Lecture: Cataract Surgery using miLOOP

In this presentation, Dr. Matt Oliva describes about the miLOOP device and also goes through the surgical steps of cataract removal using miLOOP.

Lecturer: Dr. Matt Olivia
Lecture location: on-board the Orbis Flying Eye Hospital in Addis Ababa, Ethiopia


DR OLIVA: So the miLOOP is the first of several devices that he is in the process of developing to try to reimagine what cataract surgery looks like. And he wants to think about the illumination of how we do cataract surgery. Now microscopes are another thing that are hard to deal with. So he’s working on an LED light that goes around the limbus that will retroilluminate and give you a wonderful red reflex without a microscope. And the hope is that maybe someday we’ll be doing cataract surgery even without a microscope, but with special glasses and lower cost solutions that help us reimagine what the procedure is. So as Hunter mentioned, I’ve been here many times. And this is what we all want on our postoperative day one. We want to be like Dr. Allemu was when he was working with Dr. Menepro at Addis Adama Hospital. So we want to feel the joy of our patients and celebrate their vision with them. So maybe the miLOOP is one step down that road for us. So the miLOOP is going around, and it’s a simple device, but it’s a very elegant device. And as Hunter mentioned, the key thing is this metal, which is a type of metal that I don’t know much about. It’s called Nitinol. But it has memory to it. Much like suture can have memory, the metal has memory. And it comes out of the injection device, and you can see it’s shaped exactly like the crystalline lens is. So it’s designed to perfectly have that memory, to go right around the lens. And a thing to note about it is that when it comes out, this actually goes back behind the edge of the injector. So that gets that subincisional cortex. So this is a device that’s designed to break up the nucleus, without having to use phacoemulsification power or to do a manual, having to take it all out in one piece, which is kind of our current options. Basically the narrator here is — I’ll narrate for you — is just showing you the basics of the miLOOP and how it comes out. And this is a single use — designed to be a single use product in the United States — but they’re in the process of making a multiuse product within the next six months. But it has — this is all plastic. It’s pretty lightweight. As you see. And it has basically a toggle here on the track that controls it coming out of the injector. Okay. I’m gonna just skip to a case here. So the first thing I’m gonna do is just show you a whole case. And then I’m going to walk through the individual steps of the case. So this would have been a phacoemulsification case, but it’s with a miLOOP assistance.

>> This is Dr. Farrell Tyson talking about the miLOOP. As you can see, the capsulorrhexis has already been performed. We’re gonna do a general hydrodissection here. Watch. It’s a nice slow wave. Not too aggressive. And maybe tap down the nucleus a little bit. But I’m not rotating the lens. I want to be able to see the edge of the capsulorrhexis. I retract the miLOOP. Enter sideways. And I am horizontal, but aiming slightly down, as I start to extend. Notice the black band around the miLOOP. It’s staying right at the limbus. I slowly rotate. I go past midline in a sweeping motion, and come back to midline to retract. After retraction, I’m able to rotate the lens with the miLOOP. Once I get the initial cut in position, I go ahead and start to extend again. This expands out. It’s a nice general procedure. Now I rotate, go past midline again, come back to center, retract. You notice I may be pushing just a little bit into the eye, keeping the eye from tiddly winking the lens. Now once I’m entering the eye here, I’m able to just go ahead and IA out some of the fluff, and I just utilize segment removal mode to actually levitate the pieces out of the bag. I stay right in the center, at the mid-iris plane, and go ahead and just disassemble the nucleus. This makes it very easy, because the nucleus has already been segmented into four quadrants in this instance. And what you notice is: Look how clear the capsular bag is. The miLOOP has acted like a squeegee, and it actually cleared almost all of the cortex off, making this a very efficient procedure. And it’s also very simple. You probably also noticed that no second instrument was utilized during this, making it a much simpler procedure for all surgeons.

DR OLIVA: Okay. So that’s a very elegant case, with a really dense nucleus that tomorrow is gonna have a very nice clear cornea with a lens in the capsular bag. So I would like a show of hands. How many people here do manual small incision sutureless cataract surgery? Okay, so most everyone. How many people do only traditional ECCE with sutures? Anyone? No? And how many people do phacoemulsification some of the time? No? Okay. All right. So as expected, not a lot of access to phacoemulsification. But if we had asked that question ten years ago, probably everyone would have raised their hands for traditional ECCE. And manual small incision cataract surgery is wonderful. And gives amazing results. However, there are some downsides to manual small incision cataract surgery. One is that you need to make a pretty big wound. I mean, if you’re dealing with a counting-fingers cataract, the external diameter of your wound is probably at least 8 millimeters, and the internal diameter is probably about 10 or 11 millimeters, sometimes. So that’s a big wound that, if you see that patient in a year or two, probably has 3 or 4 diopters of astigmatism from that wound. So miLOOP has a role, I think, to play in a place like Ethiopia, on a couple levels. And I’m gonna get to some examples at the end with doing manual small incision cataract surgery with the miLOOP through a 4-millimeter incision. So step by step, just — they’re gonna be discussing the way it’s done if you’re a right-handed surgeon. You flip it around if you’re a left-handed surgeon. If you’re doing a phacoemulsification, you can do a 2.2, 2.5-millimeter clear corneal incision. If you’re doing it manually, I would recommend a scleral tunnel incision. So the exact same tunnel incision that you make for your SICS. So create your normal capsulorrhexis. So ideally we’re all moving towards doing more continuous capsulorrhexis. You know, Trypan blue is readily available in Ethiopia. It’s not that hard to get. As we’re learning to do our capsulorrhexis, we should be sustaining the capsule and trying all the time to do a continuous capsulorrhexis. However, with the miLOOP, you don’t need to have a continuous capsulorrhexis. It can also be with a can opener. Now, there’s other types of capsulorrhexes too. Some people do V-shaped capsulorrhexis. I tend to do an envelope technique, when I’m doing M6. The miLOOP is not recommended with an envelope or a V-shaped capsulotomy. It should be either a can opener or a CCC. It needs to be a decent sized rhexis. It should be 5.5 or greater. The first thing to do is to do hydrodissection. And if you’re a right-handed surgeon, you’re going to be passing the miLOOP from the right. So it’s better to hydrodissect on the left, so you don’t obscure the view. It’s preferable to hydrodissect and then rotate the lens for a few clock hours, although with the miLOOP, you don’t need to, because it’s gonna really accentuate the hydrodissection process, and that lens is gonna free up, as you’re passing the miLOOP behind it. So obviously you put viscoelastic in, inspect the miLOOP device, to make sure it’s working well. We’ve been reusing them here in Dr. Yonas, Admenolik, and some of the other surgeons. So they can be damaged after a time, so you need to make sure that the device is working correctly. So much like you rotate your — when you’re coming through a side port incision, you would rotate the instrument to allow easy passage, with the miLOOP, you need to rotate it, so that that little loop is perpendicular to the plane of the iris. And the device is — the knob is pulled towards you, so it’s retracted, when it goes into the eye. So this is it with it primarily retracted, and it has a little black mark, as it’s passed around, that you’ll see, that’s etched in with a laser. And the black mark is a guide of where it should be at the limbus. So if the black mark is at the limbus, the tip of the injector cartridge should be right in the middle of your capsulorrhexis. And this is in the plane that’s perpendicular to the plane of the iris. You watch it go underneath the capsulorrhexis. So having Trypan blue is helpful. You don’t want to insert the miLOOP device above the plane of the capsulorrhexis and into the plane of the zonules or you’re gonna completely disinsert all the zonules in the eye. And it slides right underneath, or it wants to go underneath the capsulorrhexis. The key thing is that the miLOOP needs to be fully out of the injector, all the way to the hilt of the control before it is rotated. Once it’s fully out of the injector, it’s just a gentle 90-degree turning of the miLOOP. And it’s slow. But it goes right around and just completes that hydrodissection. And the miLOOP kind of trails for about a second or two behind your wrist. And so that’s one of the tricks of doing it, is that you have to be very patient. And you just kind of slowly turn, and the miLOOP will go right around the lens. So as it’s gone around, it’s cleaved all the adhesions between the capsular bag and the nucleus. And you actually want to pass it all the way out to the equator on the opposite side, and then back to the middle, before you break it in half, and that will allow for complete cleavage, all the way around. So we’ll discuss — that loop sweeps around. So continue past the midpoint, and then bring it back, which they showed in the video. And then the crux of the procedure is breaking the nucleus in half. And you can use two hands, as you see in this picture here. The surgeon is a right-handed surgeon that’s holding it. And then they’re stabilizing it with their left hand. Thank you. So it’s fully out like this. And then this is just pulled towards the surgeon, and it actually has a soft stop, and then it has a hard stop as well. And it’ll cleave 90% of the lens. Although there’ll still be a little bridge of tissue right in the middle. So it cleaves from the outside in, and from the bottom up. It’s cleaving that nucleus. So if you think about the difference between a cracking in phacoemulsification, you’re putting a ton of stress on the zonules as you groove it, and then you break it out. That is very stressful to the zonules. This is not stressful to the zonules, because it’s pulling all that force centripetally into the eye. And the thought is that actually helps with the effective lens position with refractive results as well. One of the challenges is that as you press that nucleus and break it in half, it wants to come up. So you need to refill it with viscoelastic. And there’s two ways of dealing with that. The way I prefer is to use my side port incision. A second instrument. An iris spatula. Whatever chopper, whatever it is that you have. Even a viscoelastic cannula. You can push down on the distal ends of the nucleus, so that as you’re breaking it in half, it doesn’t come up out of the bag. And that’s especially true if you’re doing what we call the MiniCap procedure, which is M6 through a 4-millimeter incision. That chamber is not gonna be as stable as it would be with a 2.2-millimeter incision. The other way to deal with it is that you can kind of push the miLOOP a little bit distally. That helps to keep the nucleus down. I like to use this second instrument. So then it’s broken in half, and then you can spin it again, either with the miLOOP itself or with a second instrument, and then you can cut it and get it into quarters. So with a really hard nucleus, you want to get it into four quarters. Not just a half. And then you just retract the miLOOP back into the injector and it comes out of the eye, and you’ve used zero energy to break up a really dense nucleus. And what’s amazing about the consistency of this metal is that it’ll cut the most hard nucleus that you see in North Wollo region, that’s come in with their light perception cataracts, that have been there for 15 years. This will break any sort of nucleus. And it works well with soft nucleus. It works well with dense nucleus. Anything. So just as another case, and then I’m gonna show you doing it through a manual incision.

>> I was fortunate enough the other day to be able to demo the new miLOOP from Iantech, and I wanted to share one of those cases with you. One of the more routine cataract cases that I’ve done recently. This device here is the miLOOP from Iantech, and what it is is a Nitinol loop on a handle that allows you to expand and contract the loop. And after doing our hydrodissection, I’m placing that loop into the capsular bag, and with a little thumb pusher, you can extend that nitinol loop, and you’ll see that nitinol loop go around the lens. And then with a little twist of the wrist, you’ll see that nitinol loop — there it goes — pass underneath the lens, all the way to the other side. And then we’re gonna rotate back to the center line, and then with your thumb, you can constrict that loop. A little trick here is you also advance the device a little bit, to prevent from rotating the lens up and out of the capsular bag. It basically strangles the lens and cuts it in half, using the loop. And in this case, I decided: Let’s rotate the lens manually by about 90 degrees. And then we’ll go back in with that nitinol loop or the miLOOP one more time. Make sure you’re under the capsular bag. And expand the loop completely. And once again, you’ll see it surround the lens. Once it’s fully expanded, you can rotate your wrist, and it will carefully slide underneath the lens. So here’s that a little bit of rotation. And you’ll see that shadow go all the way across and then come back. And then you can constrict that nitinol loop, and it will once again cleave the lens right in half. So here we’ve been able to fragment the lens into four quadrants, before using any ultrasound energy. You can see here what a beautiful job it does.

DR OLIVA: Okay. So how available are foldable lenses right now in Ethiopia? They’re coming. And I think five years ago, you wouldn’t have been able to get any foldable lenses on the market. But I know now that a PMMA lens in Ethiopia costs about $4, typically. Is that right? Sadik? You would say about $4? I think foldable lenses are between $16 to $18 US? 700 Ethiopian birr. For a foldable lens. So how many patients that come in for surgery ask for phaco in Ethiopia, currently? None?

>> Maybe 50% of the patients now are requesting phaco.

DR OLIVA: So they come in asking for phaco?

>> They ask for ultrasound-based surgery.

DR OLIVA: Okay. So this is a big phenomenon in India. And I think India’s cataract surgery has sort of lagged or has been — Ethiopia, I would say, has lagged behind about 15 years, in terms of the — but Ethiopia will be like India, in terms of — we have so many bright young ophthalmologists who are going out into the setting that there’s more — the economy is growing and people are aging, and they have more disposable income, and they are wanting what any customer of surgery wants. They want high quality surgery. And you’re gonna find that more and more people are asking for either phacoemulsification, which they probably don’t even know what phacoemulsification means, but they know that they want good surgery. They want the best surgery. They want it at a good price, but they want a foldable lens. They may want a lens made in a certain spot. So consumer awareness is going up. So one of the interesting questions is: Can we give the same level of quality as a phacoemulsification surgery without having to own a phaco machine? And that’s really what I think the miLOOP has a niche for. Because if you can give that same wonderful quality surgery, where you’re going through a very small incision — really what patients want is a small incision surgery, I think, in a lot of situations. Especially a 6/18 cataract or a 6/24 cataract that’s coming in. They may not be as happy with MSICS as a counting fingers patient would be, due to the astigmatism. So the patient demand is something that we’re all going to have to address and be cognizant of. So we’ve named this a MiniCap procedure, which is kind of a take on an extracapsular surgery through a small incision. And a 4 millimeter scleral tunnel is, we think, about the right spot. If you have to enlarge for a PMMA lens, there’s probably not a huge advantage to using the miLOOP versus doing a manual small incision surgery. If you have to make a 6.5-millimeter incision anyway to put in the lens, you should probably just do your efficient excellent — take out the lens in one piece surgery. But if you have access to foldable lenses, and you want to cut down on the astigmatism, the MiniCap works very well. So the hardest part is the nuclear delivery, with getting it into four pieces, and then getting those pieces out through the smaller incision. So I apologize for the quality of this video, but it’s about 4 minutes, and it shows a surgeon in Central America doing a MiniCap procedure. So a superior approach, doing cautery to the conj. Making a standard — they don’t show the scleral tunnel, but they make just a standard scleral tunnel that starts 1, 1.5 millimeters posterior to the limbus. The dissection then carries into the clear cornea. It has a decent-sized tunnel, and then enters into the eye. Trypan blue to sustain the capsule. This is a very, very dense nucleus here. But you can still, with Trypan blue, and pericapsulorrhexis forceps, you can do a continuous capsulorrhexis. You can also do a can opener capsulorrhexis. So here comes the miLOOP. So do you think we can get this dense nucleus out through a 4 millimeter incision? Not without something to break it up, for sure. So he’s using the second instrument to hold the lens down when it breaks, so the chamber doesn’t shallow. So he got it into half now. And repeating the break with the miLOOP now into four quadrants. So the material doesn’t get dull. It’s not like you do it once and then it doesn’t cut again. It cuts equally well on the second, third, fourth, fifth pass.

>> Can I interrupt? So what if in case of ectopia lentis? Like in extensive pseudoexfoliations, luxated — zonular dehiscence. Does it really work?

DR OLIVA: It would be better, actually, than trying to do a phacoemulsification with a pseudoex. Because when you’re breaking, you’re putting a ton of stress on the zonules. This puts less stress on the zonules. So pseudoexfoliation level is quite high in Ethiopia, as we all know, so this can work really well. This also works really well with a very small pupil, because it’s scary the first time you put the device around, but once you get facile with it, even with, say, a pseudoex and a really small pupil, you can put this right around there. You don’t need to visualize it. All you need to do is make sure it’s underneath the capsule. If it’s under the capsule, it’s going around in the right spot. And it’s not sharp. The metal is not sharp. So you can see — oh, we missed it. I was talking. But basically all four of those little pieces came right out through the 4 millimeter incision. And the key thing here is that: The one thing that you need is — and there you see the foldable lens coming in. There is an irrigating vectis that — there’s a 3 millimeter one that I’m happy to get anyone in the future that works very well. How many people use an irrigating vectis versus like a lens loop? People use an irrigating one sometimes? Yeah, so if you have one, they’re quite nice. You can hook them up to a bag of saline. You can also use a syringe with saline on it. It helps maintain the chamber. We probably all have delivered nucleuses where, once you pull it out, the entire chamber collapses. And that really dings the endothelium. So an irrigating vectis works quite well with this procedure. It’s not perfect. Sometimes when you have those four pieces, you have to kind of chase it around. Sometimes even with our M6, you have a nucleus that won’t lodge into the wound, and it’s going down, and you want it to come up, and you keep pressing down on the wound to engage it. It’s the same thing with this. There’s a little bit of a learning curve on how to get the pieces out. One trick is — does anyone here use the fishhook technique to deliver the lens? It’s basically when you take a 30-gauge needle and you hook the lens with that, and pull it out in one piece. That can work well with these 4 millimeters. So I think this is a question for the future. For all of you to consider. Especially in the private setting, as many of you will have private practices, in different towns all across this country, can we do these smaller incision surgeries without phaco? And when you’re starting your private practice, spending a lot of money to get a phaco machine is not probably gonna be easy to do right at the beginning. But having the opportunity to do the same quality as phaco, without the phaco machine — and I think this is the other big question: Is there demand for small incision surgery? Will patients vote with their birr? And I think if 50% of people in his practice are already coming and saying they want to do ultrasound-based surgery, they want a small lens, which has happened everywhere else in the world, it’s gonna be exactly the same in Ethiopia, and you’re not gonna be able to get away with doing — on 6/12 cataracts — doing the bigger incision. So I think it has a role to play. And what I want to do is pass around a list, and I want everyone — if people are interested in the miLOOP, we want to start a list of people’s names and people that are starting to do it, and get feedback, as you go out into your career. Because Dr. Anshilav and the team really has focused on Ethiopia and wanting to provide the miLOOP devices and really have you guys innovate with it. Because any new technology really — the demand for it depends on if it helps surgeons and helps patients. So you may find that there’s a better way of doing it than this Miniloop technique, or you may take the device and innovate with it, and that’s really what we hope to see. I would just like to open it up for questions about the miLOOP or cataract surgery in general.

>> What are the main challenges? Any complications using this?

DR OLIVA: The biggest thing that I struggle with is sort of trusting the device right at the beginning. Because it’s really scary to pass something right behind the lens, between the posterior capsule, and you think: Oh my gosh. This piece of metal is gonna rub right against the posterior capsule. The lens is gonna fall on the retina. And I’ve actually never seen that happen with the device. It cleaves that nucleus, and it works wonderfully for that. I think the biggest thing is that when you’re breaking up a dense nucleus through a bigger incision, the chamber wants to shallow, and the viscoelastic — the B&L-made viscoelastic — it is really cohesive, and it comes right out of the eye, and so that chamber wants to shallow. So you need to use your second instrument and hold back the lens and just go slowly, as you’re breaking up the nucleus. So that you don’t push the device up against the endothelium. So really the same tenets that we think about all the time in cataract surgery. Protect the endothelium. Keep the chamber shallow. Go slow and steady. And if the patient is moving — that’s the other thing I worry about. We’ve got a difficult patient. They’re moving around. And your first inclination — and I see this with beginning phaco surgeons too — any time someone is nervous, they want to come right out of the eye. And you certainly don’t want to come right out of the eye if you have the miLOOP in the eye, and that is not pulled all the way in. You would basically pull out the iris, pull out the lens, pull out the zonules. So just don’t panic if the patient is moving in any way.

>> Is there any other comparative study? I know the study from M6 versus phaco in Nepal. So it’s a wonderful idea. MiLOOP with very small incision. So is there any comparative study?

DR OLIVA: So much like we… So for M6, when it first came out, people said: It’s not as good as phaco. And so the way we answered that question is: We had Dr. Sanduk Ruit in Nepal and Dr. David Chang, who is Dr. Cataract, from the United States, came and they went head to head in Nepal, and we looked at the outcomes, and we showed that M6 was not only cheaper, but patients had much better vision on the first day and the six month results were 100% the same. So we’re doing the same type of study at Aravind Eye Hospital, and we’re going to take — with the beginning surgeons and experienced surgeons — randomized patients to either the MiniCap with the miLOOP versus standard phacoemulsification, and also have a third arm, looking at M6, and see what the differences are. And look at endothelial cell counts, postoperative day vision, and we’ll see. And obviously it’s a device that probably has some utility. I use it in my practice at home when I have someone with a really dense cataract. But oftentimes I’ll just do M6 on those patients as well. So there’s probably a niche in there, where it has a role to play.

>> Okay. Do you always release the loop to the full extent when you insert the loop into the posterior aspect of the lens? Because the cataract — there are some cataracts with big diameter and some with small. How do you judge that?

DR OLIVA: That’s a great question. The answer is you always put out the loop to its full extent. So you never underextend the loop. And the capsular bag is big enough and has some give to it that as long as it’s within the bag, it’s fine. But you don’t want to try to make a really small miLOOP and get it around a big lens. That would not work.

>> Other than posterior polar, obvious zonular issues pre-op, are there any contraindications for using the miLOOP?

DR OLIVA: No, I think that’s a great point. If someone has a compromised posterior capsule, it would be a bad choice. Trying to take out the lens all in one piece and do a vitrectomy would be much better. But no, the biggest one — small pupils. It’s wonderful for those cases. So it would be fine in patients that had previous glaucoma or previous corneal surgery. I think it works well in people where — maybe they have trachomatous scars. And a lot of patients in Ethiopia, it’s really hard to see the cataract. And so it would work with those. But in some ways, though, if you have trouble with visualization, it might be — just taking the lens out in one piece would be probably a good choice as well. Yeah. That’s a good point. A shallow anterior chamber, a really high hyperope, patients with prior angle closure glaucoma. Like with any new device, when you’re on your learning curve, you want to pick the cooperative patients, a deeper chamber, a widely dilated pupil, so you can see what you’re doing. You know, set yourself up for success in using the device. Being able to visualize the capsule, I think, could really help.

October 29, 2018

Last Updated: October 31, 2022

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