During this 2-hour live surgical demonstration, two phacoemulsification cases were performed with step-by-step narration by the surgeon, who also took questions in real-time.
In this presentation, Dr. Mathur explainss the basics of phacodynamics.
Surgery 1: Phaco Fluidics
Understanding Phaco fluidics improves efficiency and increases patient safety during cataract surgery. This case will demonstrate the basics of fluidics and why and how they are modified during different steps of surgery. The demonstration will be useful for beginner Phaco surgeons.
Surgery 2: Cracking a Hard Nut
This surgical demonstration will discuss preparation, planning and surgical steps in managing hard cataract safely. The live surgery demonstration will allow interaction during surgery and after the procedure.
Surgeon: Dr. Umang Mathur, Dr. Shroff’s Charity Eye Hospital, New Delhi, India
DR MATHUR: So we’re on the Cybersight platform for a demonstration of surgical video, where we’ll be demonstrating fluidics and phacoemulsification, and subsequent to that, we’ll be demonstrating another case, which is slightly hard cataract, how to manage that. I would like to acknowledge Orbis for organizing this webinar. It’s a great platform for learning and sharing. And Alcon, for the phaco development program that they have — it’s a unique surgical training program, where a number of doctors have benefited from the program, and performing phacoemulsification in high volume in various parts of the world. So we’ll be discussing — I thought before we start the surgery, we’ll just discuss a few terminologies that we use in phaco. And before we start, here are a few questions for you. And you have a polling system available for you. The first question is: For chamber stability, irrigation should be equal to aspiration. Is that a yes or a no? So 64% of the participants are saying that irrigation should be equal to aspiration. While 36% disagree with that. We’ll discuss this as we go along. Here’s another question for you. Now, what is surge? Surge is an additional source of vacuum that builds up when the phaco tip is occluded. So there is sometimes a collapse of the chamber as soon as the piece goes in, and that’s what’s surge. Now, how can surge not be prevented? So we have a mixed bag here. The 19% feel that by reducing vacuum settings you will not prevent surge. 31% feel that by using low aspiration flow rate settings you will not prevent surge. 30% feel by using compliant tubings you will not prevent surge, and 20% feel by venting of air or fluid, you’re not gonna prevent surge. Interesting. So we will be discussing this as we go along. And the last question is: What is rise time? Is it the amount of time required for a nuclear fragment to be completely emulsified? The amount of time required to reach a given vacuum preset, assuming complete tip occlusion? Or is it the time that phaco energy is on in a duty cycle in pulse mode? So 91% overwhelmingly feel the amount of time required to reach a given preset vacuum, assuming complete tip occlusion. Very well. So we will be discussing these concepts in this presentation. Now, why is chamber stability so important? Chamber stability is important to provide space to perform phacoemulsification. That’s important to protect the endothelium, the posterior capsule, and iris. If you don’t have space, then all these vital structures — you can do harm to them. Now, the different parameters that we can change in a machine are irrigation — now, irrigation is just the bottle height, and it’s gravity-dependent. If you put the bottle high, you’ll get more fluid, more BSS, into the eye. If you bring down the height of the bottle, then there will be less irrigation into the eye. What is aspiration flow rate? It’s measured in cc per minute, and we’ll discuss that in a minute. And a term which looks synonymous with aspiration flow rate is vacuum, which is measured in millimeters of mercury, and power, which we generally measure in percentage. Now, we just had a question. How do you balance the anterior chamber fluidics? And intuitively, inflow should be equal to outflow, right? And that’s why quite a number of participants said irrigation should be equal to aspiration. However, that’s not correct. Irrigation should be equal or slightly higher than aspiration plus leakage from the wound. So there is always some leakage from the wound, which is desirable. You do not want a very tight wound. So aspiration plus leakage from the wound should be equal to irrigation. In fact, irrigation should be slightly more than that. Now, if you have irrigation less than aspiration plus leakage, one would have a collapse of anterior chamber. And it could be because of more leakage, if your wound size is too large. Or it could be because of high aspiration flow rate settings. Both can lead to collapse of anterior chamber. So it’s important when you set up the machine that the drip-set pinch valve is fully open. There is no restriction to the fluid coming out of the bottle. It’s good to put a needle in the bottle. There should be no kink of the drip-set or the irrigation tubing. Sometimes what happens is that the scrub nurse may want to put a toggle clip or something in the irrigation tubing, and that can actually compress the tubing. So one needs to see that there’s free flow of fluid. And of course, before you start, one must check that the bottle should have adequate fluid, and at no point you should run out of BSS. Some of the newer generation machines have an alarm, and they do let you know that it’s very low on BSS, and it stops functioning, but a lot of machines may not have that. Now, the other thing that sometimes may happen is you may have a puncture in the sleeve. And if you have a puncture in the irrigation sleeve, you’ll have leakage outside the eye, and there’ll be inadequate fluid, BSS, going inside the eye. This is very commonly an error that can happen. Before you go inside the eye, check that your tip is exposed adequately. If too much of the tip is exposed and the sleeve is retracted far behind, it may happen that, while doing surgery, the irrigating ports either go inside the tunnel or it may come outside the eye, and then the fluid will run out instead of going inside the eye, and especially when you’re holding a piece with high vacuum, you may have a collapse of anterior chamber. So the tip should be adequately exposed. Too much of exposure may lead to collapse of anterior chamber. If the incision is too tight, again there’s not enough fluid going in. And it will constrict the collapsible tubing through which the fluid has to go in, and there’ll be insufficient irrigation. The other thing it’ll do is it’ll cause a wound burn. Because the fluid that runs out from the wound dissipates the heat, and it protects the corneal endothelium, as well as corneal collagen at the wound site. Leakage could happen if the incision width is too large, and so one must know what kind of sleeve and tip you’re using. Are you using what is adequate for 2.2? 2.6? 2.8? Or 3.2? Whatever will be the machine and the tip and sleeve that you use, you should be aware of that, so that you use the right size keratome, so there shouldn’t be any leakage. Excessive leakage will cause harm to the fluidics. If sometimes the keratome is a little blunt, or one is not attentive, one can keep creating a tunnel without perforating the Descemet’s membrane, and if the tunnel becomes too long, then there’ll be formation of the wound as you want to go deeper posteriorly to trench. And that could again cause excessive leakage of fluid. Kelman tips are useful. They’re bent and cause less distortion of wound, as the whole probe doesn’t need to angulate too much. So having a bent tip allows visibility. What is happening at the base of the trench. As well as causing less distortion of the wound. Next we come to the other phenomenon of aspiration and vacuum. Now, vacuum is measured in millimeters of mercury and is the firmness with which a fragment is held at the tip. It’s the holding power. Now, sometimes it’s difficult to differentiate it from aspiration. Now, aspiration flow rate is measured in CCs per minute, and it’s the rate at which fragments are attracted to the tip. So whatever fluid and all the loose substances which are in the anterior chamber come to the tip — you don’t go about searching for it in the periphery — the safest zone for the eye is in the center. You’re furthest away from the endothelium, as well as the posterior capsule. And because of aspiration flow rate, things come to you. Very high flow rates of course make the chamber a little more turbulent. And sometimes it can become difficult to control. But flow rate basically is the force of attraction. So vacuum is the holding power, while aspiration flow rate is the force of attraction. Then what is compliance? It’s the collapsibility of the aspiration tubing. So as you generate vacuum, when the tip gets occluded,there’s vacuum in the tubing. Now, that tubing, if it is compressible, it’s compliant. A non-compliant tubing will not compress much when there’s vacuum in the tube. Now, those who use autoclavable tubings over a period of time of several autoclaves, the tubings become more compliant. And so they collapse, and that causes surge. So we had a question: How do you prevent surge? The answer to that is: Compliant tubings. You need to have non-compliant tubings to prevent surge. So when a piece is at the tip, the tubings collapse. As the tip goes inside the tubing, there’s still vacuum, and because there’s no piece at the tip, the chamber collapses at that point. Now, peristaltic pumps — the surge in a peristaltic pump depends on the preset vacuum. If the vacuum is high, you have a higher risk of surge. Now, the greatest risk is when you have the last piece, because you don’t have any cushion below. There’s no piece between the tip and the posterior capsule. And that’s why, when we are eating the last piece, sometimes it’s good to slow down the machine, reduce the vacuum, and reduce the flow rate. Both reduction of vacuum and reduction of flow rate will prevent surge from happening. So you slow it down. And if you have non-compliant tubings, which do not collapse, that would help. Venturi pumps, on the other hand, have only vacuum. They don’t have — you cannot separate aspiration flow rate settings from vacuum. And in a Venturi pump, you have preset vacuum, and it’s all or none, and outflow resistance, which is the internal diameter of the phaco tip and tubings, that determines how much flow rate you get. So generally today most machines have a narrow bore of the aspiration tubing, and a slightly wider bore of the irrigation tubing, so that you have more irrigation and you have less collapse of anterior chamber. Now, coming to another concept of rise time, so we just discussed that vacuum is generated only when the tip is occluded. However, from the time that the tip gets occluded to what is preset as your maximum vacuum, it takes a little time. It is not immediately as the tip touches — is occluding the tip — that you get vacuum. That time is called the rise time. It is the speed with which the maximum value of vacuum is reached, once the aspiration port is occluded. Now, rise time is dependent on aspiration flow rate. The higher the aspiration flow rate, the shorter the rise time. So as you increase the aspiration flow rate, you will generate vacuum quickly, to the point you are wanting it to reach. So vacuum is either zero or it reaches the preset value, but the time it takes to reach the preset value is called the rise time. So why is it important? When you have already chopped the piece, and you want to bring it to the center of the eye to eat or to emulsify, there’s a tendency that you go in a burst of phaco, and you immediately start pulling to the center, and you find that the piece stays there, and the probe comes back. That’s because one has not allowed enough vacuum to get built. So once you have emulsified — used a burst of phaco, go inside the piece, stay there, allow the vacuum to build. Most machines will have a bell, or it reaches a crescendo. Wait for that. And only then start pulling it. And that way, you will prevent that piece from falling. The last modulator is power. Now, power, in conventional phaco, is in a jackhammer effect. It goes back and forth, back and forth, at an ultrasonic speed. So actually, power is a repelling force. So once the piece has broken, it repels and throws pieces away. As you will have seen in a jackhammer drill. The pieces and the stones fly all over the place. That’s what a conventional phaco, which is a longitudinal phaco, does. It’s a back and forth movement of the tip, which throws pieces away. Now, power delivery can be continuous, where there’s no off period, so there’s continuous delivery of power. That does generate heat. Then you have pulse ultrasound, where you have bursts on time and off time. Each of the periods is called a pulse. Here there is a rest time, which causes cooling of the tip, and now most machines have microbursts, which happen at ultrasonic speed, microsecond speed, and cause more cooling. Now, we need linear power when we are sculpting, but when we are emulsifying the piece, we need it in a pulsed manner, because you need the off time not only for cooling. You need the off time so that the piece gets attracted to the tip. If you have linear power, there will be a lot of chatter. The pieces will be flying because of the power, and the vacuum will want to come to the tip, and so there will be a lot of chatter. So the off times allow the piece to come to the tip after it’s broken, so that the piece can be sucked in. So it’s important, when we are eating a piece, when have to emulsify it, after chopping, that you’re in a pulse mode. You can also have a burst setting. In a burst setting, you can have — as you press the foot pedal down, although the power is constant, you will have less and less off time. So if you’re in a very hard cataract, you can actually have — use the burst mode, which is a little quicker, to penetrate into the piece. Or crush it into smaller pieces. These are some of the settings which are generally used. You use low flow rate, low vacuum, and linear power when you’re sculpting. You don’t want the piece to move. You don’t want it to get attracted to you. It’s like when you want to chop a pizza. Or you want to cut a slice of pizza. You first fix it with a fork. Similarly, if it’s moving around, it’ll be difficult to slice it. Similarly, when you’re sculpting, you want things to be stationary. You don’t want the whole nucleus to rock or come to you. So you have low flow rates. Low flow rates — anything less than 20, 22 will be considered low. You want low vacuum. Anything less than 100 in today’s machines would be called low. Basically you want some vacuum. Otherwise the flow rate stops, and there will be wound burns, and also, you want all the flume that comes out to be sucked. And you want linear power. When we are chopping or doing quadrant removal, you will increase the flow rates. Anything above 25 — you can go up to 35 or something, depending on the capability of the machine. You can have higher flow rates. Higher vacuum settings. And one would use a pulse power. When you’re using torsional phaco, we again — while sculpting, one would use low flow rates and low vacuum. And when we are chopping or doing quadrant removal, the flow rates and the aspiration go higher. In the torsional phaco, one of the things that happens is something called — Alcon calls it “intelligent phaco”. You turn it on when you’re doing quadrant removal, because torsional phaco sometimes just makes a hole inside the piece, and that piece can sometimes block the tubing. Also, you need to use the second instrument to dislodge it at the tip, to come out of the drill that the torsional phaco has made. So it gives a burst of phaco. Longitudinal phaco. When it gets occluded. And that helps in getting the piece in, and also presenting the piece at a better location. So coming back to our question, for chamber stability, irrigation is not equal to aspiration flow rate. Irrigation is equal to or a little higher than aspiration plus leakage from the wound. Now, an important concept here is that there is a main incision wound, and you also have the side port wounds. Now, when you’re using a second instrument, if that port is too large, there’s a lot of leakage along with the second instrument. So make sure that your second instrument is not too wide and it doesn’t cause too much leakage, because the machine is designed largely for only the leakage from the main incision. Can surge not be prevented? Well, you can reduce the chance of surge by reducing vacuum, by reducing your flow rate, by venting, which is air or fluid venting that the machines have designed at the tip. There are holes. As soon as the piece goes from the tip, there’s a large amount of fluid. Or in some machines air. That goes out to prevent collapse of anterior chamber. And by using — by not using compliant tubings. So you should not have tubings that can collapse when the vacuum gets separated. Rise time we discussed. It’s the amount of time required to reach a given preset vacuum. So whatever is your preset vacuum, the time it takes from occlusion to preset vacuum is rise time. So I’ll leave you with some of these concepts. And we’ll try to demonstrate these in our case today. So I’ll request Dr. Javid — he will just introduce the case. In the mean time, we’ll get the patient ready. And we would love to have your questions, and please keep writing them down. And we’ll be discussing that after the case.
DR JAVID: Good afternoon, everyone. I’m Dr. Javid. I’m one of Dr. Mathur’s fellows. So our first case today is a 60-year-old gentleman. He comes to us from Delhi. He is unaided visual acuity of 20/200 in the right eye, and he’s got a nuclear sclerosis grade 2 cataract in the right eye. His axial length is 21.83 millimeters in the right eye. His K1 and K2 values are 45.92 and 46.49. The IOL power that we’ve chosen for him today is 23 diopters.
DR MATHUR: So we’re going to be using a 2.75 blade. And this… One could make a limbal or clear corneal incision. I personally like the limbal incisions. And as we all know, one should always enter in front of the root of the iris. And generally, one should not try to… I just like to scratch the conjunctiva a little. Sometimes there’s ballooning otherwise. Just for the sake of demonstration, I will be putting Trypan blue in there. So that becomes a little better visible. I like to make my capsulorrhexis with the help of a cystotome. Now, it’s important to see the direction also of the side port. So depending on at what angle you like to be using your instruments, your side port should be directed in that direction. So if I’m going to be using — like this — I should not be making my side port like this, because otherwise it will cause distortion and more leakage. But two clock hours away is what I like. I’m shearing the flap, with a shearing motion. It is not directed towards the center. Tangentially moving… Low movement. Staying about a clock hour away from the fold. And it’s always good to go beyond the place where you started. So that you have an outside-in closure, instead of an inside-out closure. And again, it’s good not to close in the 12:00-6:00 axis, because that’s the area you will be using a lot of forces. We’re just replacing some… Before hydrodissection… Reduce the amount of visco inside. Now, for hydrodissection, go inside the capsule, lift the capsule up, and with a little jerk, inject. I’m not too happy with the wave I got. I’ll try another. And when you see a lift in the nucleus, generally that’s the time to stop, and then you burp it a little. I’m doing a little delineation, and I can see some delineation happening. You can see the edge over here. So the idea with the hydrodissection is that you should be able to move the nucleus. So that you can attack it from different angles. At this point, I like to coat the endothelium, and the preferred viscoelastic would be a dispersive viscoelastic. This is the DuoVisc, which gives work space, as well as… Now, sometimes what happens is that you may not get a very good wave, and you may not be totally happy with your hydrodissection. Now, it’s not something that has to be done only now. By creating a little space, after trenching a little, if you find that your nucleus is not rotating well, you can always go back, and at that point, you will be able to do the hydrodissection well. Now, before you introduce your probe inside, it’s important to see how much of your tip is exposed. So this is adequate, and your irrigation port should be on the side. So the irrigation should not be facing up or down. It should be on the sides. And this is the bevel. You’re using a 45-degree tip. A 45-degree tip has very good cutting. But you need to go inside the tip much more. Inside the nucleus much more, to generate vacuum. Because it will get occluded only when all of this has gone in. So a 45-degree tip is good for cutting. Especially in harder cataracts. But it will take more time to generate vacuum. A 30-degree tip, on the other hand, will be easier in generating vacuum. A 50-degree tip will generate vacuum very well, but cutting action would not be that good. So that is how you choose. One of the ways to generate vacuum with a 45-degree tip is: Instead of doing it at 6:00, you can do it at an angle, say between 4:00 and 5:00. So there, instead of burying the whole tip, you just — you don’t have to bury it all the way in. You get a large surface area to occlude. And that way, you get a good seat. So we always go inside the eye. With irrigation on. Whenever the probe is inside, the irrigation should be on. So we are aspirating the superficial cortex. We make sure that we are well focused. So as you can see, the settings — we’re using longitudinal phaco here. We’re not using torsional. We’re using linear phaco. At this point, my foot pedal is at step 3. As we go down, I’m widening the trench a little. To accommodate my tip. And now I can start seeing the red reflex. At this point, I feel that I have adequate depth, and I can crack the pieces into two. And I would like to position it so that I can attack it better. So if you can see the setting at this time, now we are in pulse mode at a higher flow rate and a higher vacuum of around 400 millimeters of mercury. Flow rate of 36. Right? And pulse phaco. So my intention now is to chop. So to chop, I need to first generate vacuum. To generate vacuum, I will go inside the piece with a burst of phaco. Now it’s sufficiently… Now I’m waiting for rise time. So now I have complete vacuum. My second instrument, which is basically a Sinskey, goes towards the optic nerve in front of the tip, and I can see a crack. Now, my left hand goes to the left and my right hand to the right, and I have a chop. We’ll show it again. Now I’m in front of the tip, and tipping it down. And I get a crack, and I separate the two. We separate… One more time. We separate. Now, the first piece generally should be the loosest, maybe the smallest piece. It’s almost like a carton full of soap cakes. The first piece is more difficult to take out. So like I just discussed, instead of going like this, I’m going at an angle. So that I am able to get a much bigger surface area to hold. I generated vacuum, and now I can pull it towards the center, and now I can eat the piece. This is on pulse setting. So one more piece. And I can eat it on pulse setting. Now, I can demonstrate the burst mode now. Can you change the settings to burst mode? Burst mode, as I press down, my off times get less, and so it’s a little faster, and it’s surgeon-controlled. So I can eat it faster. Can you increase the power a little? Increase. Yeah. So this is — I’m not pressing completely. As I press more, I can get more linear. Can you put some water on it for me? I’m now on my last piece. And so I should not — I should be slower. So I am… I don’t want things to go too fast. Because I don’t want any surge at this point. So with my foot pedal, I’m controlling it to be slower — I want things to go slowly in. I don’t want a lot of vacuum. Okay. So I have all the nucleus out. So I’ll be using a bimanual I and E. Now, to accommodate the bimanual I and E, I need to enlarge my side port. So if we have to do that, it’s better to do it at this stage, instead of trying to make large side ports right in the beginning. Because that would cause problems with the fluidics, during phacoemulsification. So here we have the irrigation, which has two irrigation ports, and this is the aspiration, which has one aspiration port. As long as the aspiration port is facing up, we are safe. And it shouldn’t tilt too much towards the posterior capsule. So I go inside the capsule, and I’m not pressing the foot pedal completely. And I’m trying to bunch up the cortex. When I feel there’s some cortex in it, by pressing the foot pedal, I come out, and I’m outside the bag, and here it’s safe to press my foot pedal completely. So the advantage with bimanual is that you can access the cortex from a safe angulation, by interchanging hands. One mistake I’ve seen a lot of young surgeons doing is that they keep the irrigation port very close to the wound, and it sometimes slips out. And so one has to be careful with what’s happening to the irrigation side as well, and not just focus on the… Okay. So we’ll be now ready to implant the lens. So you put some viscoelastic inside the bag. And we’re using an AcrySof UltraSert, which is a preloaded device. And we put viscoelastic through this hole. And we move this, and we just move the other lock. Now I move the lens. The interesting thing that this device has is that it’s got kind of a lock here. And so it doesn’t go further inside the wound. Because sometimes the tendency is if you take it way too inside, there’s no space left for the lens to unfold. So this is a guard that is there. We take it inside the wound. And it snugly fits there, and we inject into the bag. As you know, hydrophobic lenses unfold slowly, and that gives us a lot of time to… All right. And we now replace the viscoelastic with BSS. It’s important to remove almost all the BSS. Especially if you’re using a dispersive viscoelastic. It can tend to stick to the lens material. And so be patient to remove it. A cohesive viscoelastic, of course, comes out as a bulk. The DuoVisc helps and has both these properties. And now it’s important to make sure that our wound is well sealed, it’s watertight, we hydrate the incision, and… Get it nice and taut. All right. So this is how we use different steps in the machine. And as we prepare for the next case, I’ll be happy to take some questions. Okay. So we have a question from Dr. Radhof Pritam. Can you elaborate about using longitudinal power, torsional, and intelligent phaco, regarding when to use each one of them precisely? So longitudinal power is what you use conventionally in most machines. The torsional power is available only in a few machines, like the Infiniti or the Centurion. And I think some of the other companies have something similar to that. The torsional power is very interesting, because as we discussed, longitudinal power basically goes back and forth. The tip goes back and forth in a longitudinal fashion. But it’s a repelling force. So there is chatter, because of that. You want the piece to be cut, and then sucked in. But the longitudinal power has a tendency to throw it away. Now, torsional allows better follow ability. So the pieces come to the tip much better. And so you can get away with even lower vacuum settings. You don’t need very high vacuum settings, and that makes the surgery much safer. Also, it generates less heat, and so the next day your cases are much cleaner. The problem with the torsional is that you can imagine that it’s drilling a hole, and sometimes the piece gets stuck like that. And so to dislodge it, you either need your second instrument to dislodge it, so that a better position is presented, and so you need a burst of longitudinal phaco to unhook it from there. And that is what is called IP. If I’m not mistaken, when it reaches 80% of occlusion, a burst of longitudinal phaco comes in to dislodge it. So when we are chopping, we are in only torsional. Because we don’t want it to get dislodged. But when we are eating a quadrant, we turn the IP on, and that’s why in a Centurion, or an Infiniti, you have a separate setting for chopping, and then another setting for quadrant removal. Quadrant removal doesn’t require too high a vacuum. While chopping requires — so one can have slightly lower vacuum settings while you’re emulsifying the piece with IP, while when you’re just chopping, you can be 100% torsional. So that’s the difference between the two. I hope I’ve been able to elaborate. Then we have Dr. Kamini Prajapithi, who is saying: What are the settings in cases of iris coloboma, high myopia, and previous vitreoretinal surgery? Yeah. Now, the problem with high myopia, vitreoretinal surgery, and all these surgeries is that as soon as you take the probe in, your chamber becomes very deep. And the whole dynamics of the eye changes. Sometimes the pupil is very widely dilated. And then it tends to suddenly come down. There is almost like a reverse pupillary block that happens. And sometimes if you put an instrument behind the iris, you break it. In these settings, it’s good to have slightly low bottle height, and you slow down the machine, and like we discussed, having a torsional phaco helps, because you can work with lower settings in these machines. Also, if you can get away by not coming too much in and out of the eye, it helps. Coloboma of course is a very difficult case, because the zonules are weak. Sometimes your visibility is poor. And very often the lens is quite hard. All these cases one must ensure that at the end of the surgery, even if you feel your wound is competent, you should put a stitch, because there’s very low scleral rigidity, and the tunnel may not be very competent. We have Dr. Gupta. Which site do you generally prefer? Superior or temporal? So I tend to do it based on keratometry, largely. So the site which has the steep keratometry — that’s where I would put my incision. To relax that area. So if I have, say, 44 diopters at 90 degrees, and 42 diopters at 180 degrees, I would do a superior incision. A lot of our patients would have against the rule astigmatism, which is steeper at 180 and flatter at 90. Most all patients would have something like that. There I would do a temporal. If I have a bleb, then of course I would choose a site which is away from the bleb. If it’s a very deep-set eye, again, a temporal incision would be preferable. So I tend to generally, for most of my patients, I would be looking at the keratometry, and then deciding where I would place the incision, so that I can make it more astigmatically neutral. Okay. So we have another question. What should be the bottle height for different steps of phaco, constant or variable? Well, today with most of the machines, the fluidics are so well managed that you do not have much surge. You have disposable cassettes and tubings. The sensors in the machines, the venting that happens with all the tips, you do not actually have too much of a collapse. If you’re having collapse of chamber, then another thing which you need to see — is the height of your machine okay? Your pump where it rotates should be at the height of the patient’s eye, or a little higher. Not lower. If it is lower, then you may have collapse of chambers. Also in general you would keep the bottle height quite high. But if you have a motorized machine, like you have an Infiniti or a Centurion, then when you’re sculpting, it’s at moderate bottle height. When it’s in quadrant removal, the bottle height goes higher, because you’re using higher vacuum settings. In irrigation/aspiration, the bottle is kept high. But if you have to do polishing at low vacuum setting, the bottle comes down. So the machine can be preset to do that. But if you have a non-motorized IV pole, in general it’s good to keep it higher, as opposed to keeping it lower. Except for some of these cases, like high myopes or postvitreoretinal surgery. Another question: What is the reason to make the main wound before rhexis? What should be the ideal way to make it with side port first rhexis, main wound, or both? Well, I think it’s your choice. I was trained in an era where we learned extracapsular sutured cataract surgery, and then moved to phaco. And most of us learned — in fact, initially I used to make my rhexis through the main incision, and shifted later to making the incision — the rhexis through the side port. But I think today most people are doing a lot of manual small incision surgery in India, and they tend to use the side port for everything, for rhexis. I like to use the main incision, because I keep my side ports pretty small, and it’s difficult to put methylcellulose through a very small port cannula. So I like to do it through the main incision. However, it’s okay to use your side port for that, and because the side port that you use for rhexis actually doesn’t… Is not used during surgery, it’s the non-dominant — for a right-handed surgeon, you use the left hand to hold your second instrument — and that should not be very large, because that is what is going to leak, because you have an instrument inside. The side port that you use for your rhexis doesn’t leak during surgery, and so it doesn’t harm the fluidics during phacoemulsification. So it’s entirely your choice. A lot of people I know today tend to use the side port for both viscoelastic and rhexis. So it’s okay to do that. Dr. Al Kapandi is saying: What type of cartridge was that? That’s the UltraSert, which is a preloaded AcrySof platform. And that’s the cartridge we used for this case. So it’s a very nice preloaded lens. Which goes very smoothly. And as you saw, there’s no explosion in which the lens comes out. It’s very well controlled. Dr. Chandra. Why have you used longitudinal in Infiniti? Okay. So this was only so the case would be better for demonstration. We wanted to show longitudinal phaco, the conventional phaco, since this was a basic course, and we imagined that most people who are tuned in today have machines in which they do longitudinal phaco. So the machine is capable of doing both torsional and longitudinal. For this case, we preferred showing it through a longitudinal. That was the reason. Just for the sake of demonstration. Dr. Edisu. Can you please explain about the relationship of foot pedal movement while chopping to build vacuum during nucleotomy? Sure. So when we want to do chopping, we first need to hold the piece. Now, to hold the piece, we need to generate vacuum. To generate vacuum, we need to first go inside the piece. Now, you will be able… Because the tip has a bevel. And you have to get the entire tip inside the nucleus, and you’ll be able to do that only by first a little burst of phaco. So you first go in step three of the phaco. Depending on the hardness of the nucleus, you would need to use more energy or less energy. If it’s a soft cataract, you have to use very little energy. Otherwise you go through and through. But if it’s a hardish cataract — and also try to do it towards the middle of the piece or below. Don’t be too superficial. So you hold the piece where there’s meat in the piece. With a little burst of phaco, you go in step three, and as soon as you’ve gone in, you come to step two. And then you stay in step two. Don’t allow it to come to step one or step three. When you’re in step three, you break occlusion. You’re in step one, you break occlusion. So go in step three, then come to step two, stay in step two, to hold the piece, allow rise time to build vacuum fully, then chop. So it’s step three, then step two, stay in step two, continue staying in step two, while your left hand goes down, and you separate. All this while, the foot pedal stays in step two, okay? Next Dr. Tung. Can you share the height of bottle of different steps? I think we just discussed that. We’ll just send out what we used in this case. Okay. That’s probably the phone. Pixel 2. And not the name. How to remove visco under the IOL? What should be the setting? So depending on what kind of viscoelastic you use, if you’re using a very cohesive viscoelastic, like a Provisc or a Healon, then that is very important to remove from under the IOL, and sometimes if you have a bimanual, you can take the irrigation side of it slightly at the edge of the IOL, and go under and remove it. If you’re using a dispersive viscoelastic, all you have to do is stay in the eye long enough, and the fluid will replace it. It takes a little patience. If you’re using methylcellulose or something like a Viscoat, then you have to stay inside the eye quite long. Almost about a minute. To get all that viscoelastic out. You really don’t need to go below the IOL. Even if you stay in the anterior chamber and just nudge the IOL here and there, a little bit, most of it will come out and get replaced by the BSS. Dr. Yusuf. Would you prefer to reduce the bottle height for topical cases, assuming that the incisions are near perfect and not leaking? Not really. What is important in topical is that you don’t have sudden stretches. So whenever you go inside the eye, before you take the probe in, fill the eye with viscoelastic. So that there’s no sudden deepening of the chamber. So every time, whether you’re going in for I/A, you’re going in for sculpting, or you’re introducing anything inside the eye, whenever you’re doing that, you always put viscoelastic in a controlled fashion, slowly, so that it doesn’t cause a sudden jerk. That sudden stretch is what causes pain. It is not the continuous flow that causes pain. So I don’t change my settings of my bottle height or anything when I’m doing topical or I’m under block. I am very conscious of not getting sudden changes in the anterior chamber depth. Dr. Redding. The modified UltraSert injector tip is too lengthy for the IOL to unfold inside comfortably, compared to the previous smaller tip. How to overcome this? So I think it depends on what kind of incision you have, and so that much can go in. It has a guard, which actually keeps the tip only within the wound, and at best a little more. I don’t think it’s too long. And you’re right. You shouldn’t take the tip injector too much inside. Otherwise it won’t get space to unfold the IOLs. But I generally am fine with the current UltraSert. So how to prevent wound burns? Good question. One, if you have a hard cataract, instead of doing a clear corneal incision, be a little limbal. The sclera is a little more resistant — or the limbus — than the cornea. Number two, if you have a hard cataract, it may be good to come out of the eye in between. Put some viscoelastic. Allow it to cool down. And then go. And so a couple of times you come out, coat the endothelium with viscoelastic, allow the tip to cool off, and then go in. Number three would be that your wound should not be too tight. It should be adequate. So these are some of the tips I would like to give. Use adequate power. Not excessive power. Give breaks in between. And move your incision a little more posterior, instead of a clear corneal incision. What should be the width of the trench, and how deep? The width of the trench should be adequate to allow the tip to go below. So if it’s too tight, your sleeves will get obstructed, and will not allow the tip to go. So if it’s a hardish cataract, you sometimes have to widen the trench, because it’s a big nucleus, and you’ll need to trench deep. The next question is: How to judge adequate depth during chopping? During chopping. Okay. If it’s a hard cataract, we sometimes — and we’ll be discussing that — we do multipoint chopping. So it’s in situ. You keep holding. And since you asked this question, we can discuss it right now. You hold it with the probe, and you’ll take your chopper or a dialer down towards the optic nerve, and you find you reach only half thick. Now, at the same point, go deeper with the second instrument, and then go further and separate. And then if it has not gone right to the bottom, again at the same place you go further down and separate. So you keep going down. Instead of trying to do an excursion, which is a lot of movement, and that would cause stress on the zonules, you will stay with the probe, holding the piece, and with your second instrument, first you get halfway. Then you go further from that point to a little further down, and then a little further down. And only then you start excursing. That way, even in the hardest cataract, you’ll be able to get a chop. In slightly harder cataracts, what we do is that we need to do some preparation. One, never judge a cataract based on what you feel under the microscope. It has to be done in the outpatient clinic with a slit lamp. The red reflex that comes from a microscope can be very deceptive. Sometimes you can have a brown-black cataract, which might be giving a very good red reflex, and you’ll get into trouble if you’re not prepared for it. So always grade your cataracts. There is a LOCS classification, but you can create your own, so that you know what your 2+ means and what your 3+ means and what your 4+ means. It’s very important to do that. It should be well dilated. See whether your machine is capable of handling a hard cataract. Because some machines will generate a lot of heat and will cause too much of endothelial damage. So there shouldn’t be an ego that should come in your way. Do what is right for the patient. Having the right viscoelastics is important. You should have both a cohesive and a dispersive viscoelastic, if you can. Otherwise, methylcellulose, which is commonly available to most surgeons, is a pretty good dispersive viscoelastic. And that coats the endothelium quite well. And in between the case, one should come out and coat the endothelium, instead of trying to complete the case in one go. We just discussed how to do chopping. That we will demonstrate how, by staying in one place, you can go to different levels and get a chop. It’s important to know that sometimes the zonules are weak in hard cataracts, and so your hydrodissection should not be a big wave in one go, but in small quantities, in multiple places, and in case you’re not getting it in the first go, trench, reduce the bulk, and then go back and do some more hydrodissection. In a very hard cataract, what I like to do is I create a crater in the center, I debulk the nucleus, get some space in the bag, so I keep moving the lens and create a crater, and then through the crater, I may trench, and then go and do my stop and chop.
DR JAVID: So I’m gonna briefly discuss about the next patient that we are taking out. She’s a 55-year-old female from Delhi. Her unaided visual acuity in the right eye is finger counting, 2 meters, and 6/60 in the left eye. She has an NS3 cataract in the right eye, with a dense posterior subcapsular cataract and a cortical component as well. Her axial length in the right eye is 22.62 millimeters. Her keratometry readings are 46.01 at 135 and 46.22 at 45 degrees. We’ve chosen +21 diopter lens for her, and we plan to make her emmetropic.
DR MATHUR: We’re putting some Trypan blue in. Mainly so that it’s a little better visible. Although I had enough red reflex to do the capsulorrhexis. So I won’t say by Indian standards that this would be a very hard cataract. We’re doing our capsulorrhexis, again. Like I mentioned in the last case, it’s good to go spiral around where you started. And close out beyond where we started. So the capsule — lift the capsule up, and then we’ve got our blade. Bulk it out. Do one more. You can see adequate movement. You can try some delineation. Now, hydrodelineation sometimes may not be visible in all cases. It depends on the kind of grade the cataract is. So as we were discussing, before you take the probe in, it’s good to deepen the chambers. Because sudden change, fluctuation in anterior chamber, causes pain. Now, before you go in, always inspect the tip. Now, here, as you see, the tip is a little more exposed than what I would like. And the irrigating port is not on the side. And so it’s important to adjust that. So we go inside the eye. Currently in… So there are various ways of doing it. Some people will go and do a direct chop. But it’s always good to get a little space first, and doing a stop and chop is a good technique. And a very safe technique. So we will first trench. And as we discussed, because this is — the hydrodissection was very effective, it seems like a very mobile nucleus. And you can see if there’s a lot of movement, trenching becomes a little difficult. Because it’s just moving a lot. Okay. So we’ve got a trench, and I don’t know whether it was visible there. The posterior plate of this cataract was much denser than the superficial side. So we will separate. We go right to the base. And separate. And the posterior fibers require a little more power. So now we will be in the chopping mode. Where… Can somebody — what are the settings? We are at 380 vacuum. 34 flow rate. 85 torsional. And bottle height is at 95. And so now, if you’re over here, very superficial, you will not get an occlusion, because there will be a gap here. So you need to go further down, closer to the optic nerve, to hold. A little burst of phaco. Now I’m in step two only. I’m not in step three. I’m holding, and I press down, and I get a little crack. We have not got all the way. I keep holding into the crack. At another level. I’m still not completely cracked. And I separate now with the third crack. So this is the in situ cracking. At multiple levels. So you hold it well. Dip down. You get halfway. We’ve got a chop. Further down. And then you separate. Also, you may be tempted to eat the piece at this point, but in a hard cataract, you have very little epinuclear cushion. And so it is better to cleave all the pieces, because you’re using high vacuum and chopping. And so if there is no support, the posterior capsule can also get sunk. So it is better to chop all the pieces first, and only then start eating. So you hold again. Dip down. We get half a crack. Then you go further in the crack. And separate. Still not sure whether I got it completely. And so I want to be sure every fiber has a crack. And you can see I’m not excursing too much. By staying pretty much there, just with my chopper, I’m going down further from the crack, where I started the crack. So again, I dip down, and I separate, and separate again. Here I go. Now I’ve got all the cracks. Now I will be going to the quadrant removal setting, which is not too different from the chopping setting, except that now it has IP on, which is intelligent phaco. And I hold. A little phaco. Hold step two. Bring it to the center. Now I’m safe to eat. Now, as you notice, it keeps drilling. Now, when it is at almost full occlusion, it gives a burst of longitudinal, and that positions the piece at a much better location. So it gives a burst of longitudinal. So the piece… And as you notice, the probe remains quiet in the center. I don’t have to go searching for the piece, except when I want to get it out of the bag. And like I discussed, the best place with the 45-degree tip to get occlusion is at an angle. Not like this. Because this way I’ll have to use a lot of phaco to enter the piece. When I go like this, I get more surface area. And I don’t need to penetrate too much. The piece keeps coming, with the help of IP. The epinucleus. So always the second instrument comes out first. And only then the probe comes out. A small tip at this point. I sometimes go with my hydrodissection and loosen up the cortex. All the adhesions to the posterior capsule. Not only it works like a polisher, but makes the I/A easy. So all the places where the cortex is attached, by the time the probe gets ready, I sometimes do that. So I’m using a CoagSeal probe in this one. So hold the anterior lip, press halfway. Once it’s bunched up all together, then I come out of the bag and press completely and pull towards the center. So with the CoagSeal, when you’re inside the rhexis, you hold it. As soon as you’re out, you twist the probe, so that the aspiration port faces up. Lens, please. So that’s the DuoVisc. We’ll just make a little… Visco, please. And we’ll invert the locks. And then… Okay. Good. So Dr. Sritha Goli is asking: If inadequate cracking is done, how should we continue? Can we continue further or not? So I think it’s important to understand that you don’t have to start with chopping and cracking in the first. Divide and conquer is a very, very good technique. Very safe. And only once one has got four pieces, clean pieces, is when one should proceed further. Now, the main reason why one doesn’t get a crack is because you’re not deep enough in the center. And so I don’t know… In the beginning, you’re scared that you’re gonna go through and through, but that hardly ever happens. It’s more often that one is not deep enough, and I would say that no, you should proceed to doing the case. If you’re not sure of your crack, spend some time, and then go deeper, and crack it before you take on the next step. Because if you feel that you’re gonna be able to chop that piece, and it’s very hard, one can get into trouble. So I feel that one should first get two pieces, at least, if not four. And only then proceed further. Dr. Niha: What are the settings for pedal movement, phaco tip position, for epinucleus removal? So can somebody help me with the epinucleus settings? What we had today? So epinucleus, the power was very low. How much? Yeah, but it could be lower. 40, 50 linear. You have a vacuum of 330, 300, or something, and aspiration flow rate, again, is much lower. Something like 28 or 30. So you basically bring it down. You don’t want that very high vacuum. You can actually keep even 200 vacuum. Slightly lower flow rates. And very little phaco. For epinucleus. Maybe 30% should be adequate, depending on what kind of nucleus is left. Henry: I saw two bottles of BSS hanging. Is it the phaco machine that determines the flow rate, or it is done manually? No, we actually had only one BSS hanging. With the phaco machine. Your question… Is it the phaco machine that determines the flow rate? Or is it done… No. So the flow rate you set initially. It is generally what you fix it. It’s not much that you’re modulating during the surgery. So when you’re sculpting, you keep it at low flow rate. Something like 20CC per minute. And when you’re emulsifying a piece, somewhere between 32, 35CC per minute. And that is what you’ll get during surgery. You can’t really modify it much, while you’re operating. And the next question is: Is that much manipulation hydro need for the cataract? Is it necessary to movement of blade during the incision? Good question. Good observation. With the hydro, there are different ways of doing it. One hydro is that you stay in one place, lift the capsule up, inject with the jet, and you should get a wave. Now, that’s ideal if you can get it. In my first case, I actually didn’t get a very good hydro wave. My cannula — I didn’t get a very good wave. And so I sometimes go from one quadrant to the other, and while I’m doing that, it also cleaves some of the corticocapsular adhesions, and that way I get much better hydrodissection. So normally it should be just one or two places, and you should be able to achieve, but it also depends on the kind of cataract you have. If you have a cortical cataract, sometimes getting a good hydro wave is not very easy. The blade should — if it’s a sharp blade, one can just go in and out, and it actually doesn’t require side movements. But you don’t want it into a very smooth trajectory inside, that you hit the anterior capsule. And also, you should not be pressing the posterior lip. You should have no leakage from the wound. So it should actually be a straight in and out, without any side movements. I would agree with the observation. How to do soft shell technique, cohesive-dispersive, or along with chondroitin sulfate or Viscoat? When to use it? How to wash the thick visco sandwich? So the soft shell technique basically — when you have a hard-ish cataract, or you want to protect the endothelium in a case with poor endothelial count, you need a dispersive viscoelastic to coat the endothelium. So something like a Viscoat. You put a layer close to the endothelium. However, you need to create space, and for that, you need a cohesive viscoelastic, which you put below. So the problem with the cohesive viscoelastic, if you were using only a cohesive viscoelastic, it’s very good for your capsulorrhexis, but as soon as the probe goes in, all of it comes out as a bulk. And so the endothelium is not coated with it. So in a soft shell, you coat the endothelium with the dispersive viscoelastic, and you have a cohesive viscoelastic below. That helps in protecting the endothelium, as well as the cohesive part of the viscoelastic gets space and makes the capsulorrhexis easier. Helps in getting more space inside the eye. So I would tend to use it in a hardish cataract. In case with guttate changes, I would use both a cohesive and a dispersive viscoelastic. How to wash it out? Well, the cohesive part comes out as a bulk. With the dispersive, you have to stay inside the eye much longer with the irrigation and aspiration. And over a period of time, the BSS replaces the dispersive viscoelastic. If it is stuck behind the lens, if you’re using a bimanual, you can take the irrigation behind the IOL. That pushes the viscoelastic out. You can do that. Or just tilting the lens to one side, with a second instrument, will allow most of the viscoelastic to come out. Dr. Janani: What is your opinion about sub-Tenon’s block? Is that better than peribulbar? The peribulbar is a little one-time pain. The sub-Tenon’s one is good for the people who are now wanting to move from peribulbar to topical, but are not totally confident. So you will achieve anesthesia, but not so much of akinesia. It can give you practice of operating in an eye which is moving a little. But otherwise, sub-Tenon’s causes sometimes a lot of subconjunctival hemorrhage, which the patients don’t like. What I’ve noticed with topical is that it pretty much takes care of the pain. You often have very anxious patients. They are the ones who move a lot. But otherwise, a topical takes care of the anesthesia. Younger patients sometimes have more difficulty. You have more difficulty with younger patients. Probably they have more pain sensitivity than the older patients. If you’re able to give some sedation, like a midazolam, along with the topical, generally that helps quite a bit. So I’m not too enamored by sub-Tenon’s. I prefer topical, if at all, with some sedation. Dr. Nicunj. Difference between a beginner and expert phaco surgeon, while doing hard cataracts, is visible on first postoperative day. DM folds, corneal edema, wound burns. Tips to improve on that? One is that you remain a little more posterior. I think when you’re a little edgy, you’re not that confident, you tend to bring the pieces in anterior chamber much more and eating it there. So you tend to stay in the bag a little more when you’re a little more confident. Two, you in between should use some viscoelastic. Come out. Coat the endothelium with dispersive viscoelastic, and like I said earlier, even methylcellulose is actually a pretty good dispersive viscoelastic. So nothing wrong with using methylcellulose. Do it a couple of times. So once you’ve cracked the pieces, then go with viscoelastic, and only then start eating. When you’ve eaten half the pieces, then again come out and put viscoelastic. Also, the machines make a difference. I think if you’re using torsional, it probably generates less heat, and also the pieces are not flying here and there, which may cause some endothelial damage. So if you’re using a torsional phaco, your corneas are much cleaner than otherwise. About the wound burn, in a hard cataract, I prefer using slightly posterior incisions, and not clear corneal incisions. And that can help in reducing wound burns. So I think it’s more to do with chamber dynamics, not allowing shallowing of chamber, trying to be a little more posterior. Also I like to — like you noticed in my last case — I like to chop all my pieces, and only then start eating. And chopping them not in four quadrants. I’ll chop them in sometimes 6 to 8 or sometimes even 10 small pieces, so that the pieces are not very big when you bring them in the anterior chamber to eat. Next question. What is the best way to manage the last piece to prevent PCR? That’s an important point. So we discussed most of the time the PCR occurs because of shallowing of anterior chamber. One: Be inside the eye. In the beginning, especially in India, since most of us — and otherwise, also, we go through Simcoe and SICS, or extracapsular surgery with Simcoe — in Simcoe, as soon as you hold the capsule, you have a tendency to come out of the eye. That reflex is sometimes there with you for a long time, even with the phaco surgery. In phaco, the safest place is not near the wound. The safest place is in the center of the eye. So stay in the center of the eye, and not towards the wound. If you come towards the wound, your irrigating ports are either in the tunnel, which hydrates the wound and makes it all hazy near the wound, or you’re outside the wound, and your chamber will collapse when you’re holding the piece, because there’s no irrigation inside. Chamber collapse will cause the PC rent. So be very careful that you’re inside the eye completely, with your irrigating ports inside the eye, and not in the wound. Lower your settings. So sometimes if it’s not a very hard piece left, you can go to epinucleus settings, so that as we discussed earlier, lower flow rates, lower vacuum settings reduce the chance of surge. And by doing that, you will prevent, again, chamber collapse. Also, your tip — your piece — don’t go under the piece, when you’re eating. You should be partially visible, when you’re eating the piece. And eat it in small pieces. Sometimes it’s good to go in step three, step two. Step three, step two. You go slowly, slowly. You don’t want a lot of pieces going in together. You make it into smaller pieces, and then only you take it in. And that way, your last piece is the time when you have most PC rents, and you can even put some viscoelastic in, before eating the last piece, so that it gives a little cushion. And some of it will stay, if it’s a dispersive viscoelastic, when you’re eating that piece. So our friend, Dr. Weber… Okay, so he’s… How do you manage a broken haptic? So if it’s a broken haptic, sometimes the trailing haptics get stuck in the butterfly injectors of some of the injectors that we have. And it can be a big bummer. You’re really cheesed off. Because you think your case is almost done, and at that time the haptic gets broken. So if it’s a broken haptic, and if it’s just a little edge of it, sometimes you find that your lens is quite stable and you can leave it there. But if a lot of that haptic is broken, one would need to take it out. Now, you can… If you want to preserve your size of the incision, you first have to get the lens out of the bag, and by dialing it out, then put a lot of viscoelastic, and with Vannas scissors, you can actually go and cut it into half. You don’t have to… Somewhere in the middle of the lens. And then by turning one half of it out of the incision, and then the other one follows out… That’s one way of doing it. But if you’re in trouble, and you’re not too confident, I would suggest you extend the incision to about 5 millimeters, grasp it, take it out of the bag, grasp it with McPherson’s forceps, and just yank it out and replace it with another lens. I don’t think one should bother about the astigmatism at that time. I think it’s more important that you don’t rupture the posterior capsule in trying to do a lot of maneuvers. So there are a lot of videos available on how to get a lens out by cutting it halfway and then turning it and taking it out through the same incision. So you could look at that. Okay. The next question: In Infiniti or Centurion, do you recommend bevel up, during emulsification and chopping? I do it. If you have to hold the piece — the Infiniti and Centurion, because it’s OZil, they are more effective with a 45-degree tip, and not as much with the 30-degree tip. They’re pretty inefficient in cutting with 30 degrees. So most of the time you’ll be using a 45-degree tip. And so if you normally have a tendency to do everything at 6:00, you have to do a lot of excursion into the nucleus to hold the nucleus. And if it’s not a very hard cataract, you don’t have any purchase to hold. So like I was trying to show you, you actually put the piece a little between 4:00 and 5:00, and turn your bevel on the side to get a good hold. So instead of doing it with bevel up, I like to do it sideways. I get a large surface area to hold the piece, and I don’t need to penetrate all the way into the nucleus. Okay. Dr. Ashish. If the IOL on opening in the bag turns upside down, what should be done? Not much. Actually, most of the lenses today — unless you’re dealing with a toric — don’t do badly if they’re upside down. They’re mostly biconvex. Maybe a very small change in refractive error. But the only thing you have to do is dial it the opposite way. But the other way is — if you’re not completely in the bag, especially if you have a lens like an AcrySof, you can actually do quite a lot of acrobatics with it inside the anterior chamber. You can flip it. With two instruments. You can actually flip it inside the eye. And it works quite well. Take it out of the bag. And you can actually flip the lens with two instruments. But if you don’t want to do a lot of heroics, even if you leave it in the bag, upside down, it won’t do too much harm. Our next question: Which biometry formula do you use? Reason for the same. Thanks. Well, very good question. The fact that we have so many formulae suggests that they’re not perfect. Now, between, say, something like an 18 to 24 diopters of IOL power, I think most formulae are fine. For myopes, we tend to use SRKT, and that has been giving us pretty good results. For most of our normal range, as well as the myopic range, we tend to use SRKT. For the hyperopes, we tend to use Hoffer Q. When we are dealing with a post-LASIK or post-refractive surgery patient, Hages works quite well. So depending on what kind of a case we are dealing with, we tend to use that. If you’re seeing a lot of range in different formulae, tend to make your patient myopic than hyperopic. Most patients are happier being myopic than hyperopic. So if you have to err, supposing one formula is saying 19 and the other is saying 20, I would tend to put 20. Okay. Our next question, Ijasun: Which is better for capsulorrhexis? Cystotome, bent needle, or capsulorrhexis forceps? Is there any superiority of one technique? Not really. There’s no difference in the final outcome. You can make it the way you have practiced and the way you have learned it. In India, because of cost economics, we tend to use methylcellulose, and we don’t have the luxury of using a very cohesive viscoelastic, like a Healon or a Provisc, most of the times. Now, when you’re using a methylcellulose, when you use capsulorrhexis forceps, it tends to run out through the main incision. And so in general, most of us have got trained with using a bent needle. And in our hands, that works well. But I think it’s good to know both the techniques. The capsulorrhexis forceps really helps when you have zonular dialysis. Then the rhexis forceps help. Or if you have a running-out rhexis, then you can hold it much better and bring it back in with the forceps. So there’s no difference in the quality of rhexis. Whichever way you do. I think most of us are more confident with a certain method, and we tend to practice that. You could continue using your technique, and I think there’s no difference in the way… Whether you make it with a forceps or otherwise. Dr. Raga. Phaco tip tends to block while operating on hard cataracts. Can you explain why this might be happening on Infiniti? Yes. So as we discussed, you have a small little thing in the middle of your screen. If you look at your Infiniti machine. Which says IP. Now, when Infiniti was launched, with torsional phaco, one of the big problems that they were facing was that all the surgeons were complaining of the pieces getting stuck in the tip. And they had to come out and flush it. And that was a big pain. And so they decided bringing a burst of longitudinal phaco, just when the occlusion was happening — at about 80% occlusion, if I’m not mistaken. And that dislodges the piece. So you should have two settings. One for chopping and one for quadrant removal. In quadrant removal, you should have IP on. And that IP on dislodges the piece, and doesn’t block the tip and the tubings. That helps. The other reason why you may be having a lot of blocking is that you’re not using adequate power. So you need to use — and some of the smaller pieces may be getting stuck in the system. So you use adequate power. Use IP and quadrant removal. While in chopping, you can keep it off, because at that time, you don’t want a break of occlusion. So the longitudinal burst that you get with IP is very useful in preventing this phenomenon. Okay. Next question. I appreciate your introduction about phaco tips, the bevel, and exposure length. How about your experience if you use phaco tip and level down? I’ve heard a few people talk about it. I’ve somehow never used it bevel down. I think bevel down can be used if you’re going for direct chop, and you may get a good seal that way. I tend to do stop and chop, where I want to make a groove. I tend to make a groove. Make a trench. And I would think that you would be able to cut much better with a bevel up, and not a bevel down. But I think if you’re wanting to hold, you could hold it bevel down. But I’m sorry. I don’t have experience with the bevel down phaco. Dr. Belrad. What are direct chop, stop and chop, divide and conquer? A little confusing. All right. So the conventional phaco — the way it started was that we make a trench. First a longitudinal trench. From 12:00 to 6:00. Then you rotate the nucleus. And then you make another trench, crossing it. Right? You may need to rotate it 180 degrees and 90-90 degrees, so that you keep attacking one quadrant. And you get four trenches, like a cross. That is the conventional divide and conquer. You divide into four quadrants, and then you conquer each one of them by eating them. The next technique that got evolved was stop and chop. So it was: You make a trench from 12:00 to 6:00. And then you stop. So that’s why it’s stop and chop. You don’t make the next trench, which is crossing. So it is a single trench. And you stop. And after you make the single trench, you crack it into two. And each of the halves that you have you will chop. That is why it’s called stop and chop. The other technique is direct chop. Where you don’t make any trench. You don’t have any sculpt settings. You go directly with the chopping step. And straight with the probe, you bury into the nucleus, hold it, and then you make the chop with your chopper. And you generally need a sharper chopper. What I was demonstrating was a vertical chop. Where you really don’t need a very sharp chopper. Peripheral chop has a cutting edge on the inner side of the chopper. And you go inside the rhexis, and you bring it from the periphery towards the center. You need a sharp chopper for that, which has the cutting edge on the inside. And you chop the piece. There is no trenching. You go directly, with direct chop, chopping the nucleus. So divide and conquer is four quadrant sculpting. And then separating. Stop and chop is: You just make a single trench, and you stop, and after that, you crack into two, and start chopping. And direct chop is you go directly into the nucleus with chopping. Okay. How to hold globe? Usually it goes the other way when phaco probe enters one end. I know what you’re saying. This happens very often with beginners. One of the things that I’ve seen is that when you’re an SIC surgeon, you use the superior rectus bridle suture very effectively in delivering the nucleus. Now, that superior rectus suture basically makes the eyeball go down. So even if you want to use it, so that in case you want to convert, just pass the needle, but don’t pull on it even once, because then the eyeball has a tendency to go down. Usually in a phaco, you don’t need it. But if in the beginning you want to use it, it’s fine. But don’t pull on it. The other reason why it goes down is that, instead of using enough power by pressing the foot pedal adequately, you’re using your muscular power to move the probe. So if you’re using adequate power, your nucleus, as well as your eyeball will not move. It will stay in situ, when you’re sculpting. But if you’re using a lot of force to move the probe, without using enough cutting power of the machine, then there will be more rocking movement. So please understand: Using inadequate power is not safe. If you’re using less power, you’re causing more stress on the zonules. Also use your second instrument effectively in pulling the eyeball straight. So don’t make a very large second side port. Use it for oar locking. As you will have noticed boatsmen — they tend to use their oars? It doesn’t move too much. It rotates around the same axis. Similarly, if you have a lot of play, and you have a very large side port, you will not effectively be able to control your eyeball. So make — not a very large side port, but just about enough to hold the second instrument in, and that way, you will be able to pull the eyeball straight. So the probe, even if it is pulling the eyeball down with the second instrument, you pull the eyeball straight. Okay? Dr. Pushka. What to do when some fibers remain, when trying to divide a leathery cataract? So when you have a leathery cataract, you have to use this technique which I showed you today, where you hold the piece with good vacuum, and because it’s a hard cataract, you have to bury the tip well enough, keep holding it there in step two, you dip down your chopper, separate, and you won’t be able to get it in one go. Now, the crack that you’ve got, from that crack, you go further down, and then separate a little more. And then you’ll be left with some fibers. You again keep holding it there. Go into the crack. From that point, and again, move towards the optic nerve. And then separate. Sometimes you may need to do it four or five times in the same place, to reach the bottom. So very leathery cataracts are tough. You will need to do that. Also remember: Most of these very brown cataracts have big zonules, so if you do a lot of excursion, you may have zonular dialysis. So it’s good to do it in situ. Not too much of excursion, but you keep going down. And you’ll do that. Dr. Mohan. During emulsification, is it safer to hold the tip of the bevel up or sideways? And if sideways, do we have to come out to change the sleeve orientation, to keep the irrigation opening sideways? To help the pieces to come towards the tip? Not really. You don’t really need to come out. If it’s going at an angle, it’s fine. The fluid — it doesn’t cause too much damage to the endothelium. So you hold the piece in the bag. Bevel sideways. Once you’ve brought the piece in the center, you can again twist your probe so that the bevel is up. So it’s only to hold that you need to do it sideways. Once you’re eating it, you can again be bevel-up. So let me just read through some of the pieces, because we have only about five minutes left. If there’s any repeat. So we have, during the last piece removal… Do you recommend placing the second instrument above or below the piece during emulsification? I don’t think it makes too much of a difference. You basically have to understand the fluidics and prevent surge and do it slowly. What changes should we make in settings in patients with small pupil and floppy iris? So one, with floppy iris, if you’re anticipating, be very careful of how you’ve crafted your incisions. You cannot be premature. You have to be very clear corneal. Side ports also have to be very clear corneal. And don’t make them large. So it’s very important to do that. Most of the time — and don’t overfill your eye with visco. Sometimes the tendency is that I want to make my chamber deeper. And because the eye itself — and in India, we get a lot of shallow chambers. Doesn’t have space. If you overfill the eye with visco, more iris will come out. So you should have just enough visco. Don’t overfill it. That is what causes most of the problems. Your tips on transition from divide and conquer to stop and chop? Well, divide into four quadrants, and then chop each of those quadrants. Even if you’re not able to chop, you’ll have four pieces, and you can finish the case. So first make four quadrants, and then divide them by chopping further. A few tips to do soft cataracts? Very good hydrodissection. And if in hydrodissection you find your cataract has come popping up out of the bag, that’s okay. Because you’re not going to use much machine energy. And just suck it out in step two. Otherwise, you make a very narrow trench, and a deep trench, and get into two cracks. Don’t try to do four quadrant in soft cataracts. Only two quadrants. And each of those halves you can again hydro, and allow them to pop up, and then suck them out. Stop and chop versus direct chop? Tips to do phaco in 5, 6 millimeter, without using expander… Well, if you have an OZil, which has very good follow ability, you can stay pretty much in the center, and get away without needing any of the expanders. So use low flow rates, low vacuum settings. Do in situ cracking, stain the center of the eye, and things will come to you. And you can actually get away with 5 to 6 millimeter pupil. Stop and chop versus direct chop? No particular reason, except stop and chop I think is an easier process, because you will create space in the bag, before you start chopping. So stop and chop, I feel, is a more universal technique. Direct chop sometimes can be a little tricky. Dr. Kantilal: Condition of PCR during quadrant chop… Does reducing AFR in settings reduce the flow of BSS? Because high flow… When you have a PC rent, actually the most important thing is not to lose chamber. So use a cohesive viscoelastic inside, and only then come out. Don’t allow things to come out. And yes, slowing down the machine, both vacuum and flow rates, will help. There will be less turbulence. Depending on at what position you get it, you’ll have to manage it. I think that’s a separate discussion altogether. It will be difficult to discuss over here. So yeah, soft cataracts. Next question: It’s difficult to do chopping. And I think the best way is to try and get two quadrants by doing a deep trench, and thereafter, you can just eat it. You don’t need to make four quadrants, and chopping is not the best idea. Dr. Jethi. Which tip have you used in this case? I think we used a Kelman tip. Kelman flared tip. It was a 45-degree tip. With the Infiniti OZil, 45 degree scores over 30 degree, because the cutting action of an OZil is not very good with a 30 degree. From direct chop… To stop and chop. One, it’s not necessary to shift. And if you need to shift, don’t use… Start with some of the easier cataracts. 2 or 3 grades instead of 4 grades, which don’t give you much space in the bag. And bury, and then do it. So choose the right patient, and then you can start doing that. Also, you may need to change your chopper. So you’ll need to see what kind of chopper you’re using currently. And for direct chop, what kind of chopper you need. Dr. Prithi: How do you deal with a small pupil? I think we’ve discussed this. Dr. Ankil: What are the preparations one should take while doing phaco in a hard, complicated cataract? With a thick, calcified… I think preparations are that you need to know what machine you’re using, whether that machine is capable of doing hard cataracts, you need to have the right viscoelastics available to protect the endothelium, and the right choppers, if it’s a very hard cataract. Phaco settings, again — you’ll need to use higher cutting, more power, slightly more aggressive settings, in a harder cataract. Are we out of time? I think unfortunately I won’t be able to take the other questions. I think our time’s running out. We have your email addresses. I think you can send in your queries. We’ll be happy to answer them through email. This was a fantastic, I think, way of reaching out to so many people in different parts of the world. I think I would really compliment Orbis for the Cybersight platform they’ve created. I really enjoyed the session today. I hope it was useful. And we’ll keep doing more of these. So thank you so much. Our team over here, our nurses, our fellows. Alcon, for all the support. And Orbis, for organizing this. Thank you very much.