Lecture: Maximizing Surgical Techniques & Best Technologies: Surgical Planning & Potential Post-Op Refinements for Toric Lenses

>> DAVID COOKE: Hello. My name is David Cooke. I’m in Michigan, United States, in the modern section near Lake Michigan, about 60 miles from Chicago. I’m excited today to go over a talk with you about astigmatism. I’m going to share the slide here, share my screen. This is a long title. I have a shorter title. First let me show some disclosures. And let me say that I talk rapidly. Many of you, English is not your primary language, so I had the option to either slow down and talk in monotone or to write it down. I’ve chosen to write most of my things down here. So I’m kind of going to be reading from these slides and hoping that that helps you. My simpler title is “Planning and fixing toric IOLs.” In our title, I’m sorry that we listed that I’ll be discussing the latest technologies. I don’t completely believe in the latest technologies, so I’m not going to discuss those. It may be a little misleading. The ones I don’t believe in so much are the aberrometers that on the table will tell you what the refraction is and so you can fine-tune it, and the American Academy of Ophthalmology has recently released a paper that says that they don’t believe in it either too much. And then the other one would be the systems that allow you to perfectly place the implant according to how you have it intended. And my concern on those is the value, the price versus return for that. And so I’ll start. This is about how to use and especially how to remove toric IOLs. The reason I want to show you how to remove it is, I want to decrease your fear in using these things. You have to know that you have a good backup plan and you can deal with the problem or you’re probably not interested in starting with it. So my goal is to make you experts. And an expert is someone who knows how to get out of trouble once they get in, it’s not someone who never gets into trouble. What’s my target? It would be someone without a lot of experience with premium IOLs, someone’s who understands phacoemulsification, that’s my target, someone who does but does not have access to femtosecond laser or excimer laser, because I don’t have access to it. So I have some questions. What is your health care background? Are you an ophthalmologist, an optometrist, an ophthalmology resident, an ophthalmic nurse, office staff in an eye clinic or an operating room, or other? Wonderful. 55% ophthalmologists. And 17% optometrists. So it’s an educated group that understands ophthalmology and this stuff. I love it. So this actually is some high tech. This is your smartphone. And the article listed down at the bottom was a review, they reviewed a number of articles, and six different toric applications. They felt that the best, according to the literature, the best toric I’ll call it a smartphone application, I guess, the best one was the one on the right there. At the time it was only available on Android. It’s now available on both because I downloaded it last night on my iPhone. And then the one on the left there is the one called the toriCAM. I know it’s available on the iPhone. You line up the marks, and take a picture with this, and it will tell what you the axis is and you can put your marker down and you’ll know what axis you’re starting from. There it tells you the number that it chose. Toric IOLs, I’m a big believer in toric IOLs. There are two big benefits over other premium IOLs. Typically they’re less expensive and I believe the optical quality is beautiful in these lenses. So you can use it in a weird eye, even though it’s a weird eye, because that lens does not have any additional optical compromises. A lens that is going to give you a bifocal or trifocal, it has a lot stray light waves, so it has to compromise something to give you something. The toric IOL patients are the happiest patients. The way I plan to talk about these during this talk, I’m only discussing four toric platforms, the ones that are available here in the U.S. I don’t know a lot about the others. So the names that I’m going to use for this talk are the generic names. T3, T4. And those will apply — like a T3 would apply to an Alcon 1.5 diopter. It would be a 1.5 diopter, and the Alcon would apply to Acrysof and Clareon platforms, which I’ll treat differently in this talk. The J&J, has the same increments. And the Bausch & Lomb, they’re all a quarter of a diopter less but I’ll treat them as if they’re the same. A change in the toric power does not affect the spherical equivalent of the lens. So if the lens is called a 20 diopter lens and it has 1 diopter cylinder, the spherical equivalent is 20. That’s not true with the Zeiss toric IOLs, maybe some other ones, but Zeiss is the only one I know. For Zeiss they treat it like it’s a manifest refraction. A spherical equivalent of 20 diopters in the IOL with one diopter cylinder, actually that spherical equivalent is not 20 as marked on the lens but rather it’s 20.5. I found a very nice table that you might want to look at. I’ve got the reference there for you. And it’s done by Bausch & Lomb, but it’s very helpful. You can click, when you’re done, you click on this. I felt it was nonbiased. And a lot of pictures will come up, pictures of different lenses. And I chose these three, then I clicked the button, open comparison table, and this is what came up. And I circled three things I thought were interesting. It gives you the model number, and you can see on the Alcon, there are a lot of different model numbers. At the bottom it tells you what the power options for sphere, what the range is. I found that helpful because sometimes I go, does this lens come in a 33 diopter or not? So here’s a question I have for the audience. How do you measure axial length in your practice? Optical boo meter, application ultrasound, or immersion ultrasound? 75 percent use an optical biometer. Applanation is not as accurate or is it as precise as immersion. If you’re going to use an ultrasound on a toric IOL, you really want to get the severe correct. You probably should use immersion. That would — there’s information available on that. I didn’t have it for this talk, I’m sorry. So what’s the ideal toric patient? The obvious thing is they have to have money to pay for the lens and they have to have astigmatism. Not so obvious, they need trust and maybe less obvious, the surgeon needs trust. I’m hoping to help you get your best option so when you start, you can have confidence and that will help you and your patients. Let’s imagine you have a patient in front of you. You need to define what success looks like for that patient. Is it, I want a big improvement? If so, might give them high power, you go for high power on those people, T6 to T9. Or the other person says, I want perfect, I want excellent vision in nighttime and never use my glasses for driving. Okay. In that kind of person, you want the lower toric, the lowest astigmatism, T3 to a T5. Now, I did not start with a T2, which is the lowest for many of you, because a T2 is not available in the United States. I assume that’s a FDA thing. I’m not sure. But I’m going to extrapolate from some data that I’ve put together for this talk to try to give you some advice. So again, we’re looking at those, the concept is you want is to big or you want it perfect. Don’t offer your patient both. This is an unpublished study, a veracity database set owned by Zeiss, I’m grateful they let me use this for this talk. They collect their data through an electronic medical records application that doctors all across the U.S. use, many doctors. And this is real world data, so it’s not for a study, and it’s not with perfect conditions. And it’s only FDA-approved lenses because it’s only available in the United States. But it’s a very large data set. In this study I use 30,000 toric lenses. I use 136 IOL models. These are 24 examples of models used in the T3 portion for this study. I lumped them together, and — oh, I should say first, I excluded all eyes with vision worse than 6/6 or 20/20. There were 16,000 I excluded. And then I also excluded the lenses that use the first version J&J toric lenses. There were only 300 of those eyes. And I excluded those because those IOLs were known to rotate. These are all the current IOLs by these manufacturers. Again, there are 30,000 in this study. You can see how many eyes were in each in this data set. Not so many in the T9, the highest powers. That would be these down here. And what I studied was residual astigmatism, after everything was done, compared to the toric IOL power. So here’s the graph. Now, I define success here, for this graph, as the final astigmatism was less than 6.5 diopters. Perfect success would be zero astigmatism, no magnitude at all. But nothing’s ever perfect. And so this is, how did these people do. You see in a T9, success was only about 45%. And each of these lines represents one of these platforms. So all the T9s were lumped together, the blue would be Tecnis, those would be lumped, and the average was put down here, it wasn’t really an average, 40% of them hit the success target. So the reason, if somebody wants perfect, you don’t want to use these higher power lenses, because they’re somewhere around 50 or 60% of the time, they’re perfect. But on the low ends, you get some really high values. I extrapolated — well, let me know you the .25%. I’ll go back and forth. The curve between these, really the slope is almost identical, which is I find interesting, but the T9 on these is only accurate within a quarter diopter for 25% of the patients. However, T3 is up at 60% range. It’s interesting how all of them follow the same curve next to each other. That says to me that these lenses don’t rotate any differently than each other. If one of them rotated a lot, they would have a very low number, low percent here. But you see they hug each other. And then the 50%, .5 diopter is even closer, they hug each other tightly. It was easy to develop a regression formula to see, how would a T2 do? That’s what I have here. T2 is a success 89% of the time. So if you want your patient to be perfect, that patient wants perfect, you want a low power. But are they going to get a big improvement? Unlikely, because it’s only — a T2 only has one diopter in it. If they’re looking for improvement — T9, only 46% were perfect. About half of them ended up perfect. It’s unclear about the improvement. So I studied that a little further, with 86 these eyes, these T9 eyes. And again, remember, they have post-op, all of these have post-op refraction of 20/20, so I trust the post-op refraction. And all of them had 20/40 vision or better initially. So I trust their pre-op refraction. Which does that matter? Because I compared — I looked at those people who had an axis that was greater than 25 degrees off of where they started. Those are the ones that might give you trouble. At least if they have more than one diopter magnitude, and I’ve done a lot of patients with toric lenses, I have a lot of them who have a different axis from where they started, it’s off by a lot. If the astigmatism is a diopter or less, they really don’t complain about it. When it first came out, I was nervous, can I overcorrect this thing, overshoot it by .2 diopters? This group, there were 13% that had an axis greater than 25 degrees and a cylinder greater than 1 diopter so some of these you’ll have to take out or they’ll be unhappy. If my son came to me, I would say, start with a T2 to T4, make sure your initial cases are highly likely to succeed. Do you have access to a topographer, yes or no? Wonderful, 70% do. I’ll tell you some ways to try and avoid trouble, I’ll include that. I wasn’t sure if I should or not. You need to choose wisely if you want success. At the end of the talk, coming soon, I’ll show you about Barrett integrated Ks, that will be coming. I’ll also show you how you can test your own system, your own topographer, your own keratometer, your marking system. I’ll show you how to do that. So you can increase your likelihood of success. This part right here is talking about the Ks, the keratometry. Ks should be fairly symmetric. If you look at your topographer, you’ll see the right eye has astigmatism, steep meridian. Your left one is going to point in this direction. Or they’re straight up but are almost always symmetrical around the vertical axis. Why does that matter? Because if you want one eye pointing at 90 and the other at 45, yikes, something’s — that’s a way you can tell there’s a problem just from your keratometry. Also be aware if K1 or K2 is greater than 50 diopters, because those people are much more likely to have keratoconus. For those of you with typography, a bow tie pattern is good, but use the Ks from your optical biometer, not the Ks from your topographer. They don’t work as well. And of course beware of irregular corneal surface. So this is an example of somebody that does not have a great bow tie, steep on one side, not on the other. My topographer tells me it’s a 37% likely keratoconus. I see this section right here, that central part is where you’re going to look for the bow tie, so I would be cautious about doing a toric on that one. This is a different patient, and you see here they do have a pretty good bow tie. And here it’s a wonderful bow tie. So I would be very interested in using a toric on these. So this one — look at this symmetry here, by the way. You see this one points over about 30 degrees, which is about 60 degrees off of 90. And this one points at about 150, which is about 30 degrees off of 90 in the other direction. And this one is also symmetric but it’s pretty close to 90 degrees for both. But it’s common, like this one is maybe at 92 degrees. And the other one’s at maybe 84 degrees. So just look for that in your Ks. It’s going to help you. But on this one, they’ve got a steep bulge, maybe, down here at the bottom. It makes you nervous about keratoconus. We’re going to talk about how do we adjust things for astigmatism in such a patient. On this patient, I would in a heartbeat do toric IOL on this patient. But if I knew what the posterior curve looked like, these are patient, I love that Anterium for. Same thing with a Pentecam. If you see it’s normal, there’s no bulge, bright spot, hotspot, then just treat it like a normal cornea. To help us with keratoconus, this is not published, I looked at 700keratoconic eyes. I presented this at American Academy of Ophthalmology this week. These are eyes, all of them had keratoconus and the Ks were under 60. And it turned out the best formula for these under 50 was a nonkeratoconic. If there’s a bulge and you’re not sure if it’s keratoconus or not, just use your standard formula and it will cover it for either way. That’s if the Ks are under 50. Again, if access to a posterior cornea, it’s amazing. So keratoconus with Ks over 50 diopter. The best one was the SRK/T, next to it was the keratoconus formula. If you can have the keratoconus measured, that group does the best. So on Lenstar, this is a Lenstar on this particular patient. It turns out it was a very short eye, short eyes commonly have high Ks and the Ks were not greater than 50 so this patient doesn’t bother me about keratoconus even out knowing about the cornea. Keratoconus in general, you overpower the IOL sphere and underpower the IOL cylinder. For sphere, you don’t have to change anything, just use those formulas I mentioned. You don’t have to change your power over or under. For cylinder, you underpower it by two clicks but only if it’s an oblique astigmatism, at least in that group, and there were a lot of Ks there. If the astigmatism is oblique and it calls for a T9, go down two and use a T7. If it’s with the rule and calls for a T9, use a T9. With the rule is defined as a steep anterior corneal meridian, it points up. Against the rule, it points sideways, between zero and 30 and 150 to 180. For oblique, it’s everything else. Here are some eyes, maybe some keratoconus. I would operate on these because you’ve got a bow tie in the middle. Maybe not a perfect one, but enough. This one for sure, in a heartbeat I would do that, they’ve got a lot of astigmatism. We did another study, and this is on our Lenstar, if the standard deviation of the axis was less than 3.5, it was highly likely to do well. I would not choose an RK patient. I have one I’ll show you in a minute, I hope. I had 20 incisions. Currently he’s 2.5 diopters. On that one I did use a toric. But from his perspective, the toric didn’t work. If you have access to an optical biometer, which one is it? And for this, biometer has to use an axial length. IOLMaster 500, IOLMaster 700. There’s some great ways to use the TK values and the PK values. So I’m happy about that. That’s excellent. But that’s for another day. So for astigmatism, I talked about the standard deviation on the Lenstar. Otherwise the IOLMaster was actually better. Pentacam Ks does not do as well as the IOLMaster Ks. Some people had both, they had a topographer and an IOLMaster, which one should they use? Be cautious, reflective keratometry is better. For Barrett integrated Ks, look at that website. Now, you can test your accuracy. We’ll come to that in a minute. Basically you used the Barrett toric calculator, but don’t use a toric IOL, and see how you do. You can increase your likelihood of success if you use good constants, these are IOL constants if you don’t have your own. If you have ultrasound, you can substitute at least immersion ultrasound, you can use it for the same as optical, only up to 25 millimeters. At that point, the ultrasound axial length becomes shorter than the optical axial length and you’re going to start throwing off your sphere. So if you have an ultrasound immersion ultrasound and you have a value greater than 25, you can adjust it with this formula, you can recalibrate it. You take your immersion ultrasound axial length, you multiply it by 1.02 and you subtract .46. And that’s going to give you a value that’s really close to your optical biometer. You only need it for eyes longer than 25 millimeters. Review. Determine your toric goals on a patient. Set expectations according to what’s likely. Look at those graphs I gave you. Avoid perfectionists, avoid problem eyes like refractive surgery, axes that aren’t symmetrical. Test keratometry results. Adjust your immersion ultrasound. Question. I or my surgeon uses or used phacoemulsification at least 70% of the time, less than 10%, or somewhere in between. Oh, wonderful. At least 70% of the time in 70% of the people. So that’s very helpful, for this talk, I got the right crowd here. I’m going to have to go faster because I’m taking too long, I’m sorry. How to repair a refractive surprise after implanting an IOL. Steps to repair a toric IOL surprise. Carefully refract the patient. Identify the axis of the current toric IOL. Those two things matter. Then you’ll enter your data India toric recalculator, I call it a recalculator, like astigmatism fix calculator. Then you’re going to surgically replace it. The most important step is refract your patient who has a toric IOL and it didn’t turn out right. That refraction drives everything. You don’t need another biometer. You don’t need Ks. You won’t use them. It’s the refraction that drives it. Find the axis of the current toric IOL. You do it like this. You’ve got a red image, you can rotate the head, but what if your slitlamp has a head like this like some of ours, and you want numbers like this? There is an article that came out that tells you how to fix that. And I have a little video here of Tom in our office putting one on. And he lines up the 90-degree mark with the notch, the slitlamp is at the 90 degrees, and then puts it on. And you can see as he puts it on, he — it’s just straightforward from that point. And then there is a little light that’s at 60 degrees. And you can test with a protractor how your accuracy is. Now you’re going to enter your data into toric recalculator. Current refraction and the IOL details. There are options for these, four options that we looked at in the study. One is, this one is the one that matters, the Barrett one. I’m hoping that my son and I will have ours up on the Cooke formula. I said that was going to be really soon, three months ago. It’s my fault, I’m hoping I get it to him, hopefully in another couple of months, it will be on that website. So these four toric recalculators were evaluated on 34 patients. Those four items there on the left, those inputs are needed for every formula, for Cooke light, we call it, it only uses those. For all these other formulas, they use a lot more questions, a lot more items like all the preoperative biometry. What if you don’t have that? Or some other questions you may not know the answer to. So this is the Barrett Rx exchange. Here’s how you use it. Up at the top is the name. Then there’s some buttons over there that are active. You see this patient data? When you’re on that screen, right there, you want to use this formula, but you can’t do anything — oh, those are active, you pluck positive cylinder or negative cylinder. Always click the ELP unless it tells you to use the other one, it will tell you to use IOL. You have to enter the patient data before you do anything. Even though you have it entered, you still can’t click that formula. You have to click calculate first. This right here gives you instructions what to do next. So you enter data and calculate. When it says view formula, now you can go up and click that. When you do, then you get your outcome. It has to be in that order or you get stuck. This tells you what to get. Astigmatism fix. Tells you what to fix. The problem is, it asks for some things that are difficult, like what’s the cylinder power at the corneal plane for your IOL? Well, we don’t know that for some IOLs. What was the originally calculated axis? It gives you nice recommendations, however. The main problem with the Berdahl calculator is it only tells what you your results are with rotating. And in our office, I had to take the lens out 34 times and only rotated it once. Cooke-Lite and Cooke K6 are not on the web, hopefully soon. I’ll show you how to replace an IOL here. This is an IOL where I know where it is. I put my ring down at the known mark. And then this one basically was a sphere problem. So I keep the mark almost the same. You don’t have to mark these patients externally before surgery, because you already know where it is. You’ve measured it with the slitlamp. So you put your ring down, if it’s at 133, you put your ring right at 133. Then every number on your ring should be accurate. I’ve marked the axis there. I use a scleral tunnel. Most people probably don’t. So I wanted to just show you how to do this. It’s helpful in some cases. It’s low astigmatism. Theoretically maybe less infection. So I don’t use cautery very often. You’ll see I get blood in my cases but I can keep things pretty clean by wiping the vessels, the spasm. I make a vertical cut in the sclera, about 50%. I come in with the diamond shaped blade. I go parallel to the sclera. As I push it forward, I try not to push forward, I primarily cut from the sides. Why? Because three times I’ve had it slip and one time I went right into the corneal apex and forever she was blurred. It was an older lady who didn’t want a corneal transplant. It wasn’t that bad, but it probably took a line or two from her vision. I go into the chamber. As I put in the viscoelastic, I want to underfill the chamber for two reasons. I’ll skip that. I’ve got a sharp tip here, it’s important that it’s sharp. Pull up the capsule. This is a patient — okay, I pull it up. And I’m going to put viscoelastic underneath there. And this, I use visco, you want one of those viscodisbursive so it can get the capsule back open to its original size. I’ve done this on patients who have had lenses for 19 years, still the capsule opened nicely and did not stick to the lens. You need a pawing motion, like the pawing of a dog to approximately it towards you. If you do, you’ll rip the zonules. So at the same time you’re blowing the sulcus or the equator of the lens bag away from you. So you blow it away and you paw it towards you. You don’t tug it with an instrument or you’re going to rip something. I think I said I’ve done 200 of these and I’ve not yet had the capsule stick to the lens. Now, here I’m grabbing it with forceps and now I’m going to cut it in half. And then I pull the pieces through. See, I pull them through here. Now, this is a different one. This is a light adjusted lens I remove. The toric was being reinserted. The light adjusted lens has proline haptics, they’re very skinny, I just rotated them out. I couldn’t get this new lens to fit. It was stuck. I had tried rotating it, I tried putting in viscoelastic. I already tried to visco-dissect it. It didn’t help. Slow, keep your blood pressure down, don’t move fast, lots of viscoelastic. I released the band I can’t even see, it’s about to release right here. Boing. Now it goes down to the back. These are the instruments. I don’t get anything from them. Those are the ones I use. Key points. Go slowly. Initial underfill the anterior chamber with viscoelastic. Otherwise, use a lot of viscoelastic. It’s your friend. Viscoelastic and time. My pre-op comment to every patient is, I might get in there and see I broke something and feel it’s unsafe for me to proceed, but if I keep things where they are, it will be safe. I tell you that, the patient, to keep my blood pressure down when I’m operating and to keep me from doing something stupid. I don’t want to push too hard. I tell every patient that I haven’t had to use it yet, and you can amputate the haptic and leave it there. The two most important steps are lifting that capsule flap off the anterior IOL with a pointed instrument. You can use a 30-gauge needle if you have to. Again, 200 times, I’ve gotten it. And paw the haptic while blowing the capsule posteriorly. It saves your zonules while you tug those things towards the center. So who was this surgeon? This is a patient with 5.5 diopters of corneal astigmatism. Mono vision in the left eye was for reading. I, the surgeon, did her left eye. She was doing amazingly well, ready for her right eye. When I did her right eye, she came in and said my right eye sucks. I had put the implant at 170 degrees instead of 80. So she started with like 4 diopters, 4.5, and now she has nine because I used a T9. I told her, sorry, we’ll wait three weeks. I want the bag to pull in. Maybe it rotated. I think it was a surgeon problem, but I wanted the bag to contract some so that the next time when I stick it in, it’s not going to rotate. I tell them all, if I have to do it, it’s three weeks. No need to mark the eye, I know it’s at 170 degrees. The IOL easily comes free. You can see the mark right there, this is at 170 degrees. You’ll see the haptic, a little bit of the haptic there. These marks are always at the base of the haptic. There’s the mark. I want to put it up here at 80 degrees. So you’ll see it’s 90 degrees away from where it was. These toric calculators are amazing. She ended up after this, one week she’s 20/20 in that eye without correction. I actually do better if I have to reoperate, I get better results than my normal on the first time, because I know exactly where that axis is, I suppose. I’m not sure. At any rate, I’ve marked it now, I’m going to go in. This is only three weeks out. I’m going to pull up this capsule, but it makes me nervous. You’ll see the lens. I start pointing the capsule down here in a minute with my sharp instrument, down, and the lens moves enough, so I start getting close to the posterior capsule, right there. Uh-oh, that lens is moving on me, I don’t feel I can comfortably get under there and elevate the capsule. So I go to a different spot. The reason it’s like that, normally it doesn’t move like that, but this is a fresh lens. It makes it — the lens moves around a lot more, it’s not solid in there. Three weeks is a great time to take one out if you’re going to take one out. So this one, I lifted it up and there’s enough viscoelastic in the eye, I could get underneath it with my iris sweep. Now I go in with my visco cannula, go in there and blast away. The haptic is going to come toward me by itself, just by blowing it forward, boop, it comes forward. It’s very easy to get these out at three weeks. Then I come from the other side and do the same thing. And as I blow, I try to do a gentle pawing motion, maybe on the optic, maybe on the haptic. Here you’ll see I’m pawing that lens toward me, I’m not tugging it, and I’m blowing the equator away from me while I do that. Now I’ll show you how I rotate, several of you asked about that. It’s simple nudging it. Nothing fast. Slow. I’ll get it until it lines up with that axis. So these are the results of 34 diopter toric IOLs, 34 toric IOLs I exchanged. This is with Cooke Lite. And you want these — I’m not going to explain them, it’s a double angle plat. You want these circles as small as possible, that shows you did well. You want that centroid, the black part, in the middle. It is. So I did well on these 34 eyes. Here’s Cooke Lite, the K6, slightly better, slightly smaller. Here’s the Barrett, slightly worse than the K6, very close. There were 34 eyes. I ranked these by the ellipse area, which is like the standard deviation. K6 was slightly better than the Barrett, slightly better than the Cooke Lite, but all of them are really identical, which means all you really need is your refraction and where the IOL is. We only have one eye that we rotated, so we can use the Berdahl calculator. They’re all the same amount. Now are you ready for the toric calculator? You’re ready to do a case. You put in the patient data, enter the doctor’s name, push calculate. You can now enter measured or predicted. And when you do, something happens. When you push calculate, here’s before you push calculate. Now when you push calculate, it tells you what the astigmatism should be with no toric IOL. You’re going to use this level that I’m pointing at right there, you’ll use that to your advantage. You’re going to test yourself with this. You put in a sphere IOL, I pus the Barrett, it will tell you what prediction you should have for astigmatism. You’ll see how well you do. If you’re spot on, the Barrett calculator worked, and so did your K. So you can test your Ks. In this example, you should have 1.5 diopters of astigmatism and your Ks should be pointing at 119 degrees. This is what I’m really worried about, I want to point out, this is all about astigmatism. Both those are. So you’re going to test yourself and see. The other thing you should do is, when you’re in the OR, I mean, mark the patient, mark them in the pre-op area, and then use your toric marker, and identify where 119 degrees is. Then make a little nick in the conjunctiva. Record your axis, record your astigmatism, make a list of 20 of them, send them in, if we can get Andy to make this work, to Cybersight. Once we’ve got 20 docs who have given a lives 20 each, I’ll try to see if we can get some basic analysis. You’ll need these things. K1, K2, axis for K2, final refraction, and vision type. I need to know the biometer type. And whether your vision is decimal or what type it is. Test your accuracy before you start. Your axis should be ideally at 5 degrees but 10 degrees is acceptable. Your astigmatism should probably be within 0.75. Why not 100? Because the Barrett calculator isn’t perfect. See what axis is most accurate and use that. Typically the axis is most accurate with the rule. So pick with the rule patients. But you’re going to test yourself and you’re going to see. You’ll click toric before, you had just done the calculate, and this is going to tell you what lens to use. And here’s your Barrett integrated case. You click on that spot right there. And then it gives you three options here where you can enter Ks from all three of your calculators. For the actual operation, I didn’t spend much time on this, it’s similar to your standard surgery except the marking part which you’ll figure out. You’ll use your iPhone. Be careful not to put the IOL in the bag even if the bag has a little rupture. I would not do that with toric because you can’t adjust it. Align the toric lens. Remove the viscoelastic under the lens, so that that lens is more likely to stay in position. And make sure the patient is numb when you mark them so you don’t get a Bell’s phenomenon. You have to do it sitting up. You don’t want a new incision on an important case. Remove the viscoelastic. Leave it soft. Some evidence that you should have the patients lie still for an hour afterward. Don’t be afraid to remove or rotate it, only if the bag and zonules are intact. Wait three weeks. Remove Tecnis IOLs. Question. Choose one. I’m planning to test my system without actually using a toric IOL, or I’m beyond that step. Oh, wonderful. Two-thirds are planning to use it. Next clip, this is an IOL that had a 20-incision RK. There was no room for an incision. It turned out to be really helpful to do the posterior corneal — I mean, the limbal — I mean scleral tunnel incision. This one, marking the eye here. I’m going to skip ahead a little. I’ll just skip that one. Question, my toric fears are the same as they were, worse than they were, a little less than they were, a lot less than they were, I have no fear of anything. A little less. We made some progress. A lot less in some, wonderful. Worse than they were in ’16. Sorry, guys. And about the same as they were. Okay. And some have no fear of anything, good for them. May I not be that doctor’s patient. I want my doctor to be a little afraid of something. So next clip, we’ll skip. It was about how if you can’t see the capsule. I do want to show you irrigating under the capsule and how to be certain the IOL is in the bag. So I’m inserting the IOL here, the capsule bag is full of viscoelastic. I can see my inferior haptic. I can see where it went under the capsule there. You can’t see it very well in this video but I know the bag is right there, I know that haptic is in the bag. I always rotate these things until I know this one is also in the bag right here. Even if it’s a small pupil and I can only see in that little area, I move the lens to that little area twice so I can see. And you notice, as I’m moving it, I’m lifting up the IOL so I can irrigate underneath it. And I’m going to show you, this is one more. It’s a small pupil. How do I get under the lens here to irrigate underneath it? So again, I was able to see the capsule edge right there. I put that edge underneath it. Now I’m going to rotate it. So I put the other haptic underneath it. Now, look. I pick up the lens with my visco, I hold the lens up. I put in viscoelastic, so I can take out the viscoelastic. I’m not very aggressive underneath, I’ve got my irrigation port pointing down. I blow down BSS while I’m aspirating beside the lens. And that’s it. Let me go to questions. There are ten questions. Maybe I can get some of these. I will read these. I’m not sure if you can see these questions or not. I want to read through it first. How do I determine the most accurate corneal astigmatism measurement before choosing the toric lens power? So we actually have a program that my son wrote where it takes automatically three different machines’ measurements. And if the sphere and the toric were really close to each other on all of them, it highlights the box green. And I don’t remember exactly what we chose, but probably the degrees had to be within 5 or 10 degrees of each other and the power, the total magnitude of astigmatism had to be probably within .6 diopters. And then it will put a green box. If it’s a little higher, it puts a yellow box. If it’s more than that, I don’t trust the astigmatism, it’s rare that I would do it. Which biometry technologies or formulas do you rely on the most? I think I said that, it would be the IOLMaster, reflective keratometry, the 700, or the Lenstar if standard deviation of 3.5 degrees. Those are the two I have access to. I would probably even use an IOLMaster 500. Test the 500 if you have one, see if it’s good enough. How do you manage discrepancies between topography and tomography? I go with keratometry, I trust the pictures. Do you use intraoperative keratometry? No, I don’t trust it. Let’s see. Oh, I can scroll here. Minimize rotational instability, leave the eye a little soft, have the patient lie still. I use — I do not use a digital system for alignment. With a regular astigmatism, it depends how kooky it is. The one thing in my favor is that the regular astigmatism, the toric lens does not add extra aberrancy to the system whereas a multifocal toric does. If it’s a regular astigmatism, I would not add the multifocality or extended depth of focus. I would just use a pure toric on a regular astigmatism. They asked about toric, can you use toric with an extra cap, in other words you don’t have phaco. And the answer is yes, but you need to know how much your incision affects the astigmatism. My encouragement would be to start with — it depends on whether you do superior or temporal incision. If you’re superior incision, the best thing to do is to just divide your cases into with the rule and against the rule cases, and do 20 of each, and compare what does that Barrett calculator get for astigmatism compared to what you get. If you’re always getting less astigmatism on your with the rule cases, then go down on your toric cases. Toric calculators are different, they ask why. I don’t know why. I’m in the middle of working really hard to get our own. I tell you, the ones I trust, Evo, Barrett, and Pearl DGS. Those do quite well. If I had to pick one right now, I would pick the Evo one. I don’t have the websites for those, sorry. So with the IOLMaster 700, Seth Pantanelli did a study, not exhaustive, using preoperative values. It was using preoperative values and comparing how consistent they were. And he found that TK1 and TK2 were more consistent than K1 and K2. But I’m not sure about using them in a toric calculator. His recommendation is to use those in a toric calculator instead of the Ks. Because he said the results are about the same and your consistency is better. I use Ks in my toric calculations. Do I use phaco in keratoconus? Yeah, but if they have a real thin cornea, I try to avoid the thin spot. Like if they have pellucid degeneration, then I would try — I just did one of those. I would use the toric. One of the issues with toric, if you think they’re going to have a full thickness corneal transplant, I would not use a high toric. If there’s a pretty good chance for a corneal transplant. Because now you’re going to put a new toric in. You might double the astigmatism like I did when I had my lens at the wrong axis. So let’s see. Yeah, the Alcon and Clareon pan optics does not come higher than a T5, someone asked about that. Yeah, so somebody says the IOL’s in the right spot like you predicted, but there’s still a lot of astigmatism after surgery. And so the question is, what do you do? Why was it like that? Well, either your Ks were wrong or this patient has hidden astigmatism. And 15% of patients have posterior corneal astigmatism or astigmatism coming from somewhere that you can’t measure preoperatively. So that’s part of why I feel you need to be able to take lenses out and calculate, okay, I got a surprise. Now that you know the surprise, now you know the right answer. There is no longer any hidden astigmatism, it’s in the refraction, so you can fix it. But you’re going to get it. Either there’s hidden posterior astigmatism or you’re not getting good keratometry or maybe they had really dry eye on the day you tested them and maybe your initial Ks are wrong. What I do on a patient like that is I usually will — I do a lot of stuff. I’ll usually just make sure that I have artificial tears and recheck the Ks, that’s the simplest. So we’re at the end of our time. I’m willing to continue on. I’m hoping if there’s some of these that I didn’t — there aren’t that many more questions. I’ll look through these and try to answer a few more, if you want to stay on. Thank you. I’m incredibly honored, on the preevaluation, there were 137 countries or 136 represented, which is amazing. Let’s see. Yeah, I think definitely you can use toric IOLs with extra cap incisions. But I would probably only do T4, 5, and above. I wouldn’t do it at 1 or 2 — I mean, 2 or 3. On what do I determine the astigmatism on my Ks of the topographer — sorry, on my Ks of the biometer, not on the Ks of the topographer. I did make a different incision based on the axis of the astigmatism. So that’s all part of my calculator. But actually I’ve looked at it, when an incision is back as far as mine is, it doesn’t add much at all, about .1 diopters. Okay. I answered that question already. What do I recommend putting in if temporal incision near the limbus in a three corneal incision? Wow. It would not be much. It would be about a .2. There’s more involved in that. I’m doing a study. I know it’s only about a .2. Thank you very much.