Lecture: Managing Astigmatism at the Time of Cataract Surgery

In this moderated panel, five expert refractive cataract surgeons will discuss their journey to correct astigmatism in their cataract patients before phaco surgery. The webinar will cover five aspects of eye care: (1) management of patient expectations, (2) calculating measurements for Toric lens while overseeing and planning for posterior corneal astigmatism and femto-AK, respectively, (3) execution tips and tricks for Toric surgery techniques, (4) LALs, Toric IOL update, and bioptics, and lastly, (5) management of astigmatism in complex corneal situations. Questions received during the registration and webinar will also be discussed. (Level: All)

Moderator: Dr. Balamurali Ambati, Ophthalmologist, University of Oregon, USA

Dr. Vaishali Vasavada, Ophthalmologist, Raghudeep Eye Hospital, Jaipur and Ahmedabad, India
Dr. Jerry Hu, Ophthalmologist, Texas Eye and Laser Center, USA
Dr. Dagny Zhu, Ophthalmologist, NVISION Eye Centers, USA
Dr. John F. Doane, Ophthalmologist, Discover Vision Centers, Kansas University Medical Center, Department of Ophthalmology, USA


DR AMBATI: Hi. Good morning. My name is Bala Ambati. We’d like to welcome you to the Orbis Cybersight webinar: Managing astigmatism at the time of cataract surgery.

We have an excellent panel today. Dr. John Doane from Kansas City, Dr. Vaishali Vasavada, from Gujarat in India, Dagny Zhu, from NVision Eye Centers in East LA, in California, and my great friend Jerry Hu, from Texas Eye and Laser center in the Dallas Fort Worth area.

And I think what you’ll find today is that each of the speakers is presenting a different prism of perspective in terms of how to best approach astigmatism at the time of cataract surgery. Our real goal for today’s webinar is to demystify management of astigmatism.

Sometimes it can be a very formidable or difficult thing to manage with. And we’re going to attack the problem of astigmatism in terms of expectations, alignment, measurements, and how to deal with complex situations.

Our first speaker today is going to be Dr. Vasavada, from India. Her talk will be about the management of expectations. How to approach and properly discuss toric lenses, to avoid the unhappy patient.

In our field, we often think about 20/20. But really, we need to think about 20/happy. And how to achieve patient expectations is critical. So with that, I will mute myself. And then turn it over to Vaishali. Thank you very much.

DR VASAVADA: Thank you so much. Good morning. Good evening. Wherever you are on the planet. And thank you, Dr. Ambati, and to Cybersight, for having me in this very important webinar.

Now I’m able to share my screen. So today I really want to discuss what I find useful or what I think helps me in managing patient expectations, but also in really approaching the whole concept of astigmatism correction, and how we can have happy patients.

I must declare that I do receive a research support grant from Alcon Laboratories. So before we start off, I just wanted to understand from the audience perspective — and can we have the poll question online, please?

The question being: What is your threshold for correction of corneal astigmatism today in cataract surgery? You have four options. And let’s go for the next 20 seconds.

So yeah. It seems like most of us — 40% would go for toric IOLs when the astigmatism is more than 1.5 diopters. But a large majority, another almost 40% would treat anything above a 0.75 diopters. And there are about 20% of people who don’t use toric IOLs.

And I hope this webinar helps them to sort of move on, or to start with toric IOL implantation. Because really, they are a great tool in correcting corneal astigmatism.

Now, I want to start with this survey, which was conducted by the American Society of Cataract and Refractive Surgeons in 2018, and this is a little old data. It’s about five years old. But still, at that time, most ophthalmologists do agree that astigmatism needs to be addressed at the time of cataract surgery.

And yet, even in one of the most developed nations in the world, only about 22% of patients receive toric IOLs at that point of time. So then what are the key factors? Based on this, we must understand there’s a long way, wherever we are in the world, there’s a long way for us to go and correct astigmatism, particularly with toric IOLs.

In my mind, the three main factors are: One is to recognize the astigmatism, second is a very meticulous evaluation, and third is conveying these technologies, conveying the limitations of these, and what to expect, to the patient.

Which sometimes is one of the major challenges. So to understand this, how do you understand astigmatism, and therefore approach it with your patient? We did a study of over 2,000 patients undergoing cataract surgery in our center.

And we found that as you can see here, about 56% of them had at least half a diopter or more of corneal astigmatism. And this is something which is now correctable with toric lenses very well. And there are other publications which have shown similar data.

So that means at least five of your ten cataract patients need astigmatism correction in one way or another. The other question is: Does low astigmatism matter? When it is above 0.5, 0.75, or 1 diopter, a lot of the old theories do say that having some amount of against the rule astigmatism might in fact help your depth of field.

So we did a study where we randomized pseudophakic patients. These all had IOLs in their eyes, monofocal lenses. Not torics. And one group was where the astigmatism was 0.25 or 0.5 diopters. The other, it was either 0.75 or 1 diopter.

And we focused on the finer aspects of vision. Mainly the contrast sensitivity on the vector vision charts, and the reading speed. And what did we see? When we looked at the contrast sensitivity unaided, the group one — that means those who had 0.5 diopters or less of refractive astigmatism significantly had better contrast sensitivity, particularly in mesopic conditions, as opposed to those who had 0.75 or 1 diopter.

And even after astigmatic correction in the form of glasses, group 1 with the lower astigmatism performed significantly better than those that had 0.75 or 1 diopters in mesopic conditions, particularly when you look at high spatial frequencies.

So I think what we understood — and that has helped push us or conveyed this to patients more confidently, our body language, the way we train our staff, the way we talk to our patients has changed, because we understand that it really — this is a science that makes sense. To correct at the IOL plane. As compared to correcting at the spectacle plane.

Also, when we looked at the reading vision of these patients, there was the reading acuity and the reading speed, again, were much better when you had half a diopter or less of refractive astigmatism. So I think the first and foremost thing that we need to understand as surgeons, unless we are convinced about any technology, surgery or IOL or glasses, it doesn’t really penetrate or percolate that well to the patient.

So we need to understand that correcting even the smallest degree of corneal astigmatism is important. Now, the other aspect which we must understand, particularly when you’re beginning with toric lenses, is that what you measure on the cornea is only one part of the entire spectrum of astigmatism.

What we also need to factor in is what you induce, or what you are going to add, after your surgery. And therefore I think for most of us, if you’re starting out, at least once in your surgical lifetime, it is a good practice to calculate your own surgically induced astigmatism.

Have at least 40 or 50 cases with the same incision size and location. And I think we have very good online calculators now, which will do that for us. So that really helps us to understand how much we are going to add to this corneal astigmatism.

So let’s take this example. And I must acknowledge Dr. Warren Hill here, who actually taught me this, many, many years back. That if you have about 0.75 or 1 diopter of astigmatism, you are going to add anywhere between 0.1 to 0.3 diopters, depending on your incision size and location.

So again, if you add this, particularly when the astigmatism is horizontal, against the rule, you’re going to probably add to this, and therefore a lot more patients become candidates for toric IOL implantation.

So this is what I also wanted to encourage everyone to understand, their own induced astigmatism. And I understand that we are going to discuss the pathway of evaluation in posterior astigmatism. So I won’t go deeper into that.

Moving on, once you know that it’s good and makes sense to treat astigmatism, why would you opt for a toric lens and not an LRI or AK or glasses or contact lenses? So I think today this technology has matured to a level where it has become a component of a routine cataract.

You don’t have to do too much extra. So in terms of time or effort, it is not an extra procedure. It is just part of your normal cataract surgery. The most important thing is that the treatment is very predictable. It is very accurate.

And there is no regression. You don’t typically see regression over time. And if there is something wrong, if you put the wrong power or the wrong axis, you can always address that. So you are not in an irreversible situation, that you have made a cut and you cannot undo that.

So I think this is why I like to try and use toric IOLs more and more in my practice now. When you choose a toric IOL, if you want a happy patient, if you want consistently good results, it is also important to choose the material and the type of lens.

Whatever material, whatever brand you choose, that’s really up to your preference. But it should have a good rotational stability. It should have a good biocompatibility and adhesion. So that the anterior-posterior movement doesn’t change the spherical refraction. The ELP.

And it doesn’t induce much inflammation. The good part now is that across the world, we have several manufacturers who make really high quality toric lenses.

And this is a shot I took from one of the recently published articles, which tells us about: What is the average rotation with different commercially available lenses. And this might help you to choose or to understand what is happening to your IOL.

Now, I think the most important part in ensuring a happy patient is to make sure that you pay attention to every detail. Because even in the modern times, with all the good technology available to us, nothing beats a good scientific practice.

And here I want to make only a few points. To me, what I find very useful is: Have a dedicated protocol or a dedicated time when your entire staff, including the optometrist, the counselors, yourself, you are all available to deal with those preoperative patients. Often in a very basic clinic, you’re seeing 10 or 15 patients, and there’s this one patient who also wants a cataract surgery.

So as far as possible, if logistics allow, it is a good idea to have a separate time that is allotted, so the patient also realizes the importance of the work-up or the investigations that are going to be done. And you can always call in family or friends or the caregiver at this time.

So that they can also be active partners in the decision making. Always evaluate both eyes. I have experienced this myself. And therefore have learned the hard way. That sometimes you don’t have astigmatism in one eye. You do that eye, the patient is very happy.

Now, when he or she comes back for the second eye, you realize that — oh my God. There’s 1.5 diopter of astigmatism. I never discussed toric lenses with this patient. And in those situations, particularly when the patient might have to pay out of pocket expenses, this might become a tricky situation.

Or maybe one eye has a retinal pathology. So always do a complete preoperative evaluation of both eyes. Even if one eye is pseudophakic. Even if only one eye has a cataract. So this is something I tell my team to enforce very strictly.

Evaluating the ocular surface is a very often missed out aspect. And we may not do a Schirmer test for everybody, but doing a lid margin evaluation, look at the tear film, does it have all the debris or does it really have a lot of water — on the conjunctiva, conjunctival calluses. Because all these surface problems are going to lead to an unhappy patient, even though your toric IOL is doing its job very well.

How are dry eyes or ocular surface problems relevant to cataract or refractive surgeons? One thing that we sometimes don’t discuss is how it affects your biometry. So I want to show with this case example. Here on the left, you see: Topography, Placido topography, prior to lubricants. And you can see the distorted mires. And now you see following lubricant, it becomes regular. So with this irregular astigmatism, it goes to regular.

And you can see the abrasions on the cornea and the large red and blue bars have dropped significantly. This is an optical biometry from a patient. On the left you can see keratometry, 42 and 43. This patient was diagnosed to have an ocular surface problem. And after treating the surface, the keratometry has changed by almost 1 diopter, and even the spherical IOL — if you look at a monofocal lens power, the diopteric power has jumped by 1 diopter.

Even if you do a good toric calculation, put the lens well, brilliant surgery, but if your surface was not good, you could have a spherical error, which ultimately mars your outcome or the happiness. Anything you do, if you have a manual keratometer, it doesn’t matter. You don’t have to have an automated device all the time.

But please be very precise and very particular in doing this. I have taken this picture to show if you can notice — it’s difficult to see here. But there is a slight tilt in the head. So make sure your patient is comfortable, well aligned, even if you’re doing an immersion A scan, like I said, you don’t have to have the most modern technology.

A well performed visual fixation and a well performed examination will go a long way. Use the modern formulae. And here I want to put in a red flag of an irregular astigmatism.

There are times when we need to respect the technology, and we need to convey this to the patient. That your eye may have a limitation, or the technology has a limitation. And even if you want the toric IOL, your eye may not be suitable for this.

Signs that make sense. Depending on where you practice, the culture of the region where you live, involving key decision makers, or sometimes the children or the spouse or the caregivers, might also help the patient in choosing the right technology for them. Or in understanding what to expect after surgery.

And this is a picture I just took off online. And a lot of companies and industry has good simulators, which you can use to show them what happens, whether you correct the astigmatism or not.

A small point I want to make about aberrometry — here is a case of a 52-year-old man, who has 1.2 diopters of corneal astigmatism, and you would want to correct it. But when I talked about toric lenses, he said: I’ve never worn any astigmatic glasses. Why would you want to implant a toric lens in my eye?

Here is where technology became useful. This is taken from the aberrometer. The red bar is the internal astigmatism, typically coming from the crystalline lens. This is a phakic patient. You can see, they’re both balancing out each other in the opposite direction. So we need to understand and explain this. Use as much technology as you can to show to the patient that right now your crystalline lens is working to accommodate your natural astigmatism on the cornea.

But the monofocal lens cannot do this. So the patient finally opted for a toric lens, he took our advice, and here is a postoperative picture. Again, you can see this is another patient, but just to drive the point that the blue bar, which is the corneal astigmatism, a pseudophakic eye with a toric lens, is beautifully balanced out by the toric IOL.

So I think in trying to convey or talk to the patient using as much visual technology as you can also is very important. Nothing can beat a good chair time and discuss — like I said, I come from a place where the family is also very important in making the decision. And also in the postoperative outcome.

So I think this is what came out from the survey that I showed in the beginning. That the cost and lack of training are important. So I think that is something we can work on.

And I want to just put this last case of a share broker. He does a lot of stock market. And he has always been myopic and has myopic astigmatism. He wants to continue reading without glasses after his cataract surgery.

So what he wants is: Unaided good reading vision. So even with a toric lens, you can always correct the astigmatism and leave the patient myopic to the tune of about 2.5 diopters. And this is what we did for him.

This is the IOL calculation from the Barrett formula. And he ended up — both eyes, the target that we wanted. But he’s so happy. Because he can read without glasses.

He still wants to wear his distance vision glasses. Like Dr. Ambati nicely said it’s not 20/20. It’s happy/happy. What the patient wants and what you want should typically be in line with each other.

And my final slides… You do need to tell them that we cannot ensure a zero astigmatism. We might need a touch-up in the form of a rotation or repositioning. This is not a completely mathematical process. And every eye can behave differently.

And I think the last point I want to make is that if you want more happy patients, the team should be geared up, and their body language, their confidence should show. And that’s why training your team and showing them how your toric IOL patients are doing will go a long way in ensuring happy patients.

And trust me, this is a very forgiving technology. So I think at this time, we all push more and more toric lenses for our patients. Thank you.

DR AMBATI: Thank you very much, Dr. Vasavada. That was a terrific opening presentation. I really appreciate your point about educating the patients. And what I realized just in the last few years is that even many referring doctors don’t tell patients they have astigmatism. And if it’s the surgeon who is first informing the patient they have astigmatism, that trips up the conversation.

That adds another level of education. So the more you can have staff and referring doctors bring the patient up to speed that they have not just cataract but also astigmatism, and specifically astigmatism on the cornea, then the easier your job becomes.

So there’s a few questions in the Q and A. So first for Dr. Vasavada. What are the minimum imaging modality requirements for toric IOL selection?

DR VASAVADA: So I think this is a great question, that not everybody may have access to everything. In my understanding, when you’re starting off, what you need is a good keratometry. You could have a good manual keratometer, an optical one… These associated devices do a great job. But even if you don’t have access to that, you’re starting with an immersion A scan for a good lens.

A well done manual keratometry, and if your mires are irregular or astigmatism is below 0.75 or more than say 2.5 diopters, that’s a time when I think performing a corneal topography or Scheimpflug imaging becomes important. But I think it will go a long way. Today if you have one biometer, a good one, along with topography, you’re pretty much set.

But it should not dishearten people in parts of the world where you may not have access to all the technology.

DR AMBATI: Perfect. Next question was: What are your suggestions on what to include for informed consent for toric lenses.

DR VASAVADA: I think this is something that’s really, really relevant and important in today’s time. What we include in our consent is that we are trying to improve the quality of your vision.

We never say we are giving you “spectacle-free vision” for distance or for near. We say that we’re trying to correct or reduce your corneal astigmatism.

You may still need touch-up procedures. And you may still need occasional glasses, despite the use of toric lenses. And this is not 100% guarantee for spectacle-free distance vision. I think these are the four points I do include.

DR AMBATI: Okay. And getting back to the imaging, the next question is: Why is there a difference between Pentacam and IOLMaster and Lenstar? I just want to say that in our practice, we average a lot of different modalities.

We have astigmatism measurement from optical keratometry, Scheimpflug, and from biometry. So averaging really seems to help our practice. What do you do with your patients?

DR VASAVADA: Like you said, we also look at Scheimpflug, the keratometry, aberrometry, and you really can’t have the same reading from all three devices, which we need to understand. But if you have in the range of half a diopter and axis within 3 diopters of each other, then you are okay.

For me, today, my go-to instrument is my keratometry, for both magnitude and axis. But I always look at the posterior cornea from the Scheimpflug, and the regularity of the astigmatism. Which I do on both aberrometry and Scheimpflug. I have access to the Argos biometer, and I used to use the Lenstar. That too was fantastic.

Once you do a few cases, we should look at more than one instrument. But use one as your primary, and then two others to sort of match or corroborate. If they don’t match, if there’s a huge variation, then I want to call in the patient again. Repeat all the readings. And then sort of average out.

DR AMBATI: Yeah. Terrific. Yeah. I mean, definitely when there’s disagreement between devices, optimizing the surface and treating the patient for dry eye, and repeating the measurements is critical.

Next question is: What amount of astigmatism would you consider significant surgery induced? Surgeon induced astigmatism?

DR VASAVADA: So fortunately with most of us who now use 2.2 or 2.4 clear corneal incisions, our induced astigmatism has gone down drastically. But anything more than 0.15 diopters is significant.

So you should factor that in. And like I said, it’s a good exercise. To at least know what you’re inducing. Because sometimes you might be surprised. Pleasantly or otherwise.

DR AMBATI: Perfect. And I think we’ll do one last question from the audience. How long will you treat patients with ocular surface disease before repeating the keratometry?

DR VASAVADA: In an ideal world, I would like to have at least 10 days or 15 days to 2 weeks. But it really depends on how bad the ocular surface is. If it’s something where even after giving lubricants for a couple of days you don’t get reliable mires or readings, I will ask the patient to wait for two weeks.

But usually in the setting where I practice, in private practice, patients are on shorter deadlines. So I think a couple of days usually works for most cases.

DR AMBATI: Perfect. Well, thank you very much, Dr. Vasavada. I really learned a lot. And our next speaker is Dr. Jerry Hu from Texas Eye and Laser Center, in the Dallas Fort Worth area. I’ve known Jerry for over 22 years.

And I’m very excited to hear his talk. It’s all about the measurements. What is my current pathway for calculating and selecting my toric lens?

And managing posterior corneal astigmatism. Jerry, thank you for joining us.

DR HU: Yeah. Can you guys hear me? You can? Okay. Great. So let me grab my mouse. All right. So thank you, Dr. Ambati, for the kind intro and invite.

Let’s see. So I do believe the ability and the practice to precisely measure astigmatism really lays the foundation to any effective treatment. Including lens-based approaches, such as toric IOLs or corneal-based approaches, such as femtosecond laser, AK, or ocular keratometry.

In the next 15 minutes, I’ll show you quickly how I calculate and select toric IOLs, and how I manage and handle posterior corneal astigmatism and how I plan femtosecond laser ocular incisions.

My disclosures. So this is a real live patient who came in last week. 60-year-old guy. Best corrected vision, 20/40 and 20/30. Confirmed to have 2+ nuclear sclerosis.

I did his right eye last Thursday. So I’ll just focus on his right eye. So his corneal topography, his autorefraction, manifest refraction, his autokeratometry, and biometry all showed relatively small against the rule astigmatism.

So my question for the audience is: How would you manage this patient? Now, remember, three out of the four or four out of the five devices showed relatively small against the rule astigmatism. So here are the choices.

So one is do nothing. His astigmatism is kind of small. He may just see well without doing anything special. And the second is do a manual limbal relaxing incision. Three, a femtosecond laser arcuate incision.

Or toric implant. Or maybe a combination of two or more of the above. Do we get to see a poll response? Oh.

Very good. Looks like the number one is the manual relaxing incision. I think the patient would do very, very well with that. And femtosecond laser — that’s a surprise. That’s the lowest. Maybe that’s due to the availability of the technology.

So let’s see what we did. Let’s move on. So it’s always a good idea to take a thorough history. You know, we all have had patients who conveniently forgot to mention their LASIK 25 years ago. Right?

And of course, education and planning before the surgery and hand holding after the surgery are every bit as important as the surgery itself. Cataract care is still complete eyecare. If a patient’s astigmatism is caused by a certain ocular pathology, like keratoconus, or corneal scar, we can still help the patient.

But we may have to modify our approach, accordingly. So the patient’s current eyewear prescription and current manifest refraction can provide valuable clues. Although the true extent of the corneal astigmatism is often masked by their underlying lenticular astigmatism.

Just how common is lenticular astigmatism? It’s very common in most of the patients. 85% of us, you know, we have some degree of lenticular astigmatism. They’re usually irregular. Okay?

And they tend to increase with age. But fortunately, they will be gone along with the cataracts. Lenticular astigmatism is usually also pretty small in magnitude. Unless they’re caused by certain underlying diseases.

But the good thing is they’re generally quite rare. So it’s all about the measurements. How do I take corneal measurements when I see my patients? Well, I use autokeratometry and corneal topography on all patients.

I also get a corneal tomography with Pentacam on many patients, especially if they’ve had previous refractive surgery like LASIK or PRK. Or if they’ve had any corneal altering surgery like pterygium surgery or if they have any corneal pathology.

Pentacam is really indispensible in my practice. In cases of previous LASIK, where only the central cornea is flattened. I can render a special report with Pentacam. And see corneal curvature readings, in certain optical zones.

For example, this is a previous LASIK — myopic LASIK case. And as shown in the picture, I take K readings at 4.5 millimeter optical zone.

And also biometry has improved a great deal over the years. I’ve used Lenstar, IOLMaster, and Argos in my practice. Currently my go-to biometry in routine cases is IOL Master 700. It’s a swept source OCT. The true keratometry feature claims to be able to measure central cornea and posterior corneal curvatures much better.

So most patients have posterior corneal astigmatism. Almost invariably, against the rule. Some may have more significant amounts than others. It’s not uncommon to see patients with half a diopter or even 1 diopter cylinder on the posterior surface. Until recently, nearly all keratometers could only measure the anterior corneal surface, not the posterior.

Against the rule astigmatism tends to increase with age. And an average patient has about 14% more against the rule astigmatism than what can be shown on their measurements.

So currently, and for the last 15 years, I’ve relied on ORA, which provides intraoperative aberrometry to improve visual outcomes with IOLs, as well as postcornea surgery cases and other cases. As the new IOL formulas improve, some of my colleagues have stopped using ORA. Well, I’m still getting great results with ORA. My enhancement rates for the advanced technology is only about 1% or 2%. When I use ORA.

And when I stop using ORA, my enhancement rate goes up to 9% or 10%. So I’m still sticking with it. But my approach might change in the future, depending on the technology. So limbal relaxing incisions have been used effectively for many years to reduce corneal astigmatism.

Recently, digital marking devices such as Callisto, shown here, have improved the accuracy of this approach. Femtosecond laser has allowed us to be more aggressive, and even more accurate.

When we move relaxing incisions from limbus centrally to non-limbal optical zone, or even smaller as needed. There are different normograms for where and how long these incisions should be. My own rule of thumb is about 30 degrees arcuate incisions for every half a diopter, and 9 millimeter optical zone.

So for 1 diopter astigmatic correction, for example, I like to make a pair of 30-degree arcuate incisions at 9 millimeters. And of course… Let’s not forget LASIK or PRK, as valuable options in our tool box as well.

So in addition to a cornea-based approach, we now have lens-based options for the last 15 years. Toric IOLs have become a mainstay in my practice. Every single category of IOLs now offer toric models.

Including monofocal, multifocal, extended depth of focus, and of course, light adjustable lenses. And Dr. Doane will teach us more in depth on the light adjustable lenses. So let’s go back to our patient from last week, our case study.

So the patient desired a multifocal IOL to expand the range of his vision. So from the IOL Master 700 printout, I first selected the spherical power of 20.5 diopters.

Aiming plano. And then I decided on a toric model, T3. So how did I do that? Well, there are a plethora of online toric IOL calculators. From ASCRS, ESCRS, Asia Pacific ACRS, and every IOL manufacturer. You can use any of them, pretty much. With good outcomes. Which one do I use? I happen to use none of them.

Over the years, the two main families of toric implants I use, from Alcon and also the Tecnis family, from Johnson & Johnson, I have committed their power tables to memory. And I just do my own calculations.

So for this patient, I predicted a Panoptix T3 model with a power of 20.5 diopters. So this is the video of the case from last Thursday. So I’ll just play the video.

>> Here I’m doing a small 5 millimeter capsulotomy to keep the optic in the bag. I do a 4.8 millimeter capsulotomy when I use femtosecond laser. Gentle phaco. Cortex removal. I polish a lot. I spend more time polishing than phacoing, arguably. Refill the anterior chamber with OVD to an intraocular pressure of 20 to 25. Confirm with a tonometer. Make sure it’s not too firm or too soft.

ORA intraoperative aberrometry. Aphakic wavefront refraction reading. I take 3 readings. Each one has… For the measurements, I pick the best one. Here I’m selecting the spherical power, target plano, and with that… I select the toric power. In this case, it’s a T4 instead of T3.

This is not uncommon. Especially considering this is against the rule astigmatism. The toric models often go up from the preoperative calculation. I remove OVD completely. Especially behind the optic, to prevent the IOL from rotating. ORA will then give me placement guidance, as to where to align the toric IOL.

And I leave a little hypotony to collapse the capsular bag, to stabilize the implant. Here I’m doing a small 5 millimeter…

DR HU: All right. So within the first week after implantation, you know, some toric IOLs may occasionally rotate spontaneously.

The rotational stability of toric IOLs is very good nowadays. With the current models on the market, I’m seeing maybe a 1% or 2% rotational rate. As long as the spherical equivalent is on target, it’s actually quite safe and easy to rotate a misaligned toric IOL.

It spares the patient from needing a LASIK, which could make their dry eyes worse. I have done it up to a year post-op. But if you rotate within 1 to 3 months, you can simply reopen the paracentesis with a Sinskey hook. Then you use cannula or BSS syringe to rotate the lens. There’s no need to open a corneal incision and there’s no need to use any OVDs. So it takes a couple of minutes.

And not much inflammation. The patients can see well almost instantaneously. The website, astigmatismfix.com, provides great guidance and step-by-step instructions for this maneuver.

So I would highly encourage all of you to incorporate toric IOLs into your daily practice. It’s both rewarding and forgiving. You don’t really need to be perfect. You don’t have to completely eliminate their astigmatism to make patients happy.

You just need to debulk it. You can use toric IOL, you can use femtosecond laser arcuate incisions, or you can simply do a manual limbal relaxing incision. So the audience response — all the answers are correct. You can help this patient really well in a number of different ways.

So as long as you do something to address patients’ astigmatism, both you and the patient will be amply rewarded. So the old adage: Close enough is good enough actually does ring true in this scenario. Thank you for your attention, and I’ll be happy to take questions.

DR AMBATI: Thank you so much, Jerry. Terrific talk. I really enjoyed the video. When do you decide you go with femtosecond AK versus a toric lens? What situations do you pick which?

DR HU: Well, if it’s under 1 diopter, for with the rule, for with the rule astigmatism, I anticipate the final… The true astigmatism would be less. You know.

So I would be more inclined towards doing the femtosecond laser. So basically if it’s 1 diopter or less with the rule, I go with femtosecond laser. And if it’s 0.75 diopter or more against the rule, I anticipate the true astigmatism will be more than 1. So actually, I would tap into the toric.

DR AMBATI: Terrific. We have a couple of questions from the Q and A audience.

Do you undercorrect with the rule and do you overcorrect against the rule astigmatism?

DR HU: Yeah, that’s a great question. I think one of the well known studies in pilots, in astronauts, actually, have shown that patients who actually see more than 20/20, right? 20/15, 20/12, 20/10, they actually have a slight amount of vertical astigmatism.

So that actually helps to improve the visual perception. So yes, indeed, I undercorrect with the rule and I tend to be more aggressive and overcorrect against the rule. That’s a great point.

DR AMBATI: So are you shooting for about a quarter of with the rule astigmatism?

DR HU: Yeah. I don’t have to… If the 2 power recommendations straddle the perfect target, I just go with, you know, one power under for with the rule and one power over for against the rule.

DR AMBATI: Gotcha. Next question from the audience was: What’s your favorite toric IOL? Alcon, J and J, Bausch and Lomb?

DR HU: Well… Actually, we have just done a study comparing the Clarion toric platform and the Tecnis… The Eyhance Tecnis 2 platform. It’s a very well done study. And we actually… You know, the outcome is dead even. I’ll just say that. It’s dead even. They’re both very good. The rotational rate in that particular study was well in the 1%. More like… Under 0.5% rotational rate.

So they’re very, very good. The mechanism is different. The Tecnis 2 has frosted haptics. I think it’s really intuitive that it’s stable in the bag. It’s actually difficult to even rotate in the bag. In surgery. Whereas the Alcon platform, it relies on the fibronectin formation. It takes more technique. But with the right technique, if you leave it hypotonous, collapse the bag so it’s around the haptic, you can get really good stability.

DR AMBATI: That’s a good point. We’re used to keeping a hard eye at the end of the surgery to minimize leak, but actually, we may want to lower our end intraocular pressure to help optical recovery, as well as help keep the lens more stable. That’s a terrific point.

The next question is: How does one calculate their surgeon induced astigmatism? Are you keeping track of all your cases?

DR HU: Yeah. Yeah. We’ve done that… You know, I would highly recommend all the surgeons in the first maybe five years to really keep track of it. And also as your technique changes, as you modify your technique, always do another tracking.

So I think 20 years ago, you know, my surgeon induced astigmatism was more like 0.2. But now with 2.2 millimeter incision, really limbal — paralimbal, not really clear cornea — so it’s really 0.1. So for all practical purposes, I program 0.1. But it’s negligible.

And also, a lot of surgeons actually advocate operating on-axis. I personally — you know, I did that for years. But now for the last maybe 15 years, I’ve chosen to operate off-axis. Because I want to preserve the axis.

To future intervention. Manual limbal relaxing incision can be the — under ORA guidance, under intraoperative aberrometry guidance — can be done at the end of the surgery. And I want to preserve the axis to be able to do that.

So I in fact make my incisions around the axis. I leave the axis untouched. Just for that reason.

DR AMBATI: Gotcha. How many degrees of axis rotation would you consider for postcataract surgery rotation of the lens? When would you intervene?

DR HU: Oh yeah. So pretty much — they rotate usually within the first week. Occasionally in the second week, I’ve seen a couple. But usually within the first week.

And by one-week post-op, you would know if you’re gonna rotate or not. But I usually always wait ’til about 1 month out. Because I want to get a good refraction. The ease or the difficult level of doing the rotation is the same at one week or one month.

So at one month, I’ll be able to know the true manifest refraction. If there’s any spherical error, then rotation would not help you. Then I’ll go to LASIK or PRK. But if the spherical equivalent is neutral, then I can go in at 3 or 4 weeks, or even later, and as long as you do it within the first couple of months, you can open up the paracentesis, do a very easy rotation, in a couple minutes you’ll be out of there.

And because you haven’t done anything, you haven’t opened up the wound, you haven’t done OVD, there’s minimal inflammation. And the patients can actually see within hours.

DR AMBATI: So when you open up just the paracentesis and you’re using your BSS cannula, are you using a 27 or a 30-gauge? Are you using the long cannula, short cannula?

DR HU: Right. You can do either one. I’ve used 27. And the 30 — yes, I’ve done both. Yeah.

DR AMBATI: And next question from the audience: Would you do toric lenses without a topography?

DR HU: You know, it’s not just one topography. We have… On my desk, I have five different keratometry readings. The topography — some kind of topography, tomography, K readings, like I said, refraction also can give us a clue.

I would hesitate — and also the ORA, you still need to — even if it’s postoperative aberrometry, you still need the preoperative axial length and the K readings in order for ORA to work.

So I cannot think of a scenario where I would go in blindly and do a toric lens without topography. I would get more than just topography. Several different modalities of the K readings.

DR AMBATI: Yeah, I totally agree. I think it’s very important to measure two or three ways. And then do that before cutting. So I think having the best measurement is critical. I am surprised by how many cataract surgeons don’t have a topographer. And that’s probably because I’m biased, coming from a corneal refractive fellowship, as you are.

But I think it is critical to get those topographic measurements. One last question from the audience. What measures do you recommend to reduce IOL rotation during surgery?

DR HU: So I have mentioned a few. The number one is smaller wound. So I use 0.9 millimeter paracentesis, 2.2 millimeter main corneal wound. The second is a small capsulotomy opening. I used to make it bigger. But as I progressed further, my capsulotomy opening is just getting smaller and smaller.

So I use a 5.0 millimeter manually, and I use 4.8 with femtosecond laser. And some of my colleagues, they are even doing 4.5. I think that helps. I polish a lot. You know, some of my colleagues, they leave a little lens epithelial cells there. They think the fibrosis will help stabilizing the implant. For me, really, the fibrosis, the traction, the tethering can really change the effective lens position later on.

So I polish a lot. Copiously. I spend more time polishing posterior capsule, anterior capsule, in the periphery, more time polishing than phacoing. And so that’s another thing. Because the mechanism of the modern generations of toric IOLs do not need all those fibrosis to lock it down.

And finally, I leave the eye pressure very low. I burp the eye. I really collapse the capsule around the haptics. So it’s not gonna move. And of course, I tell the patients: Don’t do any — don’t run. Don’t jump. Refrain from strenuous activities for one week.

And with that, still some patients, you know, you’ll still see some rotation. So that’s why it’s very important to have the tools, to have the skill set to deal with that. Having said that, I’m seeing about 1%, 1 to 2% rotational rate. But again, close enough is good enough. Even if they do rotate 5 degrees or 10 degrees, for lower power toric lenses — patients will still do very well.

But if it’s a higher power, the T5, T6, even a 5 degree rotation will make a big difference. Patients will tell you… Yeah.

DR AMBATI: Absolutely. That’s a very important point. The amount of significant rotation depends on how strong the toric correction is.

Well, thank you so much, Dr. Hu. I really appreciate your wisdom. And we’ll move on to the next speaker. It’s Dr. Dagny Zhu from California. She’s going to speak about execution. Tips and tricks for toric surgery techniques.

Dagny, welcome. Thank you.

DR ZHU: Thank you so much. Let me just pull up my slides here. Okay.

Hopefully everyone can see my slides okay. Thank you so much, Dr. Ambati and to Orbis Cybersight for inviting me to speak. So I’m gonna talk a little bit about, now, the execution of astigmatism management.

Specifically some tips and tricks that you can use for toric IOL surgery. And these are my disclosures. So why do we even care about getting that toric IOL perfectly aligned?

So Dr. Hu alluded to it earlier. This is a nice table that tells you more specifically what to expect when you are misaligned. So every 1 degree of misalignment of a toric IOL leads to about a 3.5% undercorrection of the patient’s astigmatism. So that means that if you’re off-axis by 10%, you are uncorrecting that astigmatism by 35%.

And once you are off-axis by 30 degrees, you’re essentially canceling any astigmatism correction altogether. Obviously even greater degrees of misalignment can cause you to induce worse astigmatism than the patient even started with.

So it’s extremely important to make sure that that IOL, that toric IOL, stays where you want it to. So overall, there are three steps for successful toric IOL implantation. You want to be able to identify and locate a horizontal reference axis.

And then during surgery, you want to locate that steep axis, where you want to align the toric IOL. And then obviously, finally, you want to make sure that you properly align that toric IOL along the steep axis and make sure the IOL stays there.

So conventionally, when we’re making those preoperative reference marks, you can do this manually, just by simple visualization. Have the patient sitting up. And usually I have the patient have both eyes open.

Looking in the distance over my shoulder. And what that does is it prevents the patient’s eye from converging. And it also will allow for the patient to be looking straight without any cyclorotation of the eye. Because we know that when the patient is lying down, the eye tends to cyclorotate.

And it can throw your axis off. Most patients have over 2 degrees of cyclorotation. Some patients have even more. So whatever you do, make sure the patient is looking at a distance target and sitting up when you’re doing these marks. You can use a slit lamp and a horizontal beam of light to increase the accuracy of where you place those 0 and 180 degree marks.

Conventionally, we can then take the patient into the OR, and when they’re lying down, we’re gonna use a toric axis marker to line up to the 0 and 180 degree marks that we made, and we make a third mark at the steep axis. Which is where we want to align that toric IOL.

So that’s the traditional method. But of course now we’re living in a digital age. So almost everyone has a smartphone these days.

What is it that a smartphone can’t do these days? So every smartphone has a gyroscope integrated. And so what this allows is that we can actually hold the phone using the camera setting in front of the patient’s head.

And make sure that the patient’s head is actually properly aligned and level. And so that better assists us to mark those 0 and 180 reference marks with greater precision. The other thing that this app can do — and there are many different toric IOL apps available now — is that it allows you to take a picture with the overlay of an axis marker.

So that you can even line it up to a landmark on the patient’s eye. For example, a nevus or a prominent blood vessel. And it will automatically calculate the angle between that landmark and the steep axis where you want to align the toric IOL.

And then you can take that picture intraoperatively and use that to guide the alignment while you’re doing surgery. So potentially you don’t even need to mark the patient at all, manually, preoperatively. So many companies have taken this to the next level and incorporated digital visualization for better toric IOL alignment.

So in these cases, you don’t need to mark the patient at all. And that’s because if you take a reference photo with the patient, again, sitting up, the software will identify the limbal blood vessel anatomy of the eye and it can determine the reference axes based on that.

So that when the patient lies down on the bed, under the microscope, it can compensate for cyclotorsion, and know exactly where the 0 to 180 axis is, and it can overlay an image in your microscope that tells you where to align the torics. So in the bottom right corner you can see the yellow line is where the 0 and 180 axis is, based on the patient’s limbal blood vessels from where they were sitting up, and the blue triple line is the steep axis of corneal astigmatism.

And where you should align that IOL. So it has increased precision. Exponentially, in many cases. Thanks to digital marking. And then Dr. Hu spent a lot of time talking about intraoperative aberrometry. That’s another method of helping you to choose the correct toric IOL power and also to properly align it during surgery.

And this is an aphakic refraction. So you do need to make sure that the eye is at the correct pressure. The ocular surface is well lubricated, and the patient is fixated at a light. And so many of these factors can be difficult to control. So sometimes it can be difficult to get an accurate reading.

But obviously, if you’re an experienced surgeon like Dr. Hu, you’re gonna get even more precise outcomes. For me, I don’t use intraoperative aberrometry. It’s not necessary or mandatory to get excellent outcomes.

But it can be helpful in many situations, especially postrefractive cases, in which IOL calculations can be a little bit less precise. So this is actually the method that I use for toric IOL alignment. In my practice — and I’m in Southern California — I’m actually doing femtosecond laser assisted cataract surgery on all of my cataract patients.

And the femtosecond laser that I use has iris registration built in. In which, again, you take a preoperative reference image. And instead of looking at the limbal blood vessels, it’s looking at iris landmarks. And so when the patient lies down, again, under the laser, it’s able to compensate for cyclotorsion.

And it identifies visually the steep axis by making these little notches or tabs in the capsulotomy. So when it makes the circular capsulotomy, it leaves the notches right at the steep axis. So in the OR, you can see under the microscope exactly where those notches or tabs are.

And that’s where you want to line up the toric IOL. And it’s great, because it can also show you very easily postoperatively if an IOL has rotated. Because it will no longer be aligned with those little tabs. It’s also great for more precisely grading the arcuate incisions or the AK incisions at the precise axis, as well as the clear corneal incision.

I program it to be around 10 degrees in the left eye. Sorry. 10 degrees in the left eye and 190 degrees in the right eye. Had to think about that. So that every clear corneal incision is made at the exact same diameter, depth, and axis.

So that I can really standardize and uniform my SIA. So here is a live video of a case I did a few weeks ago, a brunescent cataract with an against the rule astigmatism. You can see the femtosecond laser makes the capsulotomy with the little notches or tabs at that 0 to 180 against the rule axis.

And then obviously it helps to fragment the very dense nucleus. Which greatly assists me in surgery. When disassembling that nucleus. And it makes the clear corneal incision as well at the same place, same depth, every time.

This is a separate case. So we all know that with multifocal IOLs, it’s even more important to correct astigmatism. Because you know, a little bit of residual astigmatism, even as low as 0.75, can greatly degrade the patient’s visual quality.

So this is a trifocal IOL case, and you can see how beautifully the preoperative plan matches the postoperative result. It’s a little hard to see, but you can see the little tab in the capsulotomy and see the toric IOL is perfectly aligned where I want it to be.

So it’s no surprise that there are many studies showing digital markings offer an even higher level of precision. But I think even if you do just very good and careful manual markings with the patient fixating on a distance target, you can still get a great outcome.

So it was interesting that Dr. Vaishali did her poll and showed that about 20% of the viewers right now currently are not using a toric IOL. So I’m just gonna show this basic surgery video on how to insert and properly align a toric IOL.

So you can see here… Let me see. It’s a little bit difficult to see. But this is a post-RK patient. Oops, sorry. Let me go back. Okay. So there’s this little tab here on the capsulotomy. There are the two tabs right there. So I’m using a toric IOL in this post-RK patient.

Now, I have made sure that astigmatism here is regular and consistent. So I did two topographers, two biometers, and it was all in agreement. So surprisingly, this patient had relatively regular and symmetric astigmatism that agreed on four different devices, in terms of magnitude and axis.

So I was very confident in planting a toric IOL in this case. Topography is essential to make sure the patient’s astigmatism is regular and a good candidate for IOL implantation. So here I’m injecting the IOL.

And you’ll see that what’s important here is I’m actually leaving the IOL slightly underrotated. So the tab is right here. This is the mark. So I’m leaving it slightly counterclockwise. Because I know that when I remove the OVD, the lens tends to rotate clockwise.

So you can see I’ve left it slightly counterclockwise. And when you go in with your I and A tip, what’s important is that we remove all the viscoelastic. And that’s what’s going to minimize postoperative toric IOL rotation.

So you want to get all the viscoelastic on top of the lens but also behind the lens. How do you know you’re getting it behind the lens? You see the lens just jumped and jiggled there? That’s how I know I got all the OVD behind the lens. You can go underneath, but I don’t need to when I use this technique of tapping the lens. And then you can gently nudge those toric markings towards the axis of the intended alignment.

And there I’m pretty happy that the IOL is where I want it to be. And so I go ahead and end the case and seal the wound. So… Just a summary of my pearls. You want to make sure that you’re implanting it slightly counterclockwise from where you want it to be.

And after removing the OVD, you want to use the IA tip to nudge that optic or that toric IOL into the proper axis. So in order to minimize post-op rotation, again, remove all the OVD, viscoelastic, you can push gently on the IOL to get all the viscoelastic from behind the IOL, use a cohesive viscoelastic, when you are inflating the bag, because if you use a dispersive, it’s gonna be really difficult to remove that viscoelastic. The cohesive viscoelastic

is a lot stickier and larger, and they tend to come out more easily in clumps. And it’s easier to aspirate out. As Dr. Ambati mentioned, you want to underpressurize the eye at the end of the case. Because that allows the capsule to better hug the IOL, and to minimize postoperative rotation.

As Dr. Hu mentioned, do extensive polishing. I actually use a shepherd’s hook, a separate instrument, to completely polish underneath that anterior capsular rent. And studies have shown that the most common reason for postoperative IOL rotation in the late postoperative period is due to capsular phimosis and bag contraction.

And that’s because you’re not cleaning up the lens epithelial cells. Most commonly, though, what we see is that if any rotation is to happen, it usually happens within the first hour to ten days post-op, and that’s because of retained viscoelastic.

Finally, a final point. You’ll find that in some eyes, it is difficult to keep the IOL where you want it to be. It tends to rotate. And this usually happens in highly myopic eyes with enlarged bags. And so in those cases, you can consider inserting a CTR or capsular tension ring, to mechanically keep the toric IOL in place.

And that’s happened to me before. I kind of learned that the hard way. I used a CTR, because I noticed there were some loose zonules, and I wanted to increase bag stability. And when I inserted the toric IOL, I didn’t rotate it quickly enough. And when the haptics unfolded, it actually became very difficult to rotate with the CTR in there.

So if you place this, make sure that you rotate quickly. Before the haptics open. But it definitely adds to IOL stability. And then the other thing you can do is actually, in rare cases, where you’re going back in to realign the IOL, but it continues to rotate, a nice way to make sure that it doesn’t rotate again is just to reverse optic capture the IOL.

So that just means leaving the haptics of the IOL in the bag and popping the optic above the capsule. So that’s kind of a neat trick to use in rare cases where that toric IOL does not stay where you want it to. So what happens if you have a patient with residual astigmatism, postoperatively, that’s a surprise and unexpected?

First of all, you want to make sure if the toric IOL rotated. Is that the cause? And it’s really easy to see when you have the capsulotomy tabs whether the toric IOL rotated. But sometimes it’s not that easy to tell. And so astigmatismfix.com is a great website to help you figure that out. And also guide you on how you should rotate the IOL.

So you basically just input all the data that you have in terms of what type of lens you place, what power it was, what the toricity was, what was the IOL axis you were aiming for, and what is the current IOL axis, which the lens is sitting at now. And the most important part is entering the patient’s current refraction.

So you can see that this patient has residual 4 diopters of astigmatism. But what’s important is that the spherical equivalent is plano. And so that means that potentially you could rotate the lens to cancel out the astigmatism.

If your residual spherical equivalent was -1, +1, a rotation of the lens is not going to help you. You’re better off exchanging that lens to get a better more accurate spherical power. So we input all that information, and then the website actually tells you… Well, if you rotated this lens 40 degrees clockwise, you would be able to minimize the astigmatism.

But we actually can’t get it to a point where the astigmatism goes below 0.75. So in this case, they’re actually recommending that you exchange the lens. Probably for one of higher toricity that would better be able to correct the patient’s residual astigmatism.

So a super helpful calculator and tool that you can use to figure out how to fix your patients with residual astigmatism after toric IOL surgery. So really quickly — what about LRIs and AKs? I know there are parts of the world where you may not have axis to toric IOLs or patients may not want to pay out of pocket for it.

LRIs and AKs are still a great option for astigmatism correction. And the main difference is that LRIs are placed more peripherally, at the limbus, whereas AKs are more centrally, usually about 8 to 9 millimeters in diameter. And the great thing with AK is you can create it with a femtosecond laser.

That’s what I do, because it offers greater precision and stability. So what’s important to know is that any arcuate incision is always going to have greater effect in older patients. So you can use shorter arc lengths in older patients and longer arc lengths in younger patients for the same amount of correction.

Really, really important to avoid any arcuate incisions in irregular eyes with underlying ectasia or keratoconus because you risk further destabilizing that cornea and causing worsening astigmatism. And both are still less predictable and less stable than a toric IOL.

So I would still use a toric IOL if a patient has a minimal level of astigmatism. And if that is available to you. So here’s a poll for you guys.

What is your preferred method for managing with the rule astigmatism in a cataract patient with 0.75 diopters of cylinder?

This is similar to Dr. Hu’s question, but his was against the rule. This is with the rule. Remember, with the rule, we tend to undercorrect a little bit. So this is a very small amount. So what are your options here?

Would you perhaps operate on axis? Create a manual LRI or AK? Do a femtosecond laser LRI or AK, implant a toric IOL, tell the patient they will need postoperative laser vision correction, tell the patient they need glasses or contacts, or there’s no special correction needed for this patient because it’s such a low amount.

So take a few seconds to vote here. Many different options.

All right. As expected… It’s kind of dispersed throughout. But it looks like the most common answer is operate on axis followed by using a toric IOL and no special correction is needed.

So for me, I think that operating on axis is a perfectly good solution. Because like I said, it’s a very small amount of astigmatism.

There’s really no toric IOL available that will correct that low level of with the rule astigmatism. So I would not implant a toric IOL. I do think an LRI or AK is a good option as well.

And for those who answer no special correction needed, I think that’s okay, if you’re implanting a monofocal IOL. But remember, when we are placing our incision temporally, we’re actually worsening the with the rule astigmatism as well. So you could potentially be causing 1 diopter or more of with the rule astigmatism.

So that can be significant, even for monofocal IOL. So I would say I would still try to correct this low level as much as we can, to get patients the best outcome possible. Especially for multifocal IOLs, but even monofocal.

So… We actually asked this question as part of ASCRS in the United States back in 2019. And these were the surgeons’ responses in the US back then. And you can see the majority chose on-axis incision operation.

But still, 17% said no special correction was needed. So I think there’s still some education even in the US about needing to manage even low levels of astigmatism.

So based on this data, when should we be using arcuate incisions versus a toric IOL? You can use these tables as references. But for me, I tend to use a toric IOL for against the rule astigmatism, 0.75 diopters or greater. That usually corresponds to a T3. And I’ll use toric IOL for with the rule astigmatism, 1.25 diopters or greater.

And again, that’s because of the posterior cornea. It tends to give patients greater amounts of against the rule astigmatism. Because of that — against the rule posterior cornea astigmatism. So that’s why you would always overcorrect against the rule and undercorrect with the rule.

And for anything less than that, I’m using my femto AKs. I’m not using femto AKs for anything greater than 1.25. I’ve noticed if you’re making arcuate incisions above 1.5, and it’s central, those can destabilize over time. So I try to minimize arcuate as much as possible and go with toric IOL.

So you can see the majority of eyes have low levels of astigmatism, less than 1.5. But even a large portion of those patients can do well with a toric IOL, especially with those, again, with against the rule astigmatism. But you can also use arcuate incisions, depending on what is available in your part of the world.

And still have an excellent outcome. So additional pearls — we talked a lot about SIA. Make sure you track it. If it’s a small incision, it’s usually negligible. For me, it’s about 0.1. Always make paired arcuate incisions, rather than a single large one. Again, to avoid destabilization of the cornea.

And you can even pair toric IOLs with arcuate incisions to treat cases where you have higher levels of astigmatism. So the majority — I think our toric IOLs in the US, they basically correct a maximum of 4 diopters of corneal astigmatism. But multifocal IOLs, they correct only up to 2.5.

So on the bottom image I have a trifocal lens. I’m pairing the toric IOL with AK to correct the astigmatism greater than 2.5. On the left side, it’s a highly myopic eye. I had to use a high power three piece lens, which do not come in a toric option, and I paired it with AKs to correct that astigmatism.

A quick note on operating on axis. Most surgeons now are doing a temporal phaco incision, just for easier access and because it’s not as central. The patient’s horizontal diameter is wider than their vertical diameter.

So actually, minimizes your SIA. So remember, that for against the rule patients, if you’re operating temporally, it’s great. It’s gonna reduce the against the rule astigmatism. But for the with the rule astigmatism patients, operating temporally will worsen the with the rule astigmatism. It’s something to keep in mind.

Typically it can do so up to 0.5 diopters. But if you don’t have a toric IOL available, arcuate incisions are not possible, you can do a pair of clear corneal decisions on axis to potentially reduce a patient’s astigmatism up to 1 diopter. Something to keep in mind.

Really quickly, some of our next speakers are gonna go over the different types of IOLs that you are also use in more complex astigmatism situations. But we live in a great time today, where there are so many different IOLs available for different astigmatism scenarios.

Here I’m using a small aperture pinhole IOL for a post-RK patient with irregular astigmatism. And that is great for correcting irregular astigmatism. Even up to 1.5 diopters refractive astigmatism, it will null that, because of the pinhole optics.

On the right, I have a post-Intacs keratoconus patient. I like to use a zero aberration monofocal lens. Wherever possible. So as not to worsen that eye. So use a toric IOL whenever possible. There are many steps you can take to maximize precision and stability of toric IOL and your patients will thank you for it. Thank you so much for your time, and I’m happy to answer any questions.

DR AMBATI: Thank you so much, Dagny. I think we have time for just one question. What’s your preferred technique for toric marking?

DR ZHU: So for toric marking, if I’m doing manual toric marking, I use my slit lamp with the horizontal beam. Have the patient have both eyes open, looking at a distance target over my shoulder, and I will set it as 0 and 180 and mark it manually.

But in most cases now, I’m using iris registration with my femtosecond laser, so no marking is required. It will automatically identify the 0 and 180 and make those little capsulotomy marks for me.

DR AMBATI: Terrific. Thank you very much, Dagny. I appreciate your great talk. Very comprehensive.

Our next speaker is Dr. John Doane. He’s joining us from Discover Vision in Kansas City.

And John will be sharing with us his experience on light adjustable lens and Bioptics.

DR DOANE: Great. Thank you. A pleasure to be with you all this morning. I want to thank a couple of people who helped out in this presentation. Thank you for the invite, and Andy Chen and Lawrence who with Cybersight have done a wonderful job of setting the stage for everybody.

So I’m gonna go through a couple of things. A slide on toric IOLs and a slide on Bioptics, but I’m gonna spend most of my time on light adjustable lens. As the speaker said, we’ve had three approaches to treating astigmatism. Keratotomy, laser vision correction, corneal vision correction, and IOLs.

I’m a little different from many of the speakers. I abandoned corneal incisions for astigmatism 20 years ago. I found that IOLs and Excimer laser were so far superior. And the reason I say that is the stability of the correction.

Just over time, so many patients were — maybe I was treating 2 diopters of astigmatism and I followed them long enough and found out that the 2 diopters I treated, with the rule, over the course of ten years, was now 2 diopters against the rule.

So I’ve kind of backed away from incisional keratotomy, just feeling that the stability of either treating the astigmatism with the toric IOL or with laser vision correction, was superior. And I can treat really small amounts of that.

So I felt very comfortable in that sense. So I do apologize. It may be a little bit different than the other speakers. But again, I would be interested in their thoughts on what I was just saying.

So let’s go through a couple things. I’m a consultant for Carl Zeiss, and RxSight, and probably the two places that would be some crossover in this talk.

So the light adjustable lens — the technology is certainly leading edge. And we’ll get into why I think that’s the case here in just a second. It’s not brand-new. The light adjustable lens has been, at least in concept, prior to the year 2000… I got involved with the company in 2008 as an FDA investigator.

And I went through all the different trials for both spherical and astigmatic corrections. Things that are still coming to market over the last few years.

We’ve been doing commercial cases now for five years, in Kansas City, starting in June of 2019. And really the concept is as follows: We place the lens in the eye.

And we adjust whatever residual refractive error is present. In the refraction of the patient. In addition, we determine where we want to target that patient with the patient’s input.

Are we gonna do both eyes for distance? One eye for distance, and maybe one eye for near? The one great thing about the light adjustable lens is there’s built-in extended depth of focus. So we can achieve excellent distance and near vision with very small amounts of residual refractive error in the quote-unquote “near eye”.

And I would say in the vast majority of patients we treat, the near eye is still legal driving. So the adaptability to this process is much better than what we experience with either LASIK or monofocal IOLs, where maybe 30% of the patients will not tolerate the difference in power between the two eyes.

I.e., the anisometropia. And what we’re doing with the light adjustable lens — the adaptability or the tolerability is probably 98% to 99% of eyes. Where the patients — only 1% to 2% of patients will say: I really cannot tolerate this. I need both eyes at the same focal point. Where are we with current IOLs?

I would say a third of the patients we treat have a residual refractive error of 0.75 diopters or more, and another 1/3 have a residual cylinder of 0.75 or more. That’s when we’re treating say a spherical monofocal IOL. 2/3 IOL patients have imperfect distance vision.

When I say perfect, I’m talking about 20/20 distance vision. I found out that patients are not 20/20. They tend to complain of three things. Inability to see road signs and highway signs as quick as they would like, and if they’re watching TV or watching sports, seeing the score on the TV, reading names of jerseys on TVs or reading the score on the TV.

So if a patient was 20/20, they go to 20/25, they now go and complain because they can’t see those things. And at that point, I know they’re not 20/20. So it puts a premium on getting people to literally perfect vision so they will not have those complaints. What about multifocal IOLs? What issues arise there?

There is somewhat imperfect distance vision, because the quality of vision is not as good as in a monofocal optical setting. And if you’re doing multifocal IOLs, you’re actually guaranteeing halos for virtually every patient, and there’s some variability in what patients will complain about, as far as glare.

Reading vision, it can be mediocre. I wish I could say it’s perfect. Certainly is not. Maybe 60% of people love their near vision. But the others are just kind of… Even though they’re J1, they’re kind of… Eh, not so good.

And then a defined number of these patients need laser vision correction to enhance their distance vision. If they’re not 20/20, they’re gonna complain that they’re not gonna be able to see things how they like. Road signs, highway signs, names and numbers on jerseys on TV.

How successful are we? For my monofocal bilateral distance patients, what percent want glasses for better vision? I would say this is at least 30%. Just a little bit of astigmatism will lead to those problems, as I just mentioned, as far as those vision things in our activities of daily living that they’re having difficulties with.

So what about targeting and planning surgery? All the speakers have walked through this. All the different tools they use to get the best results.

And not uncommonly, it’s multiples of these. So it’s multiple ways of measuring the cornea. Be it auto-Ks, manual Ks, IOLMaster, and then axial length. Are we measuring it by IOLMaster, Pentacam, immersion?

And are there multiple formulas we might use? So one of my partners, historically, has done five different keratometry readings. At some point, you have to pick up which one is the most accurate. I find that a little bit perplexing.

That you have so many variables in this equation, trying to pick out: Which one is the best? What’s the best formula? So it really adds a lot to the decision making in selecting the lens that you’re hoping will get the person to the target refraction.

So how does the light adjustable lens work? Well… In effect, you’re gonna put the lens in. And at some point, postoperatively, we’re gonna either add or subtract power from the optic. We can do this by creating plus or minus 2 diopters of spherical correction change and up to 2.5 diopters of astigmatic change for those patients in refraction.

I will also say this number is going to go up and the company is going to have a base toric lens — maybe some time in the year 2024, where you can start with 2, and then you can adjust an additional 2.5. So we can probably get up to about 4.5, maybe 5 diopters of correction for some of those patients that will need the higher corrections.

At present, with the 2.5 diopters, I only put in 5 toric IOLs in the last year. Because all the other patients I saw I could correct their astigmatism with the light adjustable lens. So it’s a smaller number. But there are some patients that will certainly benefit from the… Hopefully soon to be available technology from RxSight. So what does the lens look like?

It’s a foldable 3 piece silicone material, the power range is from 4 to 10 diopters in power. We’re gonna implant the lens like any other typical patient, in surgery, and go back and make a calculation of how to adjust that patient. What is the process and how does that work? The lens itself is the following. Essentially three elements within the lens. There’s a polymer matrix, which you see here in green.

Free-floating macromers that disperse within the lens, and these blue dots are photoinitiators. The bottom line — as these are freely movable, the macromers, it can change the three-dimensional shape of the lens.

And we’re gonna see how that works in the next slide. So effectively, what you do is when we’re adjusting the refractive power, we’re going to place light over the lens. And we may do this asymmetrically.

We may decide we want to put more light in the center of the lens. This will cause some photopolymerization. In the central lens. And this will allow these free-floating macromers in the pink to migrate to the center of the lens.

As they do, they will increase the radius of curvature of the lens, decrease the radius of curvature of the lens to correct hyperopia. We can do the reverse if we want to correct myopia. So where we want the patient to be as far as power, we can then lock that power into the lens and keep that refraction stable long-term.

So this is adding power to the lens. I’ve kind of at least discussed this in the last slide. But let’s go through it again. If we concentrate the light or photons in the center of the lens, it’s gonna cause migration of the free macromers within the lens to the center of the lens, decreasing the radius of curvature, treating hyperopia, and getting the patient to a plano sphere refraction.

On the opposite, if the patient is myopic, we need to flatten the center of the lens. We’re gonna put light out in the periphery of the implant. Gonna cause migration of the free macromers to the periphery.

Flatten the center of the lens, lock it in place, take a person from a myopic refraction, more towards zero or plano. If they have astigmatism, we’re gonna do this asymmetrically across the major meridia.

So the LAL procedure essentially occurs — what we see in slide right. We have the light delivery device, contact lens to fixate to the cornea, and this is what the surgeon is gonna be looking at. With behind, they’re gonna see the outline of the lens. Patients will undergo conventional cataract surgery.

No sooner than 17 days post-op, after the second eye is implanted, the patient will be refracted, dilated, and submitted to the light delivery device. They’re gonna see blue light.

The treatments last anywhere from 40 seconds to 150 seconds, time for the patient. That is per-eye. We typically will do both eyes, same day. The average patient is the following. A single adjustment. Day 17.

Locking in the patient at day 21. And have them back three or four days later, day 24 for the second lock-in, and they’re finalized. About 50% of the patients need more than one adjustment. So they may go out to day 27. Adjustment on day 17, adjustment on day 21, lock-in on day 24, and final lock-in, second lock-in, on day 27, 28. They’re done.

These can be extended. They don’t have to be definitive on those times. We’ve had patients, for example, that had laser correction that had incisional keratotomy, radial keratotomy. We may not start adjustments until 8 weeks out, to make sure the cornea is stable condition, where we start basing our treatment on what we think is the stable long-term refraction.

This is what the patient is gonna see. The ring light. They’re gonna fixate on the green fixation light. We’ll place the contact lens. And the surgeon is gonna see the following. You don’t see the outline of the lens behind this. But the surgeon is gonna be looking at this reticle. Lining it up with the periphery of the lens, 360 degrees, at the time.

What do I consider? Kind of moving ahead. I think that the light adjustable lens is essentially an ophthalmic eraser. Whatever you do on your pre-op, let’s say your biometry is off or heaven forbid… You don’t have the exact power lens you need.

This allows us to basically look beyond all the variables that you have to work with, with biometry, keratometry, getting the surface just right. That we can come back with the light delivery device, and do true fine tuning of the refraction.

And it really boils down to the following. That if you’re not on power and the patient is not happy, what do you do? We’ve talked about a few of these already.

Talking about… Do you do an arcuate incision? Additional laser vision correction? LRI, lens exchange? With the light delivery device, we basically can avoid all that. It’s what I call the easy button. We just bypass all those questions and come to the adjustment of the lens with whatever power is left.

After they’ve had implantation in the light adjustable lens. So these are crazy cases. In the past, I might try to give a patient expectations that they might be spectacle-free after they’ve had incisional keratotomy. I did this early in my career. But about probably…

Oh, maybe 10, 12 years ago, I finally said… I give up. Any patient that’s had incisional keratotomy, I would just tell them: You will be in glasses for everything. Distance, intermediate, near. That changed five years ago with the light adjustable lens. I started becoming comfortable and we treat these patients with the light adjustable lens. In the past, no. But now we’re back to… This is really an easy button.

As I mentioned earlier, we do wait approximately 8 weeks for the corneas to get stable before we do the adjustment in the refraction for these patients. What about difference in outcomes? There are two slides I want to show, at least comparing a toric implant compared to the light adjustable lens implant.

As the previous speakers are talking about, you have to get the most accurate measurements possible, as far as what is the astigmatism on the cornea, select the lens, and hope you land on target.

Well, this is data from Alcon. Looking at: What percent of patients get to 20/20? This is about 38% of patients with AcrySof lenses got to 20/20 versus 86% with the light adjustable lens.

Now we’re at 86% seeing 20/20 or better after adjustment. Again, we’re treating anywhere from… Let me take a step back. The laser will adjust 0.5 diopters of astigmatism at a minimum. And again, we’re gonna maximally treat probably 2.5 diopters of astigmatism.

So toric IOLs — we know that at least 30% of eyes have 1 diopter or more of corneal astigmatism. So again, as Dagny and Jerry talked about, they’re gonna attack 0.75. Or 1. Or certainly more.

But what do we do with those people that have less than? That was kind of part of Dagny’s talk. I feel totally comfortable with the light adjustable lens, going after those. We know that you have to treat that half a diopter. You have to get the patients under 0.5 diopter for them to not have complaints.

As Dr. Vasavada said, as far as quality of vision and contrast sensitivity. So I think it really is important to treat the astigmatism, as everybody has mentioned, and get it as low as possible. I just know that the accuracy we have with the light adjustable lens is better than I have with torics.

And thus the reason I tend to default to the light adjustable lens for any-patient that I have concerns with astigmatism being an issue for them. Affecting their best unaided vision postoperatively.

Bioptics. This is essentially my last slide. Talking about: What in the world is this? Well, with Bioptics, we’re using both the cornea and the intraocular lens to correct refractive error. There’s only a couple select places where I use it, at this point.

In the past, when we were doing — let’s say the Star ICL or intraocular contact lens, in the US, we only were able to treat sphere. So if patients came in with astigmatism, we would debulk the myopia with the ICL and come back with laser vision correction to correct any residual astigmatism.

This is probably the best early example. Now with large ametropia, sometimes we have to adjust with the IOL. LAL. And we see this with incredibly large ametropias and astigmatism, we may put in a posterior monofocal or toric IOL, and then put the light adjustable lens in front of that.

And if by any chance there’s residual astigmatism, you can come back on the cornea with laser vision correction to remedy any residual refractive error.

Again, that being astigmatism or even small spherical error levels. So this is my question for everybody. And we’ll get an answer. The light adjustable lens is: A, a phakic intraocular lens, B, accurately corrects sphere and astigmatism, C, the optic is made of hydrophobic acrylic material, or D, does not have to be locked in after implantation.

I’ll let the poll be run.

And so what we have here is that… Which is correct, B. The light adjustable lens accurately corrects sphere and astigmatism.

That is the end of my talk. Bala, I don’t know if there are any other questions from the audience. I’m more than happy to answer.

DR AMBATI: Yes. There’s quite a few questions. I think you have a very popular presentation, John. Thank you for joining.

Over the years, will the LAL change power or astigmatism after contact with sunlight?

DR DOANE: So there are two… The original version that we had in the US — there were some patients that did change. You know, I’ll try to explain that.

We would do the adjustment. They would be locked in. Absolutely perfect. I might see them a month after their adjustment. Everything just spot on. Plano sphere, loving life. They might come back at three months later, and all of a sudden — wait a second!

Now they’re at -75. 0.75 at 20/30. So we did have some people that, let’s say, it wasn’t long-term. Was actually within 3 or 4 months after treatment. They did migrate. About 3 years ago, RxSight came out with a version of a lens called ActivShield.

That was part 1. The ActivShield blocked out any external UV light that could possibly change the power of the lens before lock-in. In addition to ActivShield coming about — really from a safety standpoint — the lock-ins changed. Much more robust. Since that time, I have not seen people migrate.

So we’ve had three years of ActivShield plus a very… A robust lock-in period. I have not seen migration since that time. That being said, I learned a long time ago: Never say 0% or 100% in medicine. There may be patients at some point that they could get a year or two out and say… Gee whiz. They’re off a little bit. We need to do something.

I think that’s gonna be very uncommon going forward, based on what I just said and the changes that RxSight made. So yes, things can change. And we know that certain people over time, with gravity, with blinking, may go from a certain amount of with the rule astigmatism to less with the rule astigmatism.

Or go from plano sphere to against the rule astigmatism. Or more against the rule astigmatism. So I would never rule that out over the course of decades from that standpoint. In my mind, that would not be an IOL issue. That’s more of a corneal issue.

DR AMBATI: Indeed. Patients did have some drift in against the rule astigmatism over the course of their life. Some more LAL questions. Can we modify spherical aberration with the LAL? And what size incision do you use with the LAL?

DR DOANE: Yes. I think we’re kind of… We’re probably past the first inning, to use a baseball comparison. You know, nine innings in the baseball game. We’re probably in the second inning. There are many different things we can do with the light adjustable lens.

I think the next thing, as I mentioned, adding a base toric, so we can increase the amount of astigmatism we can treat, we can… Since we project blue light on the lens, you literally can do anything you want. You can add EDOF, you can add let’s say a bull’s eye in the center of the lens to get greater near vision. You can…

If you wanted to do something customized as far as a wavefront pattern, I think that’s all possible. RxSight have done certain things that they have not released. And I’m sure their research team has all different things they could do. Now, getting out of the first few innings is obviously treating sphere, it’s treating regular astigmatism, and they’re doing a great job.

Not just adding to the astigmatism pattern. So I think that the sky is the limit. And we’re just kind of scratching the surface, as they say, of what the technology possibilities are.

DR AMBATI: What’s your current strategy as far as optimizing EDOF, extended depth of focus, with the LAL?

DR DOANE: I didn’t have time to get into too much depth. There are two lenses available from RxSight right now. There’s the base lens, that has about 0.75 diopters of EDOF, with the adjustment.

There is a second lens called the LAL Plus Lens, that comes with about 0.5 to 0.62 diopters of built-in EDOF. So I kind of alluded to this at the beginning.

That in the near eye, we don’t have to be a -2 refraction to get J1. Many of these patients could be -0.75 or -1, and be J1. Yet they’re 20/30. Maybe even 20/25 at distance. So they have legal driving vision, but incredibly good near vision. So probably 90% of the patients we treat will have one eye distance…

Let me take that back. Almost every patient we treat has some level of minus power in their non-dominant eye. With that being said, 95% or 20/20 at distance, and probably 95% or thereabouts are J1 for reading.

There will be some people that want to be a little bit sharper. They can always put on reading glasses. But we effectively have gotten to spectacle independence for the vast majority of patients.

And not having the anisometropic effects of true monovision where one eye is plano and one eye is -2 or so.

DR AMBATI: Do you use the LAL to rescue patients who have had bad experiences with multifocals in the past?

DR DOANE: Absolutely. I probably… I would say every month, there’s probably two or three patients coming from elsewhere. So I just looked at somebody last year. I think I did three multifocal lenses. And the reason I did those… One person… I had done a multifocal on the Panoptix four years ago. The second person was effectively one eyed and wanted both eyes… Correction needed…

Effectively one eye. So needed that eye to see all focal points. Other than that, I essentially do the light adjustable lens, and we see a lot of patients who cannot tolerate multifocality, the quality of vision. So we will exchange and they’ll do really well. With our scenario… Again, we have to tell them that you’re not gonna get three focal points out of one eye.

You’re gonna get two plus. Some people get three. But expect two. With two eyes working, you should get all three.

DR AMBATI: Are you using LAL in both myopic and hyperopic post-LASIK patients?

DR DOANE: Absolutely. The company line is to use the straight LAL in the hyperopic patients and not use the LAL plus. Increasing EDOF. I have used it in those patients and I can’t tell that they have any negative impact.

So absolutely. I use it… It really is my go-to lens for all patients. But it’s an absolute game changer for anybody post-laser vision correction. Anybody that’s has — liked monovision in the past. Anybody that’s had incisional keratometry and wants to be relatively spectacle-free.

And just the standard patient that wants to not be in glasses. Is just in my mind just a godsend. Again, as I talk about it, it’s kind of our magic eraser. It resolves all those issues that can affect a person’s satisfaction or happiness with their unaided vision.

DR AMBATI: Terrific. Thank you so much. I appreciate your overview on the LAL. Thank you.

The last presentation will be from me. And I’m going to share my slides.

I appreciate the audience staying in this webinar. My talk is on managing astigmatism with complex corneal situations. And…

I’ll start it here. So the challenge of corneal irregularity is that we have difficult intraocular lens calculations. That being said, patients who had prior corneal disease — keratoconus or prior corneal surgery, such as radial keratotomy — they’re long suffering patients.

So they tend to be very grateful for any improvement in quality of vision. So it’s both a challenge and an opportunity. So I’m gonna share a couple of cases. One patient had keratoconus when he presented for his cataracts.

And you can see on the topography — this inferior steepening. A lot of asymmetry on the cornea. As well as posterior elevation. And this was on the 2 months after treatment with Intacs.

So you can see that the amount of corneal asymmetry and steepening was reduced by placement of an intracorneal ring segment in the inferotemporal cornea.

Similarly with the left eye, which was worse, the keratoconus was steeper, I also placed an Intacs, and we were able to dramatically decrease the surgery asymmetry and the corneal steepening.

So my approach here was to treat each eye with Intacs. And then once the cornea had stabilized, to put in a Trulign lens. The Trulign is a Crystalens platform. It has hinges that allow it to move. It’s a zero spherical aberration. And once the cornea was normalized by Intacs, I was able to treat the residual astigmatism with the Trulign IOL.

So the outcomes… With a staged procedure, we were able to dramatically decrease the asymmetry on each eye. With the initial surgery of Intacs. And then after the second procedure, removing the cataract and placing a Trulign IOL, we were able to achieve a very nice outcome for this patient.

Second patient that I want to discuss is somebody who had prior multiple corneal procedures. Back in the ’80s, they initially had ALK, radial keratotomy, arcuate incisions. So a lot of prior corneal surgery.

And I’m gonna initially start with some general pearls that I use on post-RK management. I think it’s very important to use topography/tomography to carefully analyze the central zone of the cornea and adjust your scale to really see if you can find a regular astigmatism there.

Bring patients back at the middle of their waking day. So I ask my post-RK patients — when do you wake up? When do you go to bed? I bring them back and schedule their appointment to check the middle of their waking day.

Be aware of what your limitations are in the US. The monofocal lenses can correct up to 4.1 diopters, the multifocals up to 2.6 diopters, and Trulign goes up to about 1.8. I’m generally not gonna do a Panoptix lens in more than 4 or 6 cut RK. And realistically, with the field going the way it is, multifocals in this population are gonna be less and less common.

The LAL is probably going to take over the management of post-RK patients looking for depth of focus.

It’s important to have piggyback lenses, PRK, and ocular surface optimization in your toolkit to manage the postoperative course of these patients.

Lastly, axial length can affect toric effectivity. In long eyes, you may not get as much toric correction as you expect with the toric IOL. So this patient who I just described, who has had ALK, RK, and arcuate keratotomy, she presented to me with 8 diopters of astigmatism.

Against the rule. You can see this beautiful blue vertical bow tie. She had 8.25 diopters by corneal Scheimpflug imaging. Slightly long axial length. The optical biometry measured 9 diopters. So she had a lot of regular corneal astigmatism.

So what I did for this patient was plan her surgery with Barrett True K. And I used 2 toric IOLs. So I placed one in the bag. And one above it in the sulcus. I split the toric power 50/50.

Each IOL had corrected about 4 diopters of astigmatism. I used a 6 diopter sphere for piggyback. That was the thinnest. To place in the sulcus. And we used a CTR to improve the IOL centration and rotational stability.

So I placed a Tecnis toric as well as M860VT. This has eyelets that allow rotation, which is much more convenient. And this is the post-op image. You can see both lenses on top of each other.

Conceptually, there’s the primary IOL in bag, piggyback IOL, also a toric, with the optics in the bag and the haptics above the anterior capsule. She did have some residual astigmatism, which I treated with PRK.

And six months later, she was 20/25, +2. So in conclusion… In other parts of the world, where there are silicone plate IOLs, you can do double silicone lenses in the bag.

In the US, there are no silicone toric IOLs. So this patient — we used a piggyback toric IOL on top of a primary toric. In other parts of the world, there are customizable IOLs that go up to 12 diopters.

But those are not available in the US. But this offers another option for patients with extreme astigmatism. Where we can have a toric IOL in the bag.

And piggyback toric on top of it. So I’ll end with the video, basically. The initial lens was the Tecnis toric, going into the bag. And then on top of that, we put a piggyback toric, and we’re lining up the marks on both.

So that they’re lined up. And we use an Ahmed micrograsper to achieve that final optic capture. Where the optic is above the anterior capsule and the haptics remain in the bag.

The micrograsper can hold the lens, while a Kuglen is used to move that superior optic edge anterior to the rhexis. And achieve the optic capture.

So then align everything. Make sure that both lenses are in perfect position. And the lenses are well centered. Here you can see the optic capture with the anterior capsule between the lenses.

And then the marks of the primary IOL and the piggyback. So with that… I will end with a question.

Which of the following of contraindications to astigmatism correction in cataract patients? RK, Fuchs dystrophy, Salzmann’s nodules, epithelial basement membrane dystrophy, or none of the above. They can all be managed/optimized prior it cataract surgery. Please answer at your convenience and we’ll see the results momentarily.

And indeed the plurality said none of the above. What I would like to leave the audience with is that corneal disease should not scare you off from astigmatism correction. We can manage any of these conditions.

Fuchs dystrophy with DMEK, Salzmann’s with removal, epithelial basement membrane corneal dystrophy with PTK or superficial keratectomy, and all of these corneal challenges can be overcome to set the stage for correction with astigmatism correction.

So that’s it for me. I’ll go back to the Q and A.

Do I have any experience with LAL and keratoconus cases? John. I don’t know if you’re still there. If not… I will post the question… Hey, John. You are there. Terrific.

Do you have experience with LAL and keratoconus cases?

DR DOANE: Absolutely. So we’ve had to do some effectively piggybacks. So some of these patients — I give a couple of examples just in the last two weeks. I’ve had two different patients that I had to put in minus powered IOLs posteriorly.

And put the light adjustable lens in front of it. Because the keratometry is so high that effectively you would need a single minus powered IOL.

So one of the patients, the posterior lens was a -10, J and J, AR40 series lens, the other one, the posterior power lens was a -8. The anterior lens was the lowest powered light adjustable lens available.

It was a +4. Now… Neither one of these patients I’ve adjusted yet, because they’re not at the 17-day time period. So we will come back and adjust them to wherever they need to be. The caveat is: Do they have irregular corneal astigmatism that may limit their best uncorrected vision?

In this case, they both surprisingly still had good uncorrected vision. So I’m hoping that at a minimum, they would refract to 20/20. And I’m hoping uncorrected-wise, we can get them to 20/20. So in the past, I think this would have been very hard to do. You can still use the keratoconus IOL calculation formulas. And you obviously have to do some summation between the powers of the two eyes.

To try to get roughly to plano. And adjust one way or another, if you’re off. So absolutely it can be done. I talked to RxSight, and they’re hoping, as I mentioned earlier, the range of the light adjustable lenses, +4 to +30… But they do think that they can have a minus powered lens.

So maybe we could do these with the single lens, at some point in the future.

DR AMBATI: Terrific. When you’re doing the LAL as a piggyback, are you putting the LAL optic in the sulcus? Or are you putting it in the bag?

DR DOANE: Great question. I put both lenses in the bag. So there’s an acrylic posterior, silicone anterior, but both bags, all haptics, in the bag.

DR AMBATI: Gotcha. So next question from the audience. I’ll pose it to both Dr. Vasavada, and Dr. Doane.

What are your experiences with the IC-8 Apthera?

DR DOANE: I haven’t used it, but (inaudible) — I can’t imagine it wouldn’t be helpful. Dr. Vasavada?

DR VASAVADA: Likewise. I don’t have access to it yet. So I can’t say much. But it does look very promising in a lot of these irregular corneas. The only problem being a lot of these post-RK eyes are also high myopic eyes. So with the retinal evaluation, we just need to be a little careful with all of these devices.

DR DOANE: Yeah, the only other option we have to neutralize the irregular corneal astigmatism that would push a person into needing a rigid contact lens would be to do a deep anterior lamellar keratoplasty. That would be an option to help resolve.

As an alternative option.

DR AMBATI: Yeah. Very aberrated cornea — just start over with a new surface. Question for both of you. What are your recommendations if you’re planning a toric lens and you have a posterior capsular rupture or anterior capsular tear? What would you do?

DR DOANE: At least for me, doing the light adjustable lens, you can still put — it’s a three piece lens. So you can still put that lens in the bag. Or… And you can also, you can put the lens, the haptics in the sulcus, and capture with the anterior capsule.

So you’re not out of the woods with the light adjustable lens. You can still use it in those cases where you might not be able to use a one-piece acrylic lens.

DR VASAVADA: Yeah. I think… I haven’t used the LAL. I don’t have access again. So if it’s an anterior capsular rupture that does not extend beyond the equator, with these hydrophobic acrylic toric IOLs, I can still manage to put them in. Be very careful, like Dr. Zhu mentioned, before the haptics open up, put them in position, very gently guiding.

So I have done a couple of cases, and the lenses remain very stable. If it’s a posterior capsular rupture and it’s a small one, I would convert it into a posterior rhexis. Do a vitrectomy. And then put the lens in the bag. But if it’s large, then I think… It’s better to go for a traditional monofocal.

DR AMBATI: Bala, one other thing too is — I’ve done… I think I’ve got four or five patients that I’ve done the Yamane technique with the LAL. So it can be used in that role as well. Which is really slick.

DR AMBATI: Terrific.

These challenging situations, where you have a capsular tear, I think you really have to individualize the management of the patient. If you have a small anterior capsular tear, one thing I do is sometimes I’ll do two or three other relaxing

So that the tear doesn’t extend. And then if you have a posterior capsular tear, as Dr. Vasavada mentioned, you can do a posterior capsulorrhexis. And/or you can place the haptics in the bag and the optic above the anterior capsule.

So there are a couple of different approaches you can try. Last question. We’re at the very end. Last question. I’ll pose this to Dr. Doane. This is from an ophthalmologist, I believe, in the Middle East.

Why has the LAL not gained popularity? Only a few doctors are using it even in the US.

DR DOANE: That’s not the case at all. In the US, there are literally hundreds of doctors using the light adjustable lens. I think they need to get their feet grounded well in the US and start moving ex-US. Which I think they’ll do. I’m trying to remember the number.

I want to say there’s probably… Gosh. I could be way under, if I said there were 400 doctors that were certified to do it in the US. It’s growing tremendously. At last count, I think they had about… Maybe 100,000 implants in the US?

So… It’s growing dramatically.

DR AMBATI: Well, thank you all.

I would like to thank Andrew Chen and Lawrence Sica from Cybersight for arranging this, and all my fellow panelists. Dr. Doane, Vasavada, Hu, and Zhu. And have a wonderful day, everyone.

Have a wonderful week. Thank you.

Last Updated: July 2, 2024

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