Live Surgical Demonstration: Toric IOL Selection and Implantation & MIGS Procedural Techniques

Two live surgical cases will be presented with dialogue between Dr. Kevin Barber and Dr. Hunter Cherwek of Orbis. The first case will demonstrate a combined phacoemulsification and a MIGS procedure. Surgical techniques for the beginner MIGS surgeon will be emphasized and discussed. The second case will demonstrate each step of the Toric IOL process: proper patient selection, pre operative measurements, and marking and implantation of a toric IOL in a phacoemulsification case.

Lecturer: Dr. Kevin Barber, Ophthalmologist, Central Florida Eye Specialists, USA

Transcript

DR CHERWEK: Well, I want to welcome our Cybersight community today. We have an exciting day of live surgery. One of our volunteer faculty, Dr. Kevin Barber, is joining us live from Florida. Kevin, welcome. Tell us a little bit about the day today, and what cases you’ve prepared for us.

DR BARBER: Hey, good morning, Hunter. And good morning, afternoon, or evening to all of you. Globally. It’s great to be here today. As Hunter mentioned, my name is Kevin Barber, I’m an anterior segment surgeon on the East Coast of the United States, in Florida, and welcome to my operating room. I’m very happy to share with you today two great teaching cases. The first case, we’re gonna highlight some pearls for a MIGS procedure, combined with a standard phaco. And then our second case will be a toric intraocular lens case. Back in January, we did a Cybersight surgical livestream, just like today. And in that case, we did a femtosecond laser-assisted digital marking intraoperative aberrometry to do a toric lens. And the feedback that we received was that you, the global audience, really wanted to know more how to implement torics without all of the expensive technology. So you were heard. And so that’s what we’re gonna do today. Today’s case will be a toric, not using the technology. But really emphasizing the fundamentals. And so I’m excited to kind of walk you through that process today, of an entire patient experience with a toric lens. So two main learning objectives today. The first is to make you familiar with the basics of a MIGS Kahook dual blade goniotomy. We’ll show you how to make this an option in your practice. And the second objective is to become familiar with the entire process of a toric patient experience. So before scrubbing, I just wanted to give you a little context. So I’m going to be using an Ingenuity. That is a 3D heads up display here. So you can see the large 3D television here. Our patient is ready to go. To my right, I sit at the 12:00 position. To my right will be Juvee, she’s our excellent scrub tech and mind reader, and over here we have John, our anesthesia provider, who will keep everybody healthy and happy. And so with that, over to you, Hunter. I’m going to go scrub and get started on this case.

DR CHERWEK: Thank you, Kevin. And as always, I really appreciate you taking the time and making the team approach to cataract care. In this case, Kevin has selected a 63-year-old patient with bilateral cataracts. And the patient has mild to moderate glaucoma. Open-angle glaucoma. The patient is hyperopic. Is +3.75 was the best corrected vision, and before surgery, the vision was 20/50 in both eyes. When Kevin did the gonioscopy, there was mildly narrow AC, which we would expect in a hyperope, but he was able to see the scleral spur, 360. The cup to disc ratio was 0.76, and there was early nasal step findings on the visual fields. So when Kevin sat and spoke with the patient and the patient was already going for cataract surgery, he discussed that there was the opportunity to treat the mild to moderate glaucoma with the Kahook dual blade. So Kevin is going to demonstrate that. As we’ve done before in Cybersight, it’s really important to practice in simulation. So if you’re about to start your first goniotomy or combined MIGS case, I strongly recommend that you get some animal eyes or the model eyes, and practice this technique. It’s not simply moving the Kahook dual blade around the anterior chamber. It’s positioning the patient, looking at the gonio lens, and you can practice a lot of that before you ever begin your first MIGS case. So please notice that — and I would strongly recommend, and I’m sure Kevin will talk about — how positioning and using the visualization prism to look at the angle — are very important steps that you can practice on any cataract case, before you go to your first real live patient. So I see Kevin I think is starting the case. Kevin, are you ready to start narrating?

DR BARBER: I’m ready to go. As you can see, we made the paracentesis. Thank you for that, Dr. Cherwek. Okay. I’m gonna give you just a little bit of numbing medication here. So I’m injecting a little bit of non-preserved lidocaine. I do that on all my MIGS cases. Just because we are going to be manipulating the anterior chamber a little more than with the standard phaco. This is my OVD. Dispersive. And then I’ll be creating a clear corneal incision. This is a 2.4-millimeter keratome.

DR CHERWEK: And I liked how you stabilized the wound with the paracentesis.

DR BARBER: Yeah. Lots of different ways to do that. But I’ve become comfortable just using the viscoelastic cannula. That’s just one less time I have to come in there, out of the eye. One less instrument. I have to use. And now I’m performing the capsulorrhexis. Between 5 and 6 millimeters here. Controlled process here, walking the capsule around. And we’ll move on to hydrodissection.

DR CHERWEK: Beautiful.

DR BARBER: Thank you. This is a Chang cannula. I like using the Chang cannula for hydrodissection. It allows me to hydrodissect efficiently. Chang cannula also allows me to manipulate the nucleus and rotate it here. All right. We’ll go on to the phacoemulsification. I’m using an Alcon Centurion unit. My technique — I use several techniques, but kind of my go-to technique is a stop and chop. So I’ll make a central groove. That’s about adequate depth. I’ll go ahead and crack. I’m gonna do kind of a modified chop. Instead of chopping from the anterior segment of the lens, I’ll bring it up. From the posterior. And that just allows me to manipulate that nucleus without causing a lot of stress. To the zonules. And it also allows my phaco needle to just stay stationary in the central safety zone. So I’m not getting myself into trouble.

DR CHERWEK: You’ve done a great job of keeping that phaco needle just at the iris plane and letting the second instrument do the work and rotate.

DR BARBER: When I teach residents, I’m a big advocate of that technique. That instrument can do a lot of manipulation of the nucleus. And keep your phaco needle as central and as stationary as you possibly can. As we get to the end, I’ll place that second instrument underneath my phaco needle. Just because there’s less lens material there to protect the capsule. So it’s on the epinuclear setting. Lower phaco energy, a little bit lower vacuum. I’m happy with that. So we’ll go ahead, switch over to irrigation-aspiration. The soft lens material removal. And I’ve used the C motions, partial circular motions, to strip that cortex again to my central safety zone here. Pieces of cortex there. All right. So as you normally would, I know there are some questions already about — do you do the MIGS procedure first? Or the phaco first? I prefer the phaco first. Yeah. You can do it either way, obviously. But I prefer the phaco first. Now, one thing I’m doing differently here is I’m gonna go ahead and inject more viscoelastic in the angle. Just to begin to open that angle up. Because that’s gonna help with visualization here in just a moment. So this is a monofocal lens. It’s a preloaded lens by Alcon, the AU. OOTO lens. That slides in very nicely. I’ll use my second instrument here just to drop the trailing haptic into the capsular bag. Okay. So we essentially created or finished the phaco portion. I’m now going to prepare for the MIGS. So the first thing I’m gonna do is I’m gonna rotate the patient’s head. So Tom, I tipped your head to the left a little bit, just about 30 degrees. And now I’m gonna rotate my operating microscope also about 30 degrees. And this helps get a good gonioscopy view. So the first real pearl for MIGS procedure is you just have to get an excellent visualization. To really do the procedure well. So the first thing I’m gonna do is put a little extra viscoelastic in, in case I burp some out during the lens insertion. You do not want a soft anterior chamber, because you’ll cause a lot of corneal striae when you’re doing the gonioscopy. Some viscoelastic on the cornea. You can also put it on the bottom of the gonio lens. And then right away, we can see a pretty good view of the angle. So I like that. So I’m going to go ahead and insert the Kahook blade. And I want to take just a moment to focus down to make sure I’ve got excellent visualization. I might mag up just a little bit here. I’m gonna do what’s called an outside-in. You can see this is our trabecular meshwork. I’m gonna go ahead and gauge the trabecular meshwork. And I’m gonna go counterclockwise, and there’s a real feel to this. If there’s not any resistance, you’re probably not fully engaged. If there’s too much resistance, you might have the angle a little too steep. So now I’ve done about two clock hours there. I’m gonna come and now go back in clockwise. And I’m trying to connect my two goniotomies there. And what that does is — if you connect them, you’ll actually amputate these little strips here of the trabecular meshwork. Which is actually what you’re removing. So when I see that strip of trabecular meshwork, it tells me I’ve accomplished my goal. I now have a nice goniotomy performed here. About 3 to 4 clock hours. Oftentimes, you’ll get some reflux of blood. In this case, we don’t have that. And that is essentially my Kahook dual blade goniotomy. All right. So now…

DR CHERWEK: Kevin, that was fantastic.

DR BARBER: Thank you. So now… Again, the real key is visualization. Sometimes it’s not easy to visualize it, as it was in this case. I got a little lucky here. So really the thing I need to emphasize the most is taking the time to get good visualization. That’s the Kahook blade. I wanted to show — there’s three different ways you can do the Kahook maneuver. I’m not gonna talk about those in depth. There’s videos about it. But again, what I did was an outside-in. I started this way, came over here, and started this way, and connected the two right in the middle. The advantage to that is that the strip of trabecular meshwork that you’re excising or removing gets completely amputated here in the center. So that there’s not gonna be a residual tag that’s left in the eye. Okay. So now I’m injecting what’s called trimoxi. This is a compounded medication of moxifloxacin and triamcinolone. It’s compounded by Imprimis Pharmaceuticals. I’ve been doing this for years and it’s worked very well for prophylaxis of endophthalmitis and post-op inflammation control. So I always do that. Now we’ll remove the viscoelastic. I’ll go under the IOL. It’s important to remove the viscoelastic from underneath the IOL. Because it’s common to get postoperative pressure spikes when you do a MIGS case. So you want to make sure… You want to do an extra good job of removing all the viscoelastic. I’m gonna go ahead and go now to my viscoelastic setting, which just has a higher vacuum. I also come all the way over into the angle, if there’s any blood. Or viscoelastic I want to remove that. Again, trying to prevent postoperative pressure spikes. That’s the one thing I really think about, when I do a MIGS procedure. Okay. Finally, I’m gonna hydrate our incisions. This patient — I’ll put on a non-steroidal. We do sometimes see a little bit of extra inflammation, although not much, compared to just the standard phaco. I’m gonna check the pressure, making sure I’m leaving the eye closed to a physiologic pressure. And that’s technically the first MIGS case. So Hunter, over to you, and I’ll be back at the computer in just a minute.

DR CHERWEK: Thank you, Kevin. And I think the key that Kevin demonstrated was pre-op planning. Making sure that he had the right patient for the right procedure. And then he executed that plan. Also, you saw during the procedure how smoothly he rotated the patient’s head. That is something you want to prepare the patient for. So that the patient can cooperate, looking in the right direction, knowing that they may be expected to turn their head from one side to the other. I think the absolute crystal clear thing that Kevin demonstrated was how important your visualization is, before you do a MIGS procedure. And that is, again, something I would strongly encourage anyone who is starting MIGS, to start practicing either in the wet lab through simulation, or on your regular phaco patients, putting the lens on the eye. Getting comfortable practicing to see how the angle opens up and how you can visualize that. You are using both hands, and a lot of people have a learning curve with how to hold that lens, with their non-dominant hand. Kevin, as he said, demonstrated the Kahook dual blade. This is a very popular procedure that’s done for mild to moderate glaucoma at the time of cataract surgery. One of the advantages of doing the phaco first is you open up more space, especially in a hyperope, like what Kevin just demonstrated, so that you’re not worried about dinging or hitting the lens, and also you have a better pathway across the eye. Kevin, you’re ready for your talk. Is that correct?

DR BARBER: Yeah, I’m here. Those are great points, Hunter. You’re absolutely right. That’s why I like to do the phaco first. It creates a lot more space. The only reason I wouldn’t do it is if I’m worried there’s gonna be a lot of corneal edema, or maybe you’re a learning phaco surgeon, and you’re still working on reducing corneal edema, and it could obscure your view a little bit. That’s really the only counterargument for not doing the phaco first. But it is certainly easier. And obviously you’re not going to cause damage to the anterior capsule, or much less likely to, if you’ve already done the cataract, and you have the lens implant in place. So I’m gonna go ahead and share my screen here. And I’ve prepared just a quick… Just kind of a ten-minute talk here about toric lenses. So we’re gonna transition from the MIGS procedure. We will be able to answer some questions at the end of the morning on that. But while my OR staff is turning the room over, bringing our next patient in, I wanted to just give you guys some pearls about toric lenses. Now, this is not a deep dive into toric lenses. There’s so much information with astigmatism management. Our goal is not to cover all of that today. Our goal is, in the next ten minutes, to basically give you the fundamentals. If you’ve never done a toric lens before, or if you’re early on in your toric lens experience, I want to give you some pearls on how to do this successfully. So we’re gonna talk about — we’re gonna do this without having to acquire expensive technology like aberrometers or femtosecond lasers. So let’s talk about identifying the proper patient, how to measure the astigmatism, how to create a surgical plan, how to mark a patient preoperatively, and how to place the toric lens intraoperatively, which we’ll do with the live surgery. So my hope is in the next few minutes, you’re gonna feel a lot more comfortable with this whole process. So patient selection. Obviously you want to pick a patient who has some desire to reduce dependence on glasses or contacts. That’s one of the main purposes for treating astigmatism. About a third of our cataract patients have at least 0.75 diopters of astigmatism or more. I would recommend starting easy. Start with a patient between 1 and 1.5 diopters of astigmatism. As you get into the higher levels of astigmatism, it requires more precision. And more accuracy. So set yourself up for success. Start easy cases, with lower levels of astigmatism. You do want regular astigmatism on topography. You don’t want to start with irregular astigmatism, in cases of, say, keratoconus, or ectasia, or corneal scars. That’s a whole different arena. So stick with regular astigmatism. And of course, you want to avoid cases that could have possible zonular weakness. Maybe pseudoexfoliation, post-traumatic cases, cases where you’re expecting complications. Good dilation is important. Because you’re gonna need to see those toric marks on the lens. So when you’re starting out, do not pick small pupils or patients who have posterior synechiae. And of course, you’re gonna need an intact capsular bag. That’s always a requirement. Let’s talk about measuring astigmatism. There’s lots of different ways to do it, lots of different devices out there. I’m not gonna talk today about which of the devices are better. There’s lots of opinions on that. When I started, I used a manual keratometer, SimKs from a refractor, because that’s what I had. Hopefully you’ll have access to a topographer. That can be helpful. But what I want to emphasize is that I measure with three different devices. This little graph here — this is a real patient chart of mine. I measure each patient that’s going to have a toric lens, with the Verion, Lenstar, and my biometer, and I can quickly compare my three corneal measurements. I want to make sure they agree with each other. Make sure they’re consistent. If you look at the far right, I can see the magnitude of the astigmatism. It’s roughly 2.5 diopters. I’m happy with that. And I can see that the axis is all at 180, 1, and 2. That all lines up. So I feel comfortable putting a toric lens in this patient. Just below that, you’ll also see the stable refraction, and you can see there’s 3 diopters of astigmatism at 180. So a little bit more in the refraction. That could be because of lenticular astigmatism, or posterior corneal astigmatism. Again, those are toric 2b lectures. We’ll get to that on another day. So now you’ve selected the right patient, measured their astigmatism. Now it’s time to make your surgical plan. How do you do that? By the way, the websites, the resources, we’re gonna have that posted at the end of the talk here for you, so you don’t have to feel obligated to write those down now. But if you go to the ACRS website, they have a toric calculator page. It’s open access to anyone. And that’s what I recommend you start using. So you’ll put in your basic information, you can see on the left there your Ks, the axis of your Ks, the axial length. Your ACD. You enter all that information, and it allows you to select which type of toric lens, whether it’s an Alcon or B&L or J and J or Star, you can pick which one you want to use. And then it will tell you where to put that lens. And how strong of a lens to use. Whether it’s a T3, 4, 5, or 6. So all of the math is done for you. So it’s a very simple process of just entering in the information, the data, into one of these toric calculators. Now, each of the manufacturers also has their own toric calculator. Like Alcon is what I showed on the right, and you can certainly use those as well. It is gonna be important that you know what you can treat. So depending on which toric lens you migrate towards, I use Alcon lenses, I’ve used them for years, they have excellent rotational stability. So that’s the one I’m most comfortable using. So I know that I can treat anywhere between 1 diopter, all the way up to about 4, almost 4.5 diopters. Of astigmatism. So you want to be familiar with what the range is. I believe the Bausch and Lomb and Vista goes up to 5.75 diopters of correction inside the US. Outside the US, there are lenses that go up to even higher ranges. So you want to make yourself familiar with what you have at your disposal. So we’ve selected the patient, measured the patient, and we’ve now made our surgical plan. It’s time for surgery. Well, before we can do the surgery, we have to do the preoperative marking. Why? That’s because of cyclotorsion. Any time the patient is laid back into the supine position, the eye has a tendency to cyclotort. So we now don’t know where the true 3 or 9 or 12 o’clock position is on that eye, because it’s rotated. So we need to mark the eye preoperatively. Some of us have digital markers, so we’ve gotten lazy. You certainly don’t have to have one. If you don’t have one, there are several ways you can do it. You can mark an eye at the slit lamp, you can do it freehand, or you can use a handheld toric marker. I’ll briefly show you each of those. These are images of a slit lamp being used to mark the axis. The green that you see is the toriCAM app, a free app you can download on your cell phone, and you can hold it up to the ocular of your slit lamp and see where the slit beam is. Also, most slit lamps, as shown on this video, actually have a toric marker. This is a Haag-Streit type slit lamp. If you have the patient sitting upright, you can put the slit beam on the intended axis of implantation that you got from your toric surgical plan calculator. And then once you have that slit beam centered on the pupil, you can now mark the eye. If you have the slit lamp near your operating room, you can use the marking pen and mark the ends of that slit lamp beam right at the limbus. If you don’t have a slit lamp at your operating center, you could use a 27-gauge needle and make an anterior stromal puncture mark or scratch or mark the limbus. There’s lots of literature out there on different ways of doing this. Now, if you don’t have a slit lamp and you’re not comfortable using that, you can just mark the eye freehand. So the important thing is… This is right before you bring the patient back to the operating room. You want to sit them up in an upright position, you want to have the patient’s head in a neutral position, and you want to have them fixate. I usually have them fixate on my ear. I personally mark the 3 and the 9 o’clock position, the 180 meridian. You can see me doing that here. And it’s fairly easy. You just hold the lids open and have the patient fixate, and you have them sitting upright. Those are the important aspects of that. Now, this is doing the same thing, but now I’m going to use the toriCAM app. And I highly recommend this, because it’s free and easy to use. So again, I have the patient sitting upright, they’re fixating on my ear. I’m marking the horizontal meridian at 0 and 180. Now, did I get it right? Let’s check. So I pull out my cell phone, open up the toriCAM app, and I can use that app to make sure that the marks I made line up. And here I got it at 179. So I’m pretty happy with that. So I’ve now verified that my marks are accurate. You can also use a toric marker. The one here at the bottom is one of the more common ones. You put ink on these marks, and you come at the patient and place those marks, and it’ll mark the 3, 9, and 6 o’clock position. I don’t use these anymore, because I did cause some corneal abrasions, by trying to place this on their eye, and then the patient blinks, and it could scratch or abrade the epithelium. The patients tend to have a little more anxiety when you come at them with a sharp device like this. In the preoperative setting, before they’ve been sedated. So I personally don’t use it, but these are out there. And they certainly can be used, especially with a little practice. Okay. So we have selected our patients. We have measured their astigmatism. Three different ways. Made sure they all agree with each other. We did our surgical planning online, so we know where we’re gonna put the lens and how strong of a toric lens we’re going to use. We’ve now marked our patients, we have our reference point, so now it’s time to actually put the lens in. So what I’m gonna use today is a Mendez ring. I’ve already marked our patient. We’ll see the ink marks there. I’m gonna use this Mendez ring, and you’ll see it in just a moment. On the right is the Cataract Coach, from Dr. Uday Devgan. You can see those marks — they can be used as an alternative to a marking pen. Some of the pearls. You always want to aim for a 5 millimeter capsulorrhexis, because you want the anterior capsule to cover the optic of the lens. If you make a large capsulorrhexis, it’s increasing the possibility of that lens rotating or moving. It also can allow the lens to move more anterior, which can cause a myopic outcome. You usually want to leave the toric about 5 to 10 degrees, just shy or counterclockwise of the final intended axis. Then you’ll remove the viscoelastic or the OVD from behind the IOL. And then you’ll tweak the lens into its final axis. So that’s not mandatory. That’s just a pearl of mine. That’s a technique that I use. It’s easy to rotate the lens this way. Much more difficult to go backwards. So you want to avoid that, if you can. And of course, you always want to keep it in the forefront of your mind that you should abort the toric plan if complications arise. You never want to place a toric lens in the sulcus. Or in a compromised capsule. If that happens, do not put a toric lens in. Go to your Plan B. Okay. Hunter — I’m sorry. One last thing. If you have patients that come in postoperatively, and they still have astigmatism, this is a great resource. Go to astigmatismfix.com. You can plug in all the information, the preoperative data and the postoperative data, and it will tell you if the toric lens is where it should be. It will tell you if it needs to be rotated. So it helps you manage a patient who has residual astigmatism or residual refractive error after a toric lens. Okay. So Hunter, over to you. I’ll let you present the case, while I go and get scrubbed for this next case.

DR CHERWEK: Thank you, Kevin. I think Kevin said a lot of key things that I hope everyone heard. One is preoperative planning. You can see that Kevin measures thrice and cuts once. Also making sure the patient has a good ocular surface. With any of the advanced technology IOLs, the ocular surface is critical. Pretreating any ocular surface disease is very important. Also you can see — throwing yourself a softball. Not having a patient with very complicated case. Small pupils. Pseudoexfoliation, or other zonulopathies are critical as you built your practice and your confidence with the toric intraocular lenses. These are very safe lenses. You can be off quite a bit and still bring benefits to the patient’s astigmatism. So please know that while Kevin is precise, even if you’re off 5 or 10 degrees, you’re still benefiting your patients with these lenses and reducing their spectacle dependence. Kevin talked about patient selection and patient communication. It’s critical for patients to understand that these lenses, like any lenses, are trying to reduce their spectacle dependence. I would not guarantee or say: Oh, you will never need glasses again. Because even with perfect placement, patients may have some spectacle needs or perceive that they need spectacles, especially for up close or near vision, which is not what the presbyopic lenses treat. You can see that Kevin picked a really good case for us. Moderate myope, a -5, and that the patient has no other ocular pathologies. Both with the toric and the multifocal IOLs, you really want to avoid patients who have complex macular disease or other preexisting conditions like Fuchs or other things that may compromise their outcomes, especially while you’re early in your learning curve. One of the things I really appreciate is that this patient is a 3+ NSC, so we’ll see Kevin tackle a dense lens. But don’t let dense lenses prevent you from treating a patient with an AT IOL or dense intraocular lens. These lenses have revolutionized outcomes. Where patients are perceiving cataract surgery as being a refractive procedure, not just a sight restoring procedure. So Kevin’s already marked the patient. This is different from his normal practice, where he uses the digital markers and advanced technology for visualization. But he’s still doing the same pathway with regards to pre-op counseling and patient discussions. For me, that’s critical. You can start your toric or AT IOL journey with minimal equipment, and as you build your practice, add new pieces of hardware or new equipment or new procedures to that. I would recommend with any of your cataract surgeries, but especially once you start new techniques or new technologies, like toric lenses, to keep a surgical log and look at your pre-op and your post-op outcomes. Did the surgical induced astigmatism — SIA — that’s something you’re gonna want to customize for your hands and your practice. So as you start your journey to becoming a refractive surgeon, I strongly recommend that you keep an outcomes log. So that you can compare each patient. What was the pre-op and the post-op refraction? What was the expected refraction? And look to refine any of the variables that can help give your patients the best possible refractive outcome. As you can see from this slide, we are not gonna throw ourselves complicated patients. Don’t do the extreme myopes or the extreme hyperopes. Please don’t have patients with traumatic cataracts or pseudoexfoliation. Where already there is gonna be some challenges with zonulopathies. Or the stability of the capsular bag. You heard Kevin clearly say that every patient should have a Plan B. So that if you’re not able to put a toric lens in the bag, you’re able to have your monofocal ready, and able to put in the sulcus or in another location. I see Kevin is starting. I’ll go hand it back over to Kevin as he puts the ring back on the eye. Kevin, over to you.

DR BARBER: All right. Thanks, Hunter. Great points. All right. So we are… Ready to start. So you can see the reference marks. I just showed you how to make these. The 180 axis. The 3 and 9 o’clock positions. This is a Mendez ring, a cheap, simple thing that any surgeon can obtain. You can put the 180 and 0 mark right on those dots. The intended axis for today’s implantation is 120 degrees. So I’m gonna mark the 120 degree axis. On both ends. And that’s going to be where I implant it. You can do this later. I might come back and do this again. Because the marks could get washed away during the process of the phaco. But I wanted for demonstration purposes to go ahead and show you that. So normally what I would do is make those marks, say, after I’ve put in the viscoelastics. So I’ve taken the cataract out. And I’ve put in my viscoelastic. And I’m about to implant the lens. That’s another time that’s perfectly reasonable to make your toric marks. All right. So pretty standard stuff here. You can see this is a very deep anterior chamber. Much deeper before. So our first patient was a +3. This is a -5. Again, clear corneal incision. Triplanar. Using the 2.4 keratome. You can see the internal lip of the wound here, a straight line. That’s the sign of a good wound that’s going to seal. If it has that chevron incision, it’s not going to seal quite as well. Start in the center. Start my capsulorrhexis again. Wanting to keep that capsulorrhexis roughly 5 millimeters. So it covers the entire optic. To help the refractive outcome and the rotational stability. I would say when you’re selecting a toric lens from the different manufacturers that are out there — one thing you really want to consider is the rotational stability of the lens. There have been some lenses out there, when they first came on the market, that were not as stable. And that’s always… Frustrating. You do a great surgery. You put the lens where you should, and then it rotates postoperatively. And potentially makes the astigmatism worse. You can see the gold ring here. A little hydrodelineation here. The lens now… Really rotating. I like to open my incision with my second instrument, as I bring my phaco needle in. Just to prevent a Descemet’s… Detachment. It can happen right there, at the internal lip of the incision. A couple of passes here, to start a short central groove. Back in place. I’ll go to my quadrant removal setting and start chopping. And here again striving to keep the phaco needle as centrally located as possible. This one is a little bit more dense. High density to it. Keeping in mind I do practice in central Florida. Not in Honduras or India where you have light perception cataracts on a daily basis. Okay. So nucleus is gone. I’ll shift to my epinuclear. Not really aggressive trying to remove epinucleus with my phaco needle. Meaning I’m not gonna go out into the periphery to get all of the epinucleus with my phaco. You can take the epinucleus out with your I and A. If I want to put my capsule at risk. But if the epinucleus will come, like it just did, I’ll take it. Again, I can’t emphasize enough — if you have an anterior capsular tear, posterior capsular tear, you have zonular weakness, dialysis, you really don’t want to put in a toric lens. The rotational stability of the lens would be compromised. You definitely do not want to put the lens in the sulcus. You have to remember — our primary goal is to remove the cataract and restore sight. The secondary goal is the refractive outcome. And it’s important that you don’t confuse the order that our two goals should go in. Removing the subincisional cortex. All right. Fortunately, my ink marks — the 120 — I have… They’re quite visible. Lots of variability in the different sterile ink markers. Some are too thick and they bleed. So I would encourage you to get a fine point or fine tip marker. Some of the ink markers, the ink will wash away very quickly. So you might have to try different types, before you find the one you like the best. So our lens is now in the capsular bag. You can see the toric marks right here. One, two, three dots there. One, two, three dots there. So our goal is to line those dots up with axis 120. Now, there’s still a lot of viscoelastic in the bag. And I’ve got to remove that. You do not want to leave residual viscoelastic or OVD behind the lens. Because that can cause it to rotate. So what I’m gonna do is I’m going to leave a toric lens here. Just a few degrees shy of its final implantation axis. I’m pretty close. But I’m about 10 degrees — I’m about 10 degrees away. All right. Go ahead. I put in my trimoxi, because it’s easier to do that with my viscoelastic and my OVD in. Now I’m gonna stay in my cortex mode. Not my viscoelastic mode. The reason is that the first thing I’m gonna do is go underneath the lens and remove viscoelastic. So I want a lower vacuum, a little more controlled vacuum. So with my phaco machine settings, I prefer to have that on the cortex removal setting, not the viscoelastic. So now the viscoelastic is removed from beneath the IOL. Now I can rotate the lens on axis.

DR CHERWEK: You like to rotate using the phaco tip or the I/A tip?

DR BARBER: You can use the I/A tip. In this case, because it’s a myope, that lens rotates pretty easily. I can also use my second instrument. I think both are acceptable. Hunter, do you have a preference?

DR CHERWEK: No, I’ve seen it both ways. I think what you just demonstrated is great, where you do the majority of the push with the I/A and fine tune with the second instrument.

DR BARBER: Yes, exactly. That’s what I have found, that worked very well. Okay. So now we’ll go ahead and hydrate our wounds. You can see I’ll get a good pressure and form the anterior chamber. And then I’m going to go ahead and do my last adjustment here. And it’s also important that the toric lens is centered. If it’s offcenter, that does affect the toricity treatment. So we do want to make sure the toric lens is as close to the center of the visual axis as possible. Okay.

DR CHERWEK: And I love that you have such nice capsular coverage of the plate. You can see 360 degrees with the 5 millimeter capsulorrhexis. You’re centered. You’re clear. You have complete coverage and stability. And all the OVD is out. That’s as good as it gets, as far as surgery.

DR BARBER: Thank you. So yeah. Great point, Hunter. You really want that capsulorrhexis edge covering the optic. And now I can check my focus down here. You can see the toric marks on the lens. Right here. Right in line with the toric marks. So I’m pretty happy. I’m pretty happy with that. I think we’ll call it a day.

DR CHERWEK: So Kevin, I don’t know if you have any teaching points before we jump into the interactive Q and A. Were there any other points that you encountered in that case that you would like to highlight? Or do you want to jump into some of the questions from the audience?

DR BARBER: Let’s see. Anything that you saw?

DR CHERWEK: No, I think the key is that you did — obviously measuring thrice and cutting once, so you have confidence and clarity in your plan. And I think you did a great job with the OVD removal, so there’s maximal contact with the plate and the bag, so that we don’t have that slippage or rotation that you talked about. So one question we did have… Oh, sorry, Kevin. Did you want to say something else?

DR BARBER: You really touched on something earlier. And that was the… Just really paying attention to the preoperative measurements. Those are critical. You can do the perfect surgery, but if your measurements aren’t right, you’re not gonna achieve the refractive outcome that you want. Also learning to pay attention to things like the anterior surface of the cornea. Patients with dry eye, or maybe anterior basement membrane disease, things like that, are critical. And when you see the keratometric readings not aligning, if the axis is more than 15 degrees off from your different measurements, or the magnitude of the astigmatism is really off, then I think twice about putting a toric lens. Because obviously patients are having to pay more money for a toric lens. Therefore their expectations are going higher. And if I see keratometric measurements that aren’t consistent, and that I can’t really make a solid decision on, then I’ll usually just call that patient back and say — hey, I don’t think we should do a toric lens. I don’t really have a definitive target that I can hit. And I think it’s due to… You know, whatever. So I think that that’s a really important point. Is sometimes we get really eager in wanting to use these toric lenses, as we start to gain some confidence and some momentum. And we end up putting them in patients that maybe we shouldn’t, because we don’t have the measurements we need. So I can’t stress enough how important that is.

DR CHERWEK: Yeah, and you’re fantastic with patient communication, also. Setting the expectations like in the first case where they have to turn their head in different directions. So in the audience, Dr. Kahook was joining today and sent the article about MIGS after phaco. So if anyone was watching, if you look in the chat, that PubMed reference is there. The next is a doctor who was asking: Is your surgical position superior? And do you do phaco through temporal main incision? Is this your routine position and technique? So how do you like to sit for your patients and where do you put your main wound?

DR BARBER: Great question. That’s a fantastic question. I sit at the 12:00 position. I sit at the head. And on a right eye, my incision is at — is temporal. So it’s axis 180. When I do a left eye, I’m coming in over the brow. So it’s a little harder to get to that 180. So I’m really more at 160. And that’s important. Because when you do your astigmatism planner, the online planner, as you mentioned, Hunter, you have to include — or you should include — your SIA. Your surgeon’s induced astigmatism. So any time you make a primary incision, even if it’s a small incision, like a 2.2 or 2.4-millimeter incision, you’re going to affect the astigmatism. It causes a relaxing effect. So on a right eye for me it’s 180. On a left eye, it’s 160. It’s slightly different, because I do sit at the head. So that’s a really important factor to know about yourself. You can go to that same website that I referenced. The ACRS website. And they have a surgically induced astigmatism spreadsheet that you can download. And I think you have to do maybe 50 of your own cases, or you measure the case before and after the surgery. It’s a pretty easy thing to do. And you can come up with your own SIA factor. And then you incorporate that into your surgical planner. Because it definitely can have effects. It does shift. Like in this case we did — her astigmatism was at 115. But the axis of alignment surgically was 120. So why is there a 5 degree difference? That’s because of where I put my incision. So that’s important. 5 degrees isn’t crucial if we’re doing a T3 or small level of astigmatism correction. But if you’re doing a patient who has 5 diopters of astigmatism correction, and you’re using a T9 or a high powered toric, that 5 degrees is going to be more critical. So it is important to look at that.

DR CHERWEK: That’s great. Just like you have to have comfort in your measurements, you have to have comfort ergonomically. Another doctor was asking — going back to the first place, with the MIGS procedure, with the Kahook dual blade, is the KDB disposable? Do you reuse that instrument in your practice and in your hands, Kevin?

DR BARBER: It is disposable. It’s a one-time use here. It’s FDA approved in the US for one-time use. I’m not educated on what that is outside of the US. But I would assume it’s also for one-time use. I will say that out of all of the MIGS devices that are FDA approved here in the US, it is the most cost effective one. It has a very reasonable price point, which I think is why it’s great for global ophthalmology. No matter what economic system you work in. You’re gonna have close to a third of your patients that will have mild glaucoma. And could benefit from a MIGS procedure when they have cataracts. And so making it cost effective is a really crucial point. And some of these MIGS procedures — other ones are very, very expensive. Very cost prohibitive. The Kahook dual blade — one, it works. Two, it’s a fairly easy technical skill to learn. Really the hardest thing is just learning the visualization. Once you learn the gonioscopy view and the visualization, doing the actual Kahook blade is quite easy. It’s not technically challenging. But the icing on the cake is that it is quite affordable. It’s one of the most affordable MIGS procedures out there.

DR CHERWEK: I’m gonna come back to some of the questions about the torics. There’s one more KDB question. What is your preferred KDB goniotomy length? Both how many clock hours — what are you trying to treat? How much of the angle are you trying to treat in these patients?

DR BARBER: That’s a great question. And I might not be as sophisticated as I should be. On that. I think the kneejerk answer is that I get as much as I can safely get. I’m never really worried about hypotony. I can’t remember having a case of lowering the pressure too much. These are typically patients who have pressures above target, and they’re in the 20s, usually. So I will do as many as I can. So I’m trying to get 4 clock hours. Sometimes if I have a very cooperative patient and an excellent view, I can get a little bit more. So if I can, I will. Once I get up to the edge of my view on the gonio lens, I stop. Because I don’t want to be cutting where I can’t see. You can certainly do damage. You can disinsert an iris root or cause a cyclodialysis cleft or something there. So you don’t want to work where you can’t see. So I would say the answer to that is do as many clock hours as you can with good visualization. And usually that’s about 3 to 4 hours. Now, I will also say that there’s newer gonio lenses out there that give a wider view. There’s lots of single use gonio lenses that are being made. So that’s another area that each surgeon — that you can explore. Looking at the different gonio lenses, which might give you a broader or wider view.

DR CHERWEK: I think that gets into the next question, about the… How much is there a risk of both KDB goniotomy, such as iridodialysis and Descemet’s, and I think the risk increases, as you’ve said, where there is a blind pass or not good visualization. In your hands, have you had many complications, or what has led up to any complications you’ve had with the device?

DR BARBER: Yeah. That’s a great question. I appreciate whoever asked that question. Any time we’re talking about a new surgical procedure, that has to be part of the discussion. Right? Or what are the risks? I would say early on, I caused some hyphemas by hitting the peripheral iris. I don’t think that I’ve caused irreparable damage, where I’ve had to go in and fix an iris cleft or something like that. I don’t think I’ve ever caused that. But I’ve certainly gone… The KDB has a tendency to want to go posteriorly, as you advance it. So I did forget to mention that. It does help to kind of angle the KDB up maybe 10 or 15 degrees to keep it in the Schlemm’s canal or in the trabecular meshwork sometimes. Just because of the curvature of the eye. Sometimes it’ll start to dive posteriorly. And if you get into the ciliary body or into the iris root, it’s gonna bleed. And that’s been probably the extent of the complication, is that you have a hyphema that you have to manage in a patient that already has glaucoma. And so that’s just something to be aware of. And some of these patients do get hyphemas. Sometimes it’s because you cause a little trauma to the peripheral iris or the ciliary body. Sometimes it’s just retrograde flow from the collector channels that you just exposed. And so it is quite common to see microhyphema, first postoperative day. So we manage that with a little steroid and we just watch their pressure closely for that. Other than that, yes, you could cause a Descemet’s by going too far up, but again, it all comes back to visualization. Where I see young surgeons get into trouble is where they get some bleeding. They just keep going. And it’s kind of like doing this. And trying to drive down the street. It’s just not a good idea. If you can’t see what you’re doing, stop. You can go in with viscoelastic and try to blow some of the blood away, if they have blood obscuring your view. Sometimes you have an uncooperative patient and you just can’t see the angle. So stop. You know? Do no harm is still our guiding principle that we all learned in medical school. So if you can’t get a good view, I would always say: Stop or just do what you can with the view that you have. But don’t try to go beyond that.

DR CHERWEK: I think that’s a great point, Kevin. Certainly blood can obscure the view, but also tell you that you are where you need to be. You talked about the tactile feel. And that is why the KDB is a single use device. Is those cells that — either blood cells or the trabecular meshwork cells can get in that pocket of that knife. And never be able to be cleaned out. So it certainly is a single use device, but also you want the sharpest instrument, so you have that tactile feel. So that you know exactly where you are and how much pressure you should be applying. We’re gonna switch gears now to go to your second case. How are you with time, Kevin? Do you have time for five or ten more questions? Where are you with your next patient?

DR BARBER: I’m fine. I’ve got another five or six minutes. Fire away.

DR CHERWEK: So one question was: In very high myopes, with the toric lenses, do we aim for the first minus spherical equivalent, or aim higher, to prevent myopic shifts post-op? So A, with very high myopes, how do you potentially calculate or alter the lens implantation? And B, what do you consider a high myope? A very high myope?

DR BARBER: Okay. Great. Yep. So I could be wrong on this. But I think the definition is -8 or higher. Is what we’re considering. You know, higher myopes. The textbook definition. And I think that’s true. Because that tends to be the dividing line from where we start to use maybe different formulas. IOL formulas. Where the effective lens position starts to change, and those kinds of things. So really that question is not just appropriate for toric lenses, but for all lenses. Right? And where it comes… So the point in this is that you have to be meticulous about where you put the toric lens, the axis, and how strong of a diopter or strong of astigmatism correction that toric lens has. But you can’t forget — you still have to do excellent emmetropic work. So if your patient comes out nearsighted or farsighted but they don’t have astigmatism, you still haven’t hit the mark. So that really comes down to how do you — what lens formulas do you use. With a high myope. So what I personally do is: If they’re at 25 millimeter axial length or higher, I also run the Holladay 2 with the Wang-Koch. That’s been shown — you can also use the Barrett Universal. There’s a lot of options out there. I run three different formulas when I have a high myope and usually get three different answers, but that helps me. Sometimes I take the average of those three answers. I might get one that says an 8 diopter, one that says 8.5 and one that says 9. So you’re going to decide: If you’re going to have a little error, would you rather them be -0.5 or +0.5? Usually a myope would rather stay a little myopic as opposed to hyperopic. So I’ll usually have them stay a little myopic. But I encourage the use of multiple formulas when you get to high myopes.

DR CHERWEK: That’s an excellent question. I always say you want to take a long holiday. So Holladay is what I use with those eyes. What is the cutoff point of axis deviation which requires you to go back into the operating room and do it again? In your hands, knowing that everyone is different, their expectations and satisfactions are different, but what numbers make you think… Hey, I just did the Berdahl calculator. I might take this patient back and spin the lens again and see if it gets back in position.

DR BARBER: That’s a great question. I don’t know that there’s a correct… One answer here for that. It depends on several factors. One, is the patient refractively stable? Obviously you can’t make that decision at post-op day one. Probably can’t make that decision in post-op week one. However, if their cornea is clear, the anterior chamber is relatively quiet, and you expect the patient to be seeing well, one week afterwards, but they’re not, and of course you’re doing your refraction… You dilate the patient and you document where the toric lens is. That’s the first thing I do. I’ll dilate the patient and say: Okay. My surgical plan said I should have put this lens at axis 10. I’ll dilate the patient. Okay. The lens is at axis 10. Great. It’s right where I put it. So that shouldn’t be the issue. I’ll still run the Berdahl astigmatism fix just to be sure. Sometimes you put it at axis 10 and they come back and now they’re at axis… You know… 15 or 20 degrees off. That’s probably your problem. So I’ll usually give them another week. And check the refraction and check the lens again to double check. And if they’re not happy, and I have evidence that says if I rotate this lens, I will make them happy, then that’s what I’ll do. You want to do that relatively soon, within probably the first two months of surgery. And that’s not a hard and fast rule. But as you know, the longer that lens is in there, the more capsular fibrosis will happen, which will make it more difficult to rotate that lens. So you want to do that sooner rather than later. So the window of rotating a toric lens starts when you have refractive stability. And it ends when there’s so much capsular fibrosis that you can no longer rotate the lens. And that window of opportunity is gonna be different for each patient. But that’s the way I think about it. I’ve rotated some lenses that were 6 months out. It’s a little nerve-wracking to do it. But sometimes it can be done. But you definitely want to do it earlier on, if you can. I will tell you, it doesn’t happen often. I rotate maybe one or two toric lenses a year. And I do over a thousand of them. So it’s not something that happens very commonly, if you’re doing all of the preoperative measurements. Everything we talked about today. If you’re doing that, that’s gonna keep you from making those mistakes.

DR CHERWEK: I realize you probably only have time for one more question, because you’ve got another patient. There’s four questions about the trimoxi. I think people were very interested in that. Is that what you do routinely? What is the volume? And how does that affect your patient’s post-op drops? Three questions. Is trimoxi your standard of care, what is the volume, and how does that affect their post-op drop schedule?

DR BARBER: Yes. That is definitely my standard of care. I’ve done it exclusively for over 15,000 cases, and I’m a firm believer that it is a really effective way. I’ve had zero cases of endophthalmitis. The treatment for endophthalmitis is an intravitreal injection of antibiotic, which is what I’m doing at the time of surgery. The volume that I use is 0.2 milliliters. So it’s a very small volume. I have a special cannula that’s a shortened cannula, that allows for that transzonular injection. You can also do a pars plana injection. However, I will say this. I do not recommend injecting any compound that’s not being compounded by a certified pharmacy. There’s so many risks to that. There’s lots of risks to that of surgeons doing it themselves or the local pharmacy that doesn’t really do compounding does it, and there’s all different kinds of errors. They put preservatives in it, there’s dilutional errors, and you inject that into somebody’s vitreous, there’s lots of problems. Right? So I only use the trimoxi that’s made by Imprimis, because I trust their quality control. And this is what they do. So I can’t speak for what is available outside of the US. But if you were going to consider it, I think it’s great. Because my patients don’t take drops postoperatively, unless they need a non-steroidal. So my higher risk patients will take a non-steroidal drop if they’re at high risk for CME or inflammation. But the vast majority of my cataract patients are not taking drops when I use the trimoxi. It does affect their vision. They do get some cloudy floaters for a few days. But we warn them about that. We educate the patients that they’re going to have that. But that’s the small price they pay for not having to purchase and to use drops. I think for low to middle income countries, this is an excellent modality. Especially when patients really have barriers to getting drops and taking drops. This is a fantastic solution to that problem.

DR CHERWEK: I think that’s fantastic. I realize we’re going a little over time, Kevin. I want to thank you again for being part of the Orbis family and doing another wonderful demonstration. We’re able to come back from your webinar and talk about the fundamentals of MIGS and toric IOLs. Which I think will only be increasing in usage around the world. I think MIGS are gonna become more and more common throughout the world. And certainly the refractive cataract procedures are increasing globally. I know there’s a few questions that we did not get to. We will answer those in follow-up separately, Kevin. But I want to wish you a good day with the rest of your OR and thank you again. Do you have any parting comments? Christian Becker is on the line, by the way, so you may want to wish him hello in Peru. But are there any comments you would like to say for our audience before we go?

DR BARBER: Yes, just thank you for this opportunity. This is the highlight of my week, for sure. Great to share all of this with you. I hope it was helpful. Christian Becker called me, saying: Hey, will you teach me how to use a toric lens? So this lecture was specifically for him, and everybody else got to benefit too. Anyway, you guys are great. Thank you for the opportunity, Hunter. I really appreciate it, and all that you and Orbis do. You guys are really making a huge difference around the world. Great job.

DR CHERWEK: We’ll follow up on these questions. Thank you again. Kevin, thank you for sharing part of your OR with us.

DR BARBER: You guys have a terrific day. Bye-bye.

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August 31, 2021

Last Updated: September 12, 2022

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