podcasts. We're your host Ben Young. And Amanda Redfern. Each week we take a high-altopic and talk about the wine the how. What are we talking about this week, Amanda? So we're going to continue our series on refractive shifts and this time we're going to talk about astigmatism. And again, if you haven't listened to our previous episodes, we're going to do this for oral board-of-view format, so it's going to be pretty quick in terms of the highlights you need to remember if you get an astigmatism case or rather acquired astigmatism case. In your in your oral boards. So we're like to do this in an organized fashion from front to back. Amanda, do you want to take it away with the most interior your cause of acquired astigmatism? Yeah, this week we actually get to talk about the lids. Oh, that's nice. Yeah, right. It's the warranty I've never thought about, but. Sorry, any ocular plastic surgeon out there. In all seriousness, toses. So we think about this a lot in kids who have congenital toses, but it can also happen in adults too where the toses and that lid is pressing against the cornea and causing an induced astigmatism. Along those lines, I mean, any mass on your lid that's pressing against your eye can do a similar thing. Yeah, and I think what maybe a surprising thing might be for more junior residences that even toses is enough kind of pressure or movement along the cornea that can cause astigmatism. And it's important to remember that this can give acquired astigmatism in children because they can then intern and do his amylopia. So that's why it's like a pretty dang important thing to remember with acquired astigmatism in a pediatric population. Next is the cornea just like with the other refractor shifts probably is the most number of reasons. Reasons that in the cornea that you should give a careful example include a tyrigium, solsumous nodules, peripheral corneal degeneration or curatitis like puke, morons disease, and then any any kind of vigtasia. So either a post-surgical one, I add to genetic tasia or other vigtages that we've covered in other episodes like like Curetaconis etc. And then lastly, don't forget that suture-sync cause acquired astigmatism. You know, just a little bit of tension on that 10-0 nylon can induce a pretty reasonable amount of astigmatism. Yeah, I'm pretty sure mine induce astigmatism. That's why I always take those out a little bit of, you know, a couple weeks before I actually do their final refraction after cataract surgery when I have to put a suture in. Yeah, yeah, I do that definitely with my secondary lung cases. I'm like, "Ooh, let's get that this, the suture marker," which I really hope that we nailed the prescription, but you know, isn't what it is. Okay, so the next source is going to be the lens. And as it lens dislocation, it can certainly cause an astigmatic shift, lenticonis, which is that kind of weird outpouching on either the front or the back of the lens. The lens itself can acquire astigmatism, as a cataract is forming, and then lens colabomas. Yeah, I think to remember about lens dislocation is it's not just your native lens that might dislocate with like rectopia lentis, but also mid-neutrachial lens can dislocate. Like if it rotates or tilting, it can give you that acquired astigmatism too from broken designials or whatnot. Oh, it doesn't take much rotation for a torque lens to completely change the astigmatic correction. So decrease what you had intended. Yeah, for sure, for sure. Okay, and then the, probably the most important thing to remember out of all these is going to be to do with the ciliary body. And that'd be a ciliary body melanoma. So again, it's a melanoma, it's tumor, it can be lethal, is a big thing that you don't want to miss. So you want to talk about how you're going to look for lens supplication, it's sectoral cataract, really careful example to take astigmatism, to have a low threshold to to look at the ciliary body with something like a UBM or a anterior segment OCT if they can penetrate that far back. Or at least simply a gonoscopy, or a gonoscopic exam is something that everyone has available in the office no matter where you practice. Some of those machines you may not, but I did find that the most interesting thing about this was the different ways it can cause astigmatism. So like Ben said, the supplication of the lens, sectoral cataract, or clinticular astigmatism, I thought that was fascinating because originally when I heard about this, it's like how on earth? Yeah, yeah, it's pretty wild. And that's like the big thing they're going to want us to know when we're taking our oral boards. Because again, oral birds is like don't kill anyone. Yeah, that's like the biggest thing if you listen to our intro to oral boards episode. Can the redneck cause astigmatism? Well, it's more like, can Ben cause astigmatism? So you know, there's not like even things like foveylectopia, like dragging of the retina, usually doesn't cause like a measurable astigmatism. But just like you're talking about with corneal sutures, you can get astigmatism. If you have a retina surgery and the retina surgeon eluxed you suture your sclerotomies, it is possible, don't ask how I know how, that if you tighten your sutures, you tighten that you can cause astigmatism that way by deforming the sclera. So just if you know, if someone had a vitrectomy and then they have astigmatism afterwards, you can think about that as a possibility. So are you deforming the sclera to the point that it tugs on the cornea? It's like the whole sclera kind of can like infold a little bit. And like that warping of the sclera just four millimeters back can eventually have an effect on the sclera, on the cornea. Yeah, like if you think especially if you make a suture pass that's radial, you know, they need to really talk on, especially if you do that. Like, you know, it really depends on the surgical style, whether you suture radial or circumferential, it has to do with how you, before your sclerotomies to be made. So it's not like the angle that you're sitting at, like, it shouldn't be the angle you should be able to do it both ways. But yeah, it really has to do with the pad, the plainly maker sclerotomy. So, well, I'll leave the sclerotomies to you. Yeah. I wish I could leave the sclerosis or someone else. Anyway, I mean, do you want to go through one more time for review what the causes of a stigmat, acquired astigmatism are? So from front to back, we have lid causes. So either toses or a lid mass pressing on the cornea and warping it. And then of course, the cornea being at the big culprit, we have things like tarigia, salt menogeals, corneal disease, like actasias or ulcerative keratitis, and then, of course, sutures. On the lens side, we have dislocation, linticonis, astigmatism, and colaboma. The big do not miss is the ciliary body mass, specifically the ciliary body melanoma. And then as I just learned today, you can have some issues with sclerotomy closure, where it's a little bit tight, and it can eventually cause some astigmatism. Yeah, they probably won't ask you about that, but you could just keep in the back of your mind, especially if you are a colleague who is also closing sclerotomies. I think you can also technically have one with like, "Tribeck electomies" or something, too, you know? But yeah. Anyways, that's all we have for this week. If you'd like me to be heard, you can follow set eyes for it. 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