An Extended-Range-of-Vision IOL
Gary Wörtz, MD:
Open. Outspoken. It's Ophthalmology off the Grid. An honest look at controversial topics in the field. I'm Gary Wörtz.
This past summer, US surgeons gained access to a technology many have long coveted from abroad. The Tecnis Symfony IOL from Abbott Medical Optics adds a new device to the cataracts surgeons' armamentarium and represents a promising solution for patients seeking a high degree of spectacle independence without compromising their near vision. Today, we'll hear from Dr. Kevin Waltz about his journey with the Symfony IOL, which began with the first clinical trial in Honduras in 2012. Kevin shares with us how that experience paved the way for the technology's warm welcome into clinical practice back home.
Kevin Waltz, MD: AMO will tell you that that process shaved between 18 and 20 months off worldwide delivery of the Symfony from AMO. Had we not done that, if they had followed the original plan in Germany, nobody in the world at the moment would have Symfony.
Gary: In addition, we'll hear from Dr. Jason Jones on his experience with the Symfony, including pearls for the use of this lens and real-world perspectives and where it will fit in going forward.
Jason Jones, MD: I really backed away from a lot of multifocality in my practice; I went more towards monovision. As I was at the same time seeing this new development of this technology with the Symfony lens, I started to feel more confident that this may be a pathway for us to find a more acceptable quality of vision and still have a high degree of independence from glasses.
Gary: Coming to you now, on Ophthalmology off the Grid.
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Well, today we have Kevin Waltz with us, and Kevin has been a friend of mine for a while. Someone that has helped in my own lens venture, someone who I really trust—all things lenses and all things cataracts surgery. It's really a delight and pleasure to talk to you today, Kevin. We're going to be talking about the Symfony lens, a lens that you had your hand in from the very beginning. Give us a little bit of your thoughts on this technology: your first impressions and how you saw it develop and maybe when you started becoming a true believer.
Thanks, Gary. The Symfony lens for me has been an interesting journey in part because I had the privilege of doing the first clinical trial with the Symfony in Honduras in 2012. One of the things that's important to know about the Symfony is that the trial wasn't just a one-off one lens trial. AMO actually had done a phase trial with three different lens designs in an attempt to get the best possible distance vision, with the least amount of unwanted visual sensations at distance, glare, halos, etc. At the same time providing useful near vision. You can imagine that's a tall challenge, and it required human input. You can't just do that in the lab.
You can theorize how well it's going to work, but in the end you had to do it in humans. There's only so many places where you can do that and you can do it in a reasonable time fashion. The 50% of those sequential trials were done in Honduras, the last was in September, October, November of 2012. We compared the Symfony to the ZCB00, and it was really amazing because it worked exceptionally well. Even then, that particular design was what the Symfony ultimately became. It was also quite ironic that we had these patients in Honduras that normally couldn't afford cataract surgery. That had a very interesting lens that you couldn't buy for any price anywhere in the world.
Isn't that interesting. You're going down and doing a human trial with technology that we're now using, and you're exactly right. You're giving absolutely maybe the best premium lens available nowhere else to this population. Now you've got people with just incredible range of vision that otherwise may not even have access to cataract surgery. To me, Kevin, that is like the ultimate win. You're doing a good thing, you're helping people who may otherwise not be able to get care, at the same time you're making a contribution to a company that has deeply invested in research. Also, the field of ophthalmology where we're seeking to improve the technology we can offer patients.
Our conversations have ranged from mission work in the past to what lenses are you using but it really seems like this is a sweet spot for you. Giving back, doing charitable work, but at the same time pushing the envelope forward with innovation. Talk to me a little bit about that journey. Maybe we'll come back to talking more about the Symfony and where it's at in your clinical practice.
Well one of the things that's wonderful about Central America is that in spite of the reputation, the regulatory system there in most countries is actually workable. It turns out that in Honduras and El Salvador, it's very workable. The way that AMO started the process with Symfony is the first trial was done in Germany with three different sites. The enrollment took a year and a half. By the time you did the enrollment, the data analysis prepared around 2 years into it. They did the second, the first half of the second round was done in Germany as well.
They're a year into it, and they're going, "Holy cow, this is going to take us a decade to get this done." I had done some work for AMO previously in Honduras. I actually did the ... we had a custom modified interlace that we did femto capsulotomies with in Honduras. It was the only time that it was ever done in humans with an interface. It worked quite well, and some other things and of course had done research for them in the US and they said, "Look we've got to speed up this process, can you help us?" What was amazing was that they had ... 15 patients was our comparison point because they had the 15 patients done in Germany.
We did 15 bilateral patients in Honduras, and we could compare 15 to 15, three good sites in Germany to our site in Honduras. From go, which was about the middle of January of 2012 this was round two, we identified patients enrolled and completed surgery before the end of February. So, we did it 6 weeks. We got IRB approval, protocol approval, and identified patients, and completed surgery in 6 weeks.
Gary: Wow! That's lightning fast.
The challenge, of course, is then you have to have really good follow-up. So, we send down my research technician from the US to do the 1-month and 3-month follow-ups, which were quite difficult. They were 3-hour exams plus for each patient. At the end of that, AMO had the data, they were able to show that we got equivalent results to the German site, and so they said, "You can have round three." In round three, we did the same, from beginning to end of the study ... well beginning to completion of surgery enrollment was about 6 weeks. We did 30 bilateral cases.
AMO will tell you that that process shaved between 18 and 20 months off worldwide delivery of the Symfony from AMO. Had we not done that, if they'd followed the original plan in Germany, nobody in the world at the moment would have Symfony.
Kevin: It was very satisfying for our team to be able to contribute in that way and then to have it work so well was additionally satisfying, so it's been quite amazing in the process.
That is incredible. In my experience, I've done about at this point 10 to 12 Symfony lenses, so still kind of early in the experience, but it's a different lens. I think a lot of folks have thought about this as the next multifocal or just another multifocal or another low-add multifocal. To be honest, my experience with the low-add multifocal from Tecnis was tremendous, and so there's nothing wrong with those lenses. Just like any other multifocal, you really just have to be spot on with your biometry, and you have to make sure that you're picking the right lens. Just not quite as forgiving perhaps as a monofocal lens.
Even with regard to leaving a little bit of uncorrected astigmatism or the times where you have those surprise post astigmatism that you're not counting on. There are just some nuances to multifocal lenses that we all have learned to deal with and can deal with. With these patients I'm using the Symfony on, it really seems like there's a much larger sweet spot. It really seems like that's by design. As I've talked to some other folks it seems like there's about 2.00 D of a visual plateau. If you can land the plane anywhere on that visual plateau, you're going to have good distance vision.
Depending on where you end up on that plateau of vision will really determine how much near vision you have. What are your thoughts on this lens versus the other lenses in this market of the presbyopia-correcting technologies?
Well, I agree with your comments, Gary; I think that those are pretty accurate. The challenge we have with the Symfony is there was quite naturally a lot of emotional and psychological buildup to it. One thing that's characteristic about ophthalmologists, myself included, the thing that we like the most is that which we cannot have. Since we couldn't have the Symfony for so long, we coveted it and coveted it, and we made it solve all of our problems, which it won't do, but it will solve some of them. The ones that it will solve pretty reliably, which you just described, if you have a multifocal lens, even a very high-quality one like the low-add Tecnis multifocals.
You really need to be plus or minus 0.50 D on your cylinder, and you really need to be plus or minus 0.50 D in sphere. That's in today's world the best surgeon in the world cannot do that every time. I've published my results, and typically I'm 8/9% doing laser vision correction enhancement to get everybody right. Then when you do that they're spectacular, but it's more hustle. The Symfony will decrease those enhancement rates.
You'll be able to tolerate a little bit more unexpected astigmatism, depending on what exactly they want for their near vision. You'll be able to tolerate a little bit less precision on your distance. Now, you can't be off on your sphere and off on your cylinder and expect all that forgiveness. It'd be better to be off just in your sphere or just in your cylinder to get the maximum benefit out of the Symfony. The other thing that it does is it will help you with irregularities. If you've got irregular astigmatism, it'll be a little more forgiving of that. We don't have good FDA data on that, but I can tell you from personal experience that that's the case.
How much? We don't know, we're not able to say, but certainly it's more tolerant than a multifocal in that regard.
Gary: Right. Then you throw in on top of that the fact that we've got a toric version. That adds a whole another element to what this lens can do for us.
Absolutely. That actually has been probably the biggest change for me. In the past, we all had this artificial divide that about a third of the patients of the population have enough astigmatism, you really don't want to use a multifocal. You're going to treat them with a toric. And then the other 66% or so, you can do a multifocal if you want. You've got this artificial divide. Now, all of a sudden, you don't have that artificial divide. At what point do you start treating astigmatism? For me, I've treated it at even a lower point even though the Symfony is more forgiving.
If I've got say 0.75 D predicted astigmatism postop, I'm still going to put in a Symfony Toric because the patient will be better off if I treat that 0.75 D of astigmatism. It'll give me more leeway, more flex in my sphere. I can be off a little bit more in my sphere if I do a little bit better job on my cylinder. Let me give you some metrics to help understand the relative value of it. With the Tecnis multifocal platform, we looked at this retrospectively from the FDA data, and if you're plus or minus 0.50 D in cylinder, it pretty much doesn't matter how much cylinder you've got.
If you add 0.75 D of cylinder, so from 0.50 to 0.75, you lost a line. If you went to 1.00 D, you lost two, and up a 1.50 D, you lost four lines of vision. A big hit. What we were able to show with the Symfony is at a 1.50 D of residual astigmatism, you only lost one line. It's not that you didn't lose any, but you lost one-fourth of the lines that you do with the multifocal. It's not perfect, but it's certainly more forgiving. That aspect of it encourages you to treat the astigmatism more. Where before if you had a patient that say had 1.00 D of cylinder predicted, you might try to go, "Okay I'm going to treat the cylinder with an LRI or a laser incision or something."
You've got a little bit of imprecision about that if you're using a multifocal. Well, you have less imprecision if you're using a Toric Symfony, and so you tend to get a little bit better result.
Kevin, talk to me about your thoughts on maybe mixing and matching this lens with either a low-add or maybe a traditional multifocal, or even doing a mini-monovision, where maybe in the nondominant eye you're targeting -0.50, -0.75, -1.00. What are your strategies when you're approaching a patient and you know that they want to have full range of vision? Just walk me through that. You start with the dominant eye and then make adjustments on the nondominant eye, or what are your pearls and strategies?
Well, first of all Gary, let me caution everybody by saying even though I have a lot of experience with this, I don't have the ultimate answer to those questions. I can give you my current point of evolution in those answers, but then maybe 6 months or a year from now, I would change my mind.
I tend to like, when a product first comes out, to do bilateral implantation. It teaches me about the product. I also recognize it. I'm pretty good at achieving plus or minus 0.50 D, in a monofocal it's a low 90% so I don't miss too much but I still miss occasionally. I tend to aim with a Symfony for about -0.25 in both eyes. On average, I'm going to get one eye a little bit plus, one eye a little bit minus. Effectively, I get a little bit of mini-monovision, and that works quite well. That's what happened in the US trial. The investigators on average left people about -0.25.
With that, the patient was 20/20 distance, 20/20 intermediate, and 20/25 at near, 40 cm. These were the first 148 eyes across 14 sites, so early experience with a lot of investigators, very consistent visual outcomes. Most patients are quite satisfied with that, there will be some that won't. For instance I've had a patient recently who was -8.00. Had done monovision her whole life, her whole presbyopic life and said, "Look I've got to be able to see something super close, and that's the way it's got to be." In her we put Symfony in her distance eye which was a dominant eye and then the near eye I put in a ZMB00 a +4 Tecnis and aimed for -1.00, and she was thrilled.
Because that was a lot better than she had with her monovision. You can come across those occasional strange cases and creative thinking will get you the answer. As a general statement your plain vanilla patient will do beautifully with bilateral Symfony’s.
Well, and that mirrors my, again, limited experience. This is something that … it's hard to talk about a new product with any authority as you mentioned because we're all still feeling this thing out. I've had a number of patients that 20/15 distance and 20/20 intermediate J1, J1 plus near, and that actually blew my expectations away. I did not expect them to get quite as good near vision as they're achieving. That may not be every patient but we're targeting between -0.25 and -0.50. Based on the defocus curve, it really seems like if you're able to do that, you're going to push a little bit more near vision without giving up so much in the distance.
I've not had any patient so far, again low numbers and we can talk in 6 months and have a different conversation perhaps, but so far I've really not had any patients that were anything but thrilled with their quality of vision and range of vision. I actually had a patient the other day who, in between surgeries, the Symfony was approved so we had done her first eye with a monofocal lens. She had heard the messaging about the Symfony and wanted the Symfony in her other eye. She was so thrilled with her vision in the second eye she actually wanted me to explant her first monofocal lens and put a Symfony in.
Now, we had a conversation about that, and she ultimately decided to not do that because she was doing pretty well. It just goes to show this is a different lens from maybe anything I've ever experienced before. I've never had a patient previously who wanted a monofocal lens exchanged for a multifocal when they had both to compare. I think that speaks volumes to not only the range but also the quality of vision, which that's what we've been all looking for for quite some time.
Yeah, totally agree, Gary. Here's an interesting commentary on the forgiveness of the lens. I was involved in the original Tecnis multifocal trial and the subsequent low-add Tecnis multifocal trial, the Tecnis Toric. All these are special lenses, and the patients are quite demanding. One of the things that I do as a courtesy to patients is after the trial is over and our gloves are off, if there's an occasional patient that's not quite satisfied, I'll go back as a courtesy and just do laser vision correction to make their vision good. That's happened in virtually every trial I've ever been in because it's your first experience. You're not going to get it just right. You're going to have issues.
Kevin: The first trial that didn't happen in was the Symfony.
At the end of the Symfony trial, nobody wanted laser vision correction, not a single person. It was no charge, no hustle. They said, "Doc I'm fine, leave me alone."
Gary: What was the number of patients you're talking about here?
Kevin: I think kind of in the 20s.
Okay, but still from a first experience, that is pretty incredible, and I think that is an interesting commentary when that's been your first lens that that's not happened with. That is very interesting.
You've got good anecdotal evidence that it's going to be forgiving. The one thing that has surprised us, the investigators, after FDA approval is the range of symptoms in the patients after FDA approval was different than the range of symptoms of patients in the FDA study. I was very interested in what the symptoms were going to be in the study, and I personally talked to most of the patients and basically you couldn't get any adverse symptoms out of them. You'd ask them, "How are you doing?" "Fine." "Are you seeing halos?" "No." "Are you seeing glare?" "No." They just didn't have much to say other than “Thank you very much.”
Then, after FDA approval, we've been surprised there's been more symptoms than I would have expected, and we think it's probably related to just big payments, and that changes your expectations.
Gary: If you're in the trial and you get it for free, your expectation level is a little bit lower and your willingness to perhaps tolerate some of these things is higher.
Kevin: Yeah, and I'm not even sure tolerate ... patients just didn't see it.
Now, if you look at the FDA results, there were quite a bit of directed questions, meaning we had an independent group call up the patients and ask them about it and directed questions. There was quite a response. The base lens is a ZCB00, which is known to have very few adverse symptoms, it had quite a few adverse symptoms in the trial. The Symfony didn't have that much more over the base lens. I think it was probably just how we asked the questions.
Well, and the way you design a trial and the way you're asked to design a trial ultimately determines or in some way shapes the results you're going to get. If you're just waiting for people to spontaneously complain about something, your number is going to be a lot lower than if you ask them and prompt them to analyze their vision for a certain symptom, glare, halo, etc. Even the mere suggestion of something can sometimes have that reverse placebo effect that, “Oh, I think I do see that perhaps.” We know there's no perfect lens. Every lens out there there's going to be some trade-offs. There's going to be some issues with certain patients, but I do feel like in my gut that the Symfony is raising what it delivers on.
Raising the performance with very, very minimal reduction in quality of vision or addition of glare, halo symptoms. I feel like we've really gained something here that we previously didn't have.
One thing that we can expect with the Symfony is the unwanted visual sensation profile will be a little bit different. A halo is caused because you've got two peaks of the defocus curve. You've got your distance peak and your near peak. That little dip gives you the clear zone, so the halo is a lot of light in the center and then the circle of light around it represents myopic defocus. You don't have that with the Symfony. What you've got is a little bit greater glow right around the distance image, but you do get a little bit more star busting because of some optical reasons.
In general, the Symfony doesn't have much in the way of halos, but it has a little bit more star busting. Patients will oftentimes describe it when you query them as almost a little bit of a spider web pattern. It's not particularly bright, but if you've got a dark background, you can see that. The symptomatology is slightly different with a Symfony than a multifocal. Now, it's also important to know that if you've got just a monofocal, you get significant extra sensations from that monofocal. Back in, I think it was '06, Chang published his book on premium lenses, I wrote a chapter in there on the unwanted visual sensations you get from just a plain old monofocal.
They're not insignificant. Most patients don't notice them or don't care about them, but if you look at them, they're definitely there. Those things, we expect the Symfony to have a little bit different symptom profile. The other thing that is interesting to think about is this, and I'm going to need you to release your mind just for a second, you're too young to remember this era, but back in the 90s it was very cool to use extended depth of focus with astigmatism to improve patient's results after cataract surgery. The ideal back then was plano minus one cylinder. Which was very difficult to achieve back in the early 90s with our level of biometry and calculations, etc. If you could achieve, that you could pretty reliably get 20/30 distance intermediate and near, and so that's what the cool kids did.
The difference with the Symfony is by fixing the chromatic aberration, you give so much available extra light to focus that when you extend the depth of focus, we purposely only decreased the best focus down to 20/16. If you just fix the chromatic aberration to make it a monofocal with diffractive optics, you can get to about 20/08.
Gary: Which is really beyond the resolution limit of the retina at that point.
Kevin: Yes. We drop that defocus curve and extended it out to the right, but we didn't drop it more than a theoretical 20/16, which is why you're getting such good visual results at distance.
I think that's a key point. When we're talking about a multifocal, you're talking about taking all the available light and splitting it between two different foci. That's limited by the material and the other perhaps imperfections with regard to the material you're using. What I think is interesting is it's like with this material and the correction of chromatic aberrations AMO started by increasing the amount of available light for focusing, and then flattening out that defocus curve, which really to me is the secret of all this. Would you agree?
Yes, completely. They basically created extra light to focus, and then advantageously moved it around. That's why they needed to have the human trials to be the way they were because they weren't quite sure how the human would react to it. In the first two rounds, there wasn't enough near vision, so it took the third round to get the secret sauce right.
Well, I'll tell you I'm very impressed with what AMO has done. I'm super happy to have this, another tool in my tool belt to offer patients. I'm just absolutely thrilled that we finally have another lens to offer patients with better range of vision, low side effect profile. Overall just happier doctors, happier patients, happier life. Kevin, thank you so much. Any parting thoughts before we wrap this up?
One final thing, Gary, this one's a little bit higher concept, but it's important to think about because it will allow you to use the Symfony in other ways that you might not have thought about. One of the negatives of using astigmatism to increase the depth of focus it is radially dependent. You've got two axes at 90 degrees apart. The Symfony technology, the extended depth of focus, is up to 360 degrees. If you get, let's say a four-cut RK patient, they've got quadrofoil, you're going to get different focuses, and we use that to extend their depth of focus. Well, the Symfony will automatically refocus those different foci beneficially for the patient.
Gary: Are you saying that this is a patient that has some potential applications even for the RK patients?
Kevin: Yes. Now, of course that's off-label. We haven't studied that, but I've got patients already that I've put the Symfony in with RK patients, and they love it. They recognize that all of a sudden there's more light focused at their fovea than there has been in a long time.
Gary: That is really interesting. I've already used it myself in a post-LASIK patient, and it had great results. This technology, I think, is going to extend not only the range of patients for those who've had higher levels of astigmatism but maybe even another chance to reset the deck for patients who've had laser vision correction. Now maybe even RK. That's very interesting, Kevin.
We don't know for sure that this is the case. We're starting a phase 4 study as we speak, but anecdotally we've had some very nice experiences, and we're getting ready to implant a well-known refractive cataract surgeon who has prior RK, and he's going to volunteer to be the first ophthalmologist with RK and Symfony.
Gary: Well, very good. We'd love to have a follow-up on how that went, and maybe if he's had an interesting experience he would like to come on and give us his story. Let's keep that in mind for the future.
Kevin: All right, Gary. Thanks so much.
Awesome, Kevin. Thanks for everything you've done for me personally, for our field, and for the folks in Central America. You've made a huge impact.
Another key player in the development of the Symfony IOL is Dr. Jason Jones. Jason served as a clinical investigator at one of 15 sites in the US clinical trial. I touched base with him to see what the experience was like and to collect some intel on how the lens has been performing since then.
Welcome back to Ophthalmology off the Grid, and today I have Dr. Jason Jones from Sioux City, Iowa, on the program. I'm really excited to talk to Jason because he's been involved with Symfony from the very beginning, from the FDA trial.
He's just got a lot of good information. He's got a lot of great perspectives. Jason, I read your article I believe it was just last month in CRST about your experience with Symfony. You shared a lot of pearls of wisdom, and I was wondering if you wouldn't mind just going through your experience with Symfony, giving us some real-world data, some real-world perspectives on Symfony, where you really see it fitting into our armamentarium going forward.
I was a part of the FDA study, so we had a certain number of patients we could enroll, and they were randomized one to one. That actually, even at this point, still is the bulk of my experience. I do have several implantations most recently done as well as a commercial device. My experience with the study was overwhelmingly positive. Patients really enjoyed excellent distance vision, intermediate vision. In my experience with my patients, they really had good near vision, which was a bit of a surprise. We didn't really fully expect quite as much near vision out of these devices. That was a really welcomed thing.
Patients, generally speaking, had 20/20 or better uncorrected distance vision, and one patient had even 20/10 uncorrected vision. It was just incredible level of visual acuity. Quality of vision seemed very high as well. Patients did report they had some halos, but they were not bothered by that and they did not feel it was intrusive to their vision. I did have one patient notice halos even in daytime with regular illuminations like such as in my exam room the ceiling lights when I had them on. I had to have follow up with him over time, and now more than a year out, he says he doesn't see them at all. He's extremely happy with his vision.
Patients really don't wear reading glasses that often. They do wear them for specific things like reading small prints in the back of a pill bottle, for example, or perhaps threading a needle—something very fine that may require some additional assistance with a very-low-power reader. Patients are not using 2.5 or 2 adds; they're usually using and 0.50 or even lower in terms of adding a reading glass to their use. They truly do use them rarely. Visual acuities but also just patients, my perceptions of my patients' experience, was really exciting, and I was on the edge of my seat waiting for this to get approved.
It really did go through the approval process quite quickly with the FDA, which was nice to see. Not only did we get the Symfony approved but also the Symfony Toric, which was a fantastic add to what we have available for our patients. I think, certainly as you know Gary, it's the first presbyopia-correcting toric lens in the US market, and these lenses have been deemed presbyopia-correcting by Medicare as well. I think we now have some really great tools to go forward with our patients. In my experience, I find that the past multifocal lenses had a lot of promise, but they also had a lot of problems.
As I used them a fair amount for a while in my practice, I had some disappointments, and some of them became very emotionally involving with the patients, my staff, and myself as well. I made sure to basically correct these patients. I did IOL exchanges when indicated, when it would help them, and I was impressed how well patients would recover a good feeling of quality vision with the monofocal lens. I really backed away from a lot of multifocality in my practice and went more towards monovision. As I was at the same time seeing this new development of this technology with the Symfony lens, I started to feel more confident that this may be a pathway for us to find a more acceptable quality of vision and still have a high degree of independence from glasses, certainly for those patients who have the desire to obtain that outcome. As we all know, these patients have to pay extra money for it as well. I think actually these lenses at least in my practice are largely going to supplant a lot of multifocality. I don't think multifocals are a bad thing either by the way. I still think they have their place, but I think a very frank discussion with patients in terms of where the issues are for these different lenses. Multifocal lenses may give you a larger amount of uncorrected vision both for distance and near.
However, some quality vision issues are more prominent with those lenses, and you have to be willing to accept that trade-off. Here, we've got a little bit of higher quality of vision, and reading vision for some patients is not quite as robust, at least by the reports in the FDA trial as well as in the real world with other people. People are reporting some patients see incredibly well and other patients don't have quite that same level of uncorrected near acuity. There are some modifications that people can do in terms of choosing defocus as a target for a nondominant eye, for example, with Symfony.
That is partly how I plan to move forward with using Symfony as my primary presbyopia-correcting choice for patients who are wanting good acuity balance vision between the two eyes. I think monovision will still have a place as well, by the way, so I think we have such great tools available to us. It's, I guess, really a good time to be a patient who needs cataract surgery.
Gary: Yeah, it is.
Jason: We have such great toys, if you will. We have such great effectiveness in terms of what we can actually do for these patients. It really is quite incredible, I agree.
Gary: It's a great time to be a cataract surgeon, don't you think?
Gary: Jason, you packed a lot of information in there. I'd like to just dive into a couple of those.
First of all, you're saying that your patients have had pretty good experience with near vision, and I'll tell you my end is much smaller. I think I just implanted my fifth Symfony today. A couple of those have been Symfony Torics, but the first one I implanted was a Symfony Toric. Day 1, the guy is 20/15, 20/20 intermediate, and J1 near, and that has not changed. He got his other eye taken care of. This guy is just over the moon. Second patient has done equally well, and obviously we don't always hit our targets, that's just life. That's part of being a cataract surgeon, and there's still variability. What I love about this is if you really look at the defocus curve you get ... This lens is just so forgiving because you get some forgiveness both in the hyperopic direction as well as the myopic direction.
When I was looking at the defocus curve, I was thinking to myself, "You know it really probably makes more sense to aim for almost -0.25, maybe even up to -0.50." Because the plateau effect or the extended depth of focus, it'll work backwards for you by almost 0.50 D. If you do that and you get pretty good there, you'll still have that great quality 20/20 distance vision, but you're going to have basically 20/20 vision all the way up through 2.00 D of near-sightedness. I think that's probably ... maybe you can speak to that that maybe some patients see great distance and intermediate, but maybe we miss the mark a little bit. That's why they're not seeing quite as well up close. Do you think that plays a role in how well people see up close?
I definitely do, Gary. I think it's a really important point, in terms of being able to give the best performance here with the Symfony lens. I think it really pays to do due diligence on your IOL powers, on your surgery. Pay attention to all the details. Yes, it's more forgiving, I completely agree, but the more that you do pay attention to it and get those little areas right and actually hit your target more readily, the more likely you're going to deliver that outcome that we want, both distance, intermediate, as well as near vision, as you've experienced with your own fantastic outcomes already.
I think that some experiences early on OUS that I've heard about, some surgeons have reported that it's not quite such a near vision lens. I would have to question, how do they choose their lens power? What formulas do they use? What biometry do they use? How accurate are they with their calculations? Just because you're using the right biometer and have the right calculations and all the right constants doesn't mean you actually hit your target. You need to actually dig into your own backyard, so to speak, and figure that out yourself. The other thing I know people have done is to deliver excellent distance vision and ensure that you get distance vision.
Some people will actually choose a slightly hyperopic target at least in the dominant eye. It's not a bad strategy, but, on the other hand, it takes away from the near and even some of the intermediate vision that patients can get. It really behooves us to actually do our due diligence and really titrate ourselves as much as possible in terms of those outcomes. I go through a process with these patients, which is not that different from what I do with my monofocal lenses, except I get more measurements. I get a second set of measurements. I do topography on everyone, even if they don't have a lot of cylinder.
I'll even treat a fairly low amount of cylinders, especially if it's against the rule. I'd rather leave them maybe with the rule afterwards if we have to. A toric lens is a fantastic piece of armamentarium to deliver that outcome. I think of that defocus curve as a reserve capacity or almost like a focus bank. If you target hyperopia, you're going to steal some from that defocus curve in terms of getting the broader range the patient wants to have. I think if we could actually nail down our target system and really get that fantastic fine-tuned outcome.
It's really also important to talk to patients about the fact that you may have some glare and halos. They usually do get better with time. I think it's still important still to bring up that as a possibility. I have heard that outside the US when that wasn't discussed, some patients found that they had those and they were upset. When the strategy changed in those markets to informing patients, there was a lot more happiness and acceptance of it. It's much easier to go that route, and I think it's just safer for the patient and yourself too. As well pushing plus on your refractions to make sure that you actually are getting a really good accurate outcome. One of the fantastic things about the Tecnis platform for the single-piece acrylic is that those constants for the ZCB00 really travel across to the toric monofocal.
To the Symfony, to the multifocals, to the Symfony Toric. You can become comfortable with your IOL power calculations and knowing where your targeting is just by having an experience even with monofocal lenses. You could use those as a good barometer for how accurate you really are. In my own practice, basically a lot of the same steps I do are the same for all the patients whether or not they're getting a Symfony, or they're getting a toric, or they're getting what have you, a monofocal lens. All those things really breed a better outcome, a tighter grouping. I think adding a little bit of minus in the nondominant eye, which was actually a paper presented at ASCRS from Daniel Black, that is a strategy which has a good ability to enhance near focusing for a lot of patients.
You said it really nicely that the Symfony lens is almost like a reserve power bank or a power reserve. One of my partners is a pilot, and so he's always talking to me about landing planes on either nice wide runways, or sometimes he has to fly into little airports that have very narrow runways, which he doesn't like as well obviously. I think about multifocals as like you're trying to land a plane on a really narrow, tight, short runway, and it's just not very forgiving. You just have to hit your marks, and there's going to be times that you don't and that's where we have other technologies like laser vision correction, lens exchanges, etc.
It really seems like the opposite is true with the Symfony. You've got this nice wide runway, and even the glare and halo issue hasn't, at least in the day that I've seen in my small cohort of patients, hasn't really been an issue.
To me, I'm actually just trying to think like, "All right when would I not use a Symfony? What are the real contraindications?" Obviously if someone's got macular issues that's a no-go, glaucoma, weird topography. Obviously those are no-go’s, but what about patients who've had LASIK in the past or PRK? If they've got a pretty normal ... they don't have a lot of higher-order aberrations or doing pretty well, would you do a Symfony on a post-LASIK patient, for example?
Yeah, I definitely would. I think that this all comes down to informed consent and discussion with the patient. You can have great outcomes with Snellen acuity and objectively feel like you've hit your mark and done all the right things, but the patient can still be unhappy. That doesn't have to be even a post-LASIK patient, but LASIK patients and I've had LASIK myself and I also tell patients and this is ... I'm going to have cataracts at some point in my life, too. As each of these generations come out of different technology, I think about, would this be something that I would be wanting to or willing to use for myself?
I've been pretty hesitant prior to this technology, but with Symfony actually I feel a little bit more comfortable with that concept. I have heard from other surgeons outside of the United States that have used it in post-LASIK patients, primarily post myopic laser vision correction patients, and if they have a pretty nice looking clean topography, they're excellent candidates, and they can do quite well. I think this actually does really supplement our ability to approach those patients with greater confidence and really get a good result. Just like anything else, I think the things you mentioned, the glare and halo issue for all patients seems to be pretty minimal.
There are some patients who really do have problems still, as there is with any lens. I think it's really important when patients are paying some extra money, a considerable amount of extra money and they have such expectations, I think it really is important to still bring up the possibility that things usually work the way we want them to but sometimes they don't quite work out that well. Let's just be open in terms of the conversation. “We expect this to work nicely for you, and I think it's a good choice for you but make sure you keep us informed.” I think that those sorts of open conversations those come out of my experience of working with patients in studies, even in this study.
It's actually gotten to be such an easy process because when you take a patient into a study you have an open book here. You're going to talk about what this technology is, what are the pros and cons, and what are their options. Patients are truly electing to let you do this for them in uncharted territory, at least in the United States in terms of technology. That just carried forward into just a general concept of approaching patients for me.
Yeah. I think that a lot of times patients are however you are. If you tell patients or if you approach patients with a great deal of hesitancy and anxiety that you might have glare and halos; we might have to yank this lens out, and sometimes there are some really bad problems that happen with that. While that information can be correct a lot of times, the way and the manner in which you present that information, also your own confidence in your skill set can really determine the message you're communicating more so than just the words you're saying.
I remember earlier in my career, before I'd done too many lens exchanges or really had much experience with that, it was with fear and trepidation that I was talking to patients about multifocal technology—promoting it, but also being a little hesitant about it. That's not a great way to go into a patient experience; it's not a great way to go to the operating room. I guess as my experience has gotten broader and I feel a little bit more comfortable, it allows me to have a conversation that's really much more natural to the patient.
Like you said, it's like we have this technology. If I were having cataract surgery today, I would put a Symfony lens in my eye. “I'm really excited that I get to have the opportunity to use this lens in your eye, but with every technology there are sometimes patients who will have certain symptoms. Sometimes those go away, sometimes they don't, and if it's a problem for you, we'll take care of it.” That's basically how I leave it, and that's how I honestly feel. If there is a problem, we'll take care of it, don't worry about it. We're going to get you taken care of. I think having that is a really important step in approaching refractive cataract surgery. It's hard to do that if you don't feel like you have that comfort level with taking care of the issues afterwards.
Well, just having a plan to take care of them. You may not feel comfortable doing a lens exchange, but certainly probably you’re in your own practice or someone across town may feel comfortable helping you out. Tapping their shoulder, having a conversation with them, but also doing a favor to your patient and to yourself and potentially to the other person who might be taking care of your patient. Prepare the eye well for the possibility that the lens is not just going in in a one-way direction.
When I think about patients who have LASIK surgery, I think all the time about this lens is going in. I feel very comfortable about the lens power of choice, but I might have to take it out, so let's just make sure it can come out.
That's right. Well, Jason, I really just want to say thank you so much for your work and what you've done and the multiple studies and other educational endeavors you've put out there. Thank you for your time tonight to talk to us about Symfony. I am really, really excited about this technology. I know you are as well. Hats off to AMO for getting this lens approved, not only the Symfony, but Symfony Toric. It's really making my day when I get to use these lenses and see the happy patients, so thanks so much.
Jason: You're very welcome Gary. It's a real pleasure. Using this technology, it makes it very pleasurable. It's just a great experience for everyone involved, so thank you.
The FDA approval of the Tecnis Symfony and Tecnis Symfony Toric was met with great enthusiasm and rightfully so. From bench to bedside this technology has been viewed as a promising treatment option for out cataract patients. I encourage anyone interested in this lens to reach out to their colleagues around them who can share their real world experience and results. As evidenced by Drs. Waltz and Jones, these are outcomes worth discussing.
I know that we'll continue to push the envelope in our pursuit to provide optimal patient care. As we do, let's chat about it. This has been Ophthalmology off the Grid. Thanks for tuning in.
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