This Grand Rounds presentation shares a novel intraocular snare technique for the closed-system removal of intraocular foreign bodies (IOFBs) — offering a practical innovation for vitreoretinal surgeons and trainees alike.
OK, the internet's box could be a little bit of a different talk. Um, we're gonna talk about snares, and snares are used throughout ophthalmology. I'm gonna talk about some of the vitrioletinal approaches to um. Removing intraocular foreign bodies, and you know, there's always a lot of drama when an intraocular foreign body comes in. Because there's, there's the mechanism, there's the There's the potential for where this thing is located, there's the concepts underlying the surgical approach, there's the instrumentation, and there's a lot of drama associated with picking the right instrument to physically grasp and remove the object. And so you go to these meetings and There's these dramatic videos of massive things coming out of the eye, and we find that not uncommonly the instruments that we are using to take these things out fail us, you know, you're grabbing the the object and and the object falls back onto the red multiple times. And um So I'm gonna talk about um one of the MacGyver moves that I did a long, a long time ago where there was a gentleman walking through a field and he was shot in the eye where he got a pellet from a shotgun embedded in his eye and it was a very, very heavy, um, metal spherical object that no forcep that we had could grab. And so I, I developed a snare sort of, um, in real time. And subsequently, after being able to do that case, which I don't have on video, um, I, I've been using the snare for forever. And so we're gonna talk about uses for intraocular snares, perhaps a little bit outside of the injury, um, IOP removal in general, and, and talk about the strengths and weaknesses of snare, uh, use for IOL fixation. So, uh, uh, as I said, the snares have been around for a bunch of purposes. Um, I, I did come across this paper where they were using the snare to retrieve and to then fixate, uh, an intraocular lens, um. You know, here, here they're, they're describing the use of this in a 3 piece IOL. In my experience, the haptics on these 3 pieces tend to be easily damaged, and I'll show you just exactly how, how close to home that hits. Um, but here, you know, what they've done is they've created a snare using a needle. They've inserted the needle through the, through the sulcus and lassoed the, the haptic, and then because this snare had a suture remaining on it, they used the, the remaining suture to suture the, the, the suture into the sclera to fixate the IOL. Um, you know, these, these look great on paper and execution can be a challenge, um. Particularly when you're using that two point fixation with a with a basically a loop that's not uh um tied to uh an IOL because you could have. Things slip out. Um, there was a group that developed an intraocular snare, um, like the one we we're gonna be talking about, but this was automated, uses the, um, viscous fluid injection aspiration feature on. arbitrectomy system to Um, push the, uh, pull this up. I think this is a little bit complex and not everyone has, uh, experience, especially in the middle of the night, working with these systems, um, but thought that this was an interesting approach. I personally like the more simple approach that I'm gonna talk to you about momentarily. And then there was a modified flute needle. The flute needle is an ancient instrument that probably was used by the Egyptians during their VR procedures, but I trained with it and it's quite excellent. It is a passive aspiration system that also allows you to inject. Uh, so it, it's, it's, it's a fluid loaded silicone tube that allows you to let go of a, of a small orifice on the handpiece that allows you to passively aspirate blood and passively pick things up, the tissues, um, and if you push on that, that bladder, that silicone bladder, you can puff, uh, so you can get blood away from the area that you're looking for. What they did was they looped the suture through the lumen of the. Uh, of the fluted needle and, uh, and, and the two tag ends came out the, uh, out of that little uh bladder area so that you can pull, pull the snare up. Not everybody has a fluted needle. Like I said, it's a really old instrument. Um, we have them, um, but, but they're, they're gonna be hard to find in the middle of the night. So then we, we wrote a paper in Retna about a nylon snare that that I had described momentarily earlier, and I'm going to present several cases. So this was a case of a gentleman who presented. From a nearby state, uh, who said, you know, my, uh, my eye is changing color. I was at a Halloween party and someone said my two eyes, my irities were different colors. And I don't know if anything was wrong. He could see, um, so it turned out he had a metallic intraocular foreign body that was missed by the retina doctor. They had not done a CAT scan. Uh, and this was, you know, the, uh, the vitreous base, and so you can see I'm just taking a 50 nylon and slipping it into the lumen of a straight cannula. Um, and adjusting the size of the loop. Patience fake it. And just putting a cotton tip applicator. So with 3 items a fibo nylon, a straight cannula, and a cotton tip applicator, we've created our snare. This does require an assistant to pull up on the suture, the tag ends of the suture. So, um, probably one of the hardest things is getting the snare into the eye with a valve cannula, but you can see it's very doable. Um And this patient actually had cirrhosis fall by. His ERG was consistent and uh Uh, what he had was, you know, the, the, the IOFB had hit the back of the eye and bounced off and lodged itself in the, uh, in, in the pars in the vitreous base slash pars planar region. So under scleral indentation, Uh, the loop, which is just nylon, can act as an instrument. You can see I'm teasing it away from the vitreous base, and one of the critical points is that you advance the metal shaft of the straight cannula toward the metallic or whatever uh material intraocular foreign body, or else the snare will just dislodge where it's located. You pull the cannula. Of course this patient's faking, so we're careful to not hit his lens. Um, and then you use a super sharp blade to extend the, uh, the sclerotomy. To an appropriate size. Uh, drama over. OK, so this is another patient hammering metal from pretty close nearby. Um, he, um, Here we are, you can see that the the metallic intraocular foreign body which went through the iris and lens, I believe. It was, it was laying on the surface of the retina. There was a retinal contusion and microscope integrated OCT showed that there was no defect in the retina, so I didn't have to laser this. I I didn't have to do anything. I just had to separate the hyoid, which liberated the foreign body, and then we snared it. And um You can see there's really no drama here. This is very much like the last case. I didn't have to worry about force bumping into the retina. I didn't have to worry about my view. And the other strength of this approach is that the eye is physically closed, meaning I have a, a, a hemispherical cornea. I'm not dealing with a muscle. It It's a well formed eye. I can deal with whatever issues are going on. I don't have to worry about hemorrhage. Here I am hitting the device to demonstrate how firmly adherent or firmly grasped the foreign body is. Once the nylon grasps the foreign body, it remodels itself and it won't let go unless you physically pull the object out of the out of the snare. These things can be reused, you know, if you were, if you make a grasp and you pull up and You know, for some reason you drop it, you can go back down and get it and I'll show you in the last case that that was the case, um, actually advance to the next one. So this was a uh Another faking patient. It turns out he was attacked in a bar fight with a broken bottle and had a massive scleral, uh, cor uh uh scleral laceration, um, with uveal involvement. You can see that nasally and here this piece of glass with the painted. You know, that's the beer bottle, uh, label. Um, you could see that I'm just using the snare to um manipulate the farm by. Of course, I cut this to make myself look really slick as a surgeon. I didn't show some of the other bobbling of the foreign body during the procedure, but you know, it, it, it is an instrument that allows you to orient the, the foreign body into the appropriate orientation. And then one of the key things is advancing the metal cannula toward the far it's as your assistant pulls up on a, on a string. Greg was at Detroit or Rochester. That was right here. OK. So, um, you know, when, when, of course, this is faking, so we're orienting the glass so that it doesn't interact with the patient's lens. And of course, um, one of the key points when removing something from, from the eye is to make sure you're through and through all layers of the eye. So it's real easy to make the scleral incision. But then you have to be particularly careful and make sure that the uh that the that the pars plant epithelium has been incised. You can see I'm going back and I'm incising the pars plant epithelium to then allow my my foreign body to come out. And this is very important in trauma cases because a lot of them have low lying choroidal elevations. And so this suprachoroidal fluid makes it harder. Uh, to, to cut, cut the actual, uh, explain it the thing. Right, when it's tightened, is the assistant constantly? No, it just, it tightens and then you let go. It remodels itself and, and so, you know, your assistant pulls up for you and once it's cinched. Um, it, it's not gonna go, they can let go. It's not a high 10, it's not a high pressure situation where if they let go, it falls back, you know. And when I was Hitting that body on the cannula, there was nobody holding the strings or anything. So for some reason the, the, the, the, I guess the angle that the nylon exits from the uh straight cannula, that angle becomes such that it, it indents the nylon, the nylon remodels and it locks in place. So once it's, once you've got it, you've got it. You don't have to keep pulling. It's a great question. So Ray, one car, you, you had a Q-tip in the back of your cannula. Um, was that repositioned after it's pulled, or once it's pulled, you, you remove it, once it's in the eye, you remove the, the Q-tip to do this maneuvering, and then that doesn't get replaced. That's not part of the tension. No, no, the, the, well, the, the Q-tip is, um, is my handle, is the handle for the device, um. And it does provide, you know, the ability for the nylon to slip through the hub of the needle, and it probably does hold a little bit, but Uh, it's not a critical, I don't think the tension of the Q-tip in the hub is critical, uh, once the, once the foreign body. It's been cinched up. I don't think that that's providing main force for why it holds onto the foreign body. Does that make sense? Yeah, thank you. It helps me to understand that the Q-tip is your handle. I appreciate that. Yeah, it stays on the whole time. Um, and so this was a complex case. I think, I think Sanjay may have said this to me. This is a woman who had a PK, but A terrible uveitis. Her iris was plastered and fused to the post cornea. Um, so there was no anterior chamber. I couldn't do a scleral tunnel, and she had a, um, a, a, a real problem with her vitreous, a lot of inflammation, and she needed a vitrectomy. It was pal. The pupil was small. You'll notice that this lens has no haptics on it. You might ask, well, how did that happen? And that represents the two prior attempts to get this lens out of this eye. OK, so it was a 3-piece IOL and the haptics came, came out, and this, it looks like there's an AC, but there's no AC. And here we just, you know, use the stair through the pars plana, um, to, to pull the optic out. And then, um, you'd see I'm kind of just I didn't even firmly grasp this optic, but you know, I could manipulate the optic on the snare without any major issues. And then, and then I'm going back to, to, uh, to get the tension ring with actually with forceps, but, um, I went for the snare because the view was hazy and it's difficult to judge predimensional depth with a forcep, particularly when you have a small pupil and a hazy view. So I felt it was safer to use the, uh, the snare to physically pull the The optic away from the retina instead of trying to have to get under the optic with one of the tines of the forceps when I didn't have a great three-dimensional perspective. I also had this capsular tetraring in place, which mechanically was confusing the whole, the whole surgical field back there. And we were working over the macula. There was some heel on on the posterior pole to help. Check things, but, um, one of the nice things about the snare, and this is true of the finesse loop as well, I'm gonna show you something related to the finesse loop in a moment. One of the nice things about the snare is that you're not trying to get it tight underneath the fine object and the chance that you're going to transfer force from your forcep through the intraocular foreign body to the retina is much lower because what you're doing is you're, you're lassoing the foreign body. So the only thing that's getting onto the retinal surface is the nylon. And there's no chance that you're going to bump the foreign body with a firm rigid structure. Now once you, once you lasso it, all of the force is being pulled away from the retina, and I think that's intrinsically safer. So this next case, um, uh, is a patient, um, Uh, with retinitis pigmentosa, a patient with Usher's syndrome, who had a really refractory cystoid macular edema, and over the course of my career, I've spent a lot of time studying steroids, and here you can see that I'm using the fast loop. To pick up um the uh You take implant, this patient had associated. You just with cystoid macular edema and he did really well with the first uteique and his after 3 years the uteique wore off. And um I had to do another one, but, but, uh, About a year into his second ute his pressures went very, very high, and we then had to, to remove these uteique implants. And of course, I didn't know which one was the active one, so I removed both, and you can see I stared at it, the action of the of the finesse loop is a little bit janky, and you could see it was the the foreign body was was bouncing as I was withdrawing the finesse. Um, but once we got it, we, we were able to put it, you know, it's a 23, uh, it's actually a 25 gauge diameter. We use this and simply inserted it into the cannula, the valve of the cannula held onto it, and then you could see I inserted the finesse loop into the 23 gauge cannula, and, and we, we were able to externalize. I did that again for the other, um, you. Tee implant. So snares have their role in manipulating these complex shapes in the eye. Um And so in summary, these simple snares can be fashioned with materials that virtually every ophthalmic OR has. This is extremely inexpensive. It can handle, uh, foreign objects that are, that are really odd, like, you know, a perfect circle, um, of, of, of an optic, you know, it, uh, or, or a very abnormally shaped piece of glass. Or a complex piece of metal, um, or a cylinder like a utique implant, uh. So, so I think that this is a, a valid thing and, and, you know, there may be some anterior segment applications for this. I wanted to, uh, to talk about this and, um, explain that this should take away a lot of the drama associated with ILB removal. Doctor Bartley, really clever, uh, technique, Ray. Um, going back to your very first page, the, the first. With the I don't think, um, what was that for buddy? I mean, these are all irregular, so the snares kind of grab them. If you have a shotgun pelt that isn't deformed. Some are deformed, some are not. It depends on what the shotgun can tell us, you know, it's perfectly wrapped. How does the snare work on that? Yeah, that's a great question. It, it was a perfectly spherical foreign body and it was really heavy. It was like literally rolling back, you know. I couldn't grab it with any forcep because the object was this big and my forcep was like this big. And I couldn't get around it. And so what we did was we snared it with, um, that same exact nylon snare and We got it at the equator of the of the of the metal. In fact, I was able to use the stair to roll it away from the macula, and then once it locked, it was, it was, it was there and I got it out of the eye like delivering a baby and then started shaking it. And it wouldn't come off, you know, no one was holding the, the, the, the, the nylon. Yeah, I was shaking to me. I think it was very low. We, what was that's right, yeah. So, um, you know, it was one of those times where we, I just didn't have, have the video, but I had already, I had just fainted away in my mind. And then I had a string of sequential foreign bodies where we did these, and that's how we wound up writing the paper, which was a series of 3. And then when I had this complex IOL, you know, uveitis patient, and I knew I had to take out this lens through the pars plane and the view was bad, I'm like, well, I can use a forcep for sure, but I can see myself, you know, creating an issue. And so I then just use a snare, um. So I think it's pretty versatile. And, uh, it's amazing to think of how things have progressed in the past few decades from using the magnet that was the size of a cantaloupe and sticking it up on the eye and you just turn the thing on and, you know, these metal, metallic things would come blasting out of the eye, causing all kinds of mischiefs on the way. I don't know how much elegant this is. It is super complicated. It's gigantic. It's, you know, you can't control the velocity of the exiting foreign body. Um, then there was the use of pediatric, uh, urology snares, and, um, one time late at night, I, I was able to get somebody, of course, we operate in the pediatric hospital, and, um, I was able to get somebody to find one of these snares, and it was like wrangling a, a snake, you know, it was gigantic, it was rigid. It was a two-dimensional, uh, well, actually it formed 3 there were two snares that formed a 3 dimension. And I'm like, there's no way I'm putting this in the eye. You know, this is like, this is, this is a way too copy. This is a bigger foreign body than the actual foreign body I want to remove. So, um, so I, I think that, you know, when you go to national international meetings about ILPs, there's always a lot of drama about how we grab the thing and the thing falling back. And I think snares are Probably a a a better play. OK. So the question here, which I should have asked in the beginning, what are the advantages and um It's basically all of the Above. Thanks so much for listening.
