In this episode of The Spotlight Series Podcast, host Mario Nacinovich speaks with Damien Gatinel, MD, PhD, of the Rothschild Foundation in Paris, live in person at the recent American Academy of Ophthalmology 2025 Annual Meeting. This 3-part mini series of The Spotlight Series focuses on the recent FDA approval of the first trifocal intraocular lens (IOL), FineVision.
Mario Nacinovich:
Welcome to The Spotlight Series Podcast. I’m your host, Mario Nacinovich. Today, we are reporting from the American Academy of Ophthalmology meeting in Orlando, Florida, and we are shining a spotlight on the evolution, the science, and the clinical impact of trifocal intraocular lenses. Joining me is Dr. Damien Gatinel, a recently appointed professor and recognized thought leader in ophthalmic surgery and lens innovation. Dr. Damien Gatinel is the head of the anterior segment and refractive surgery department at the Rothschild Foundation in Paris, France, renowned for his pioneering work in intraocular lens optical design. He holds a patent for the first diffractive trifocal IOL, FineVision, and has received more than 20 international awards for his research and innovation. He has a PhD in applied mathematics, is widely recognized for his advancing ophthalmic science and surgical techniques.
Welcome, Professor Gatinel.
Damien Gatinel, MD, PhD:
Thank you.
Mario Nacinovich:
Professor Gatinel, to begin, for our listeners, could you briefly describe what trifocal intraocular lenses are and explain how they differ from traditional either bifocal or monofocal lenses?
Damien Gatinel, MD, PhD:
Yeah, that’s the same point. The trifocal lenses specifically address the 3 main distances that we need in current lives. In the bifocal era, people enjoyed 2 islands of clear vision: distance, which is 4, 5 meters and beyond, and the reading distance for books, paper. But we moved in a kind of digital age where we have those screens, computer screens, digital screens really become a kind of important distance vision, and the trifocal lens, again, addresses all these distances and must deliver the 3 distances to the patient. This is what they are, and this is what distinguishes them from bifocals, which only cover distance and near, and also EDOF lenses, which are more intended to provide distance, intermediate vision, but near cannot be promised, as opposed to trifocal lenses.
Mario Nacinovich:
That’s a change in our habits, a change in our lifestyle that dictated that. Was there a clinical need that drove the pursuit of true trifocal technology?
Damien Gatinel, MD, PhD:
Yes. When I was implanting bifocal lenses, that is 15 years ago, my patient came back to me and say, “My distance is okay, my near is okay, but when I work on my desktop or laptop, I need to really move backward or forward because this distance, I’m not comfortable with.” This is how the idea started. In the beginning, we didn’t call it trifocal lens because obviously it was more like a project to bring patients in a more comfortable situation during hours of work where they had to really work for long hours in front of the desk. This distance is usually beyond the reading distance. Reading distance is 40 centimeters, I don’t know in inches, but for the screen, it’s more like 70, 75, 70-ish centimeters’ distance. Again, there was a trough in the optical quality with bifocal lenses, which we had to feel to make not a kind of bifocal contrast curve, but a continuous, extended image quality from distance to near encompassing the intermediate one. That’s how the project was born, and that’s how we were really triggered to do it. Again, because it was initially a medical unmet demand.
Mario Nacinovich:
For our listening audience, some may be general medical practitioners, some may be ophthalmologists, some may be sub-specialists. Can you explain a little bit more about the optical principles that allow trifocal lenses to provide that spectacle-free vision of far, intermediate, and near distances?
Damien Gatinel, MD, PhD:
Yeah, that’s a good question. It’s very important because there’s a lot of confusion in some ways now because there’s so many lenses on the market. But trifocal diffractive lenses work under the principle of refraction and diffraction, so you can really understand them as a monofocal lens, which would first make sure that the distance visual quality is good. They are aspheric, this is a carrier IOL on which you add a diffractive pattern, and this diffractive pattern acts like a light splitter. What you do is you adjust the height and the width of this grating of these little steps so that if you follow some optical rules related to diffraction, I’m not going to explain, basically, you can design a diffractive pattern that will split the light towards distance, intermediate, and near, providing that you adjust the width and the height adequately. That’s how it works.
It’s quite important to understand that really, in a nutshell, those lenses, they copy-paste the distance vision to other distances. Why I’m saying this? Because EDOF, extended EDOF lens, aspheric lenses, they don’t work under the same principle. They have to make a kind of compromise between the distance and the near in a refractive way, which means that on the lens, if you want to provide not only distance but intermediate, for example, you need to have a zone where there is a kind of extra power, refractive power, and that will create a little island of myopia in the lens to make it simple. For intermediate vision, you would need a 1.5 add. That will distort a little bit of distance. It’s like a bit like presbyopic, you compromise a contrast and sometimes the sharpness, but diffraction is good, as opposed to maybe some… Not rumor, but perceived feeling that all diffraction means halos, etc.
Diffraction means also optical quality in some ways because, again, you copy-paste good distance vision to other foresight, and it acts like, again, a kind of a light split. Of course that creates, of course, specific optical quality. But again, what is important is that it’ll bring the distance you adjusted very sharply that if you want an addition to make people read, you will deliver what is promised. You don’t have to compromise the distance vision in a way that other aspheric lens do, where usually they have a central myopic zone, I say myopic in terms of extra power for the intermediate vision on even the near, and that’s not what you do with diffractive lenses. To make it simple, diffractive lenses in the middle of the lens, it’s for distance purely, and that’s very different because most either of lenses in the center is for intermediate or near, and that’s compromising vision sometimes.
We have patient with diffractive lenses, they say, “Oh, distance is not as crisp as maybe I was expecting.” Whereas with diffractive IOLs, the distance is very sharp in bright light because the impact of the other foresight is not so much impairing the vision as a compromise in distance. I’m sorry for the long explanation.
Mario Nacinovich:
No, I think our audience would be very interested and intrigued in hearing that because previously you’d have to make a trade-off. Right now there’s no compromise.
Damien Gatinel, MD, PhD:
Yeah. The trade-off is light split, and it creates a different optical impact than, again, a spatial refractive zonal change, especially when it’s in the center of the lens, will impact distance vision. That’s physical optics that I would say in a more scientific way, that higher spatial frequencies, which are the details in the image, are more affected when you use those refractive tricks, and when you use diffraction. When you use diffraction, you can convey those details to all foresight. Of course, we’ll have to compromise a bit because the light is split, but in outside situation, there’s so much light between a bright day, like in Florida here, to this booth, the magnitude of light intensity is probably a kind of a 10 to the 6 power. When we go out, there’s enough light for the retina to be happy. You can really split light and make sure that, again, this optical quality is preserved.
Of course, when the light is dimmer, then you can have issues because light has been diminished by a million or 10 million, and then the photons are more precious for the retina to catch. That’s where all lenses which are not monofocal can be a bit taken in difficulty. But the FineVision has been designed so that, for example, with apodization, when the light is dimmer, the pupil dilates, of course, to catch more light, and apodization makes sure that the light which is brought to the retina is more for the distance foresight and for the other ones, because apodization means the steps in the peripheral are lower. If you go with this reasoning, if you have a step which is new, there’s no diffraction, so it’s only for distance.
This design, which is specific to the FineVision, this apodization is quite a key element for the success of the lens, I think, because again, it makes the energy rendition gracefully balanced in bright light to pre-constructs. You have a lot of light, you can read, you can see at distance, that’s fine. When you need light, and especially when you are outside and you want to…
Mario Nacinovich:
Or the light of a restaurant.
Damien Gatinel, MD, PhD:
Yeah, or drive, the pupil will dilate. But this apodization will make the percentage of light distributed to the distance foresight, far foresight, higher by an amount of almost 2 compared to the small pupil. That explains why patient will not be in such difficulty as if they would keep a kind of ratio of 50… Sorry, 20, something like that. It will increase relatively for the distance. The other trick to preserve optical quality is to make the steps a bit smoother. This is convolution. Convolution is a mathematical tool, which again, make a tip initially sharp, not as sharp, and that’s… For a knife, it’s not good, but for optics…
Mario Nacinovich:
For a lens.
Damien Gatinel, MD, PhD:
For lenses, as long as you don’t do too much, but if you fine-tune it, there’s a very nice effect, which is, you remove the unwanted diffraction. Light behaves like waves, and you can understand that if you have a sharp tip, light can go all directions when it hits the tip, or when it goes through the tip. But if it’s rounded, that will make the light distributed in a more regular fashion, and therefore you avoid the risk of glare and visual symptoms, unwanted visual symptoms. Apodization and convolution, which is called CoPODize, I think by BVI, are 2 desired features, I think, to make trifocal diffractive lenses efficient and well-tolerated.
Mario Nacinovich:
I think we’ve definitely set the stage for trifocal lens science.
Damien Gatinel, MD, PhD:
Yes.
Mario Nacinovich:
I would like to take a step back for our listening audience to understand a little bit more of the historical context. Could you give us a brief history? Describe the innovative approach and the milestones that led to where we are today with the development of FineVision.
Damien Gatinel, MD, PhD:
Okay. As I said, I was, and I’m still a cataract surgeon, ophthalmologist, and I was doing bifocal implantation in patients who want spectacle independence, but I could not reach true full spectacle independence because of intermediate vision. At that time, I was…
Mario Nacinovich:
It was not possible?
Damien Gatinel, MD, PhD:
Well, no, they didn’t have it because, again, there were only 2 foresight and no intermediate foresight because these lens were designed in an era, late ’90s probably, where intermediate vision was not as important as it is today.
Mario Nacinovich:
To your point, socially about that screen.
Damien Gatinel, MD, PhD:
Yeah. Historically, there’s a nice coincidence that the first iPad was introduced on the U.S. market. I remember it was ASCRS Boston 2010, and people were going to the store to buy those tablets because they were launched in the U.S., not in Europe. This same month was the launch of FineVision in Europe, coincidentally. Tablets are usually… because it’s heavy, so the people put them on a table, or on their lap, and it’s intermediate vision. It’s a nice historical overlap or coincidence. I was collaborating with PhysIOL for other project. Believe it or not, I designed the asphericity of the monofocal, PhysIOL, the company that designed the trifocal with me in those years. In the mid-2000s, I had designed this aspheric lens for them, and when we discussed how could we improve on the current market, this intermediate vision issue became what was a trigger for this project to start with.
With Christophe Pagnoulle, the R&D of PhysIOL, a very smart PhD who had a lot of knowledge in biomaterial, he had patented a glistening-free polymer. We discussed together the idea of doing a new lens for not only distance and near, but intermediate, and this is how it started. As a doctor, I would go to Belgium to work in the R&D facility with Christophe. We also used the resource of the Liege Space Center, which by chance happened to be walking distance from PhysIOL facility in Belgium.
Mario Nacinovich:
Just coincidentally?
Damien Gatinel, MD, PhD:
Yeah. This is a very famous academic astronomical center where they work on satellite, optics, telescopes, many things. We could use some optical engineering resources there to fine-tune the profile and do different simulations. That’s important also because I think the lens was launched 15 years ago in Europe. Now it’s just FDA-approved. You may think, oh, in between, new trifocal lenses were launched. But when we decided to do this thing, we could explore many possibilities in terms of trifocalities. There’s different way to achieve it, but there is an optimal way, which by chance, or by maybe nature, is the simplest. Again, we had bifocal…
Mario Nacinovich:
Simple in this case being the best?
Damien Gatinel, MD, PhD:
Yes. Yeah, simpler is the best in optics. The less tormented a pattern is, usually is the best it is, because you don’t want to… I mean, in other words, the less interaction there is during the transfer from the anterior surface to the back surface of the retina, the best it is. We knew that we had to work on the kind of economy principle, but not to sacrifice, to improve. I call this a bit the Zen philosophy, because if you’ve been to Asia and Japan in particular, you notice that this culture is really interesting because it usually go under the efficiency and simplicity. When you combine both, usually it’s also beautiful and…
Mario Nacinovich:
Harmony.
Damien Gatinel, MD, PhD:
Harmonious, yes. Of course, here aesthetics are not what we wanted to work on first, but again, we decided that if you start with a bifocal lens, what is the shortest way to achieve trifocality? Believe it or not, it’s just to alternate the height of the steps from a bifocal in a way that makes a new foresight appearing, and doing so, you don’t increase the number of diffractive steps on the lens, which is a very good news. That’s the first thing. Second, again, once we arrested the design working on this principle combining simplicity and efficiency, we optimized it by this apodization that I explained and convolution of the steps that we added to the design, and we compared this design to others. Anytime we were back to this elementary, efficient thing, we explained also this, to make a trifocal lens, you can add two bifocal designs. But when I say this, people may think, oh, you multiply the steps by 2. No. If you do this, there is a nice alternation of the steps that is making steps higher every other steps, and some other lower.
But again, there’s no extra steps compared to a bifocal. Once we understood these things, we were very happy because we really… this is a moment we felt that this would work, and that we would not create extra optical disturbances, but we could if we do it fine, FineVision.
Mario Nacinovich:
FineVision.
Damien Gatinel, MD, PhD:
Not only create a new foresight, but not sacrificing distance and near. This, again, was achieved by the fact that if you do this simple maneuver, which is alternating wisely the steps of the diffractive bifocal, you can have a better light rendition. You can get an extra 5% of light which was lost by a bifocal back into useful near vision.
Mario Nacinovich:
Was it that interplay with light that allowed that to happen?
Damien Gatinel, MD, PhD:
Right, exactly. It’s a subtle diffraction properties that if you go and calculate… Diffraction works under orders. I’m not going to cover this because quite complicated, but to make it simple, light is diffracted in the first, second, third order. Of course, the percentage of diffraction intensity is going down, but the second order of the intermediate kind of diffraction design gets useful for the near. Again, the rendition of the trifocal was better than the bifocal, which was a bit unexpected, but a very good news, because this 5% is precious to help maintaining good distance vision and not, of course, take the near and make it intermediate, like EDOF have to do, because EDOF refractive lenses really, if they want to cover near, the sacrifice or distance is too high. That’s why doctor says, “Well, I use usually EDOF lenses, one eye distance target plano, and the other eye have to make it myopic slightly.” It’s like a bit monovision. In diffractive IOL situation, you don’t have to use monovision. So stereopsis is much better. Both eyes have the same distance…
Mario Nacinovich:
The brain doesn’t have to work that hard?
Damien Gatinel, MD, PhD:
In visual optics, when you are a refractive surgeon, something you understand is the effect of the sum of the eye is superior to the addition. What I’m saying…
Mario Nacinovich:
Synergistic?
Damien Gatinel, MD, PhD:
Synergistic, like with 2 eyes, you see not twice better, you see much more better. We can tell this because most doctors know that hyper-optic patient plus 1, when they come to your office, they come and complain about the near. You ask them, “What is your distance about? Excellent.” When you refract them monocularly, they hardly read 20/20. They would do 20/25, 20/25 because plus 1… But when they get binocularly reading, then they move sometimes to 20/15 because the brain is where the vision happens. To me, binocularly is also a key element to get patient satisfaction because when you do the first eye, they usually are very happy because when they are having a cataract, this is improvement. When you second eye, the second eye is not just adding to the first, it’s like…
Mario Nacinovich:
Doubling, tripling.
Damien Gatinel, MD, PhD:
Yeah, yeah, yeah. Potentializing the vision, and that’s very interesting.
Mario Nacinovich:
It is. No, and thank you for sharing that. I think we’ve learned a lot about the development, and it sounds like a great innovation, but I’m sure that there were some particular challenges along the way as well that we haven’t talked about. Did the team face any material science or optical engineering challenges along the way during the development of FineVision? What were the things that challenged the team in development?
Damien Gatinel, MD, PhD:
I think it was not so much a technical challenge because PhysIOL had the capacity and the technology to create those diffractive elements. It was more on the market a fear that introducing what we decided to call trifocal lenses would make doctors afraid because they would feel like, oh, that may bring more disturbances than bifocal. We knew…
Mario Nacinovich:
They were already dealing with a lot of issues from bifocality?
Damien Gatinel, MD, PhD:
Yeah, but we knew that because we made a apodized, simple and efficient trifocal designs, we would probably avoid those pitfalls, but the marketing department was interested in this approach, but also was reluctant, maybe, to even say trifocal, or explain that this would introduce a new foresight because they would be afraid that the perception of the market would be… it’s too complicated, or it will create another extra visual disturbance. The conceptors, me and Christophe, and the technical part of the company, we insisted to be transparent because we were confident enough in the fact that it will work, that this had to be named trifocal. But at that time, this trifocal, which is gold standard today for multifocal, did not exist. Everything which is new faces the issue of the…
Mario Nacinovich:
Awareness, education, adoption…
Damien Gatinel, MD, PhD:
Awareness, education, conservatism, in some ways, and medicine is very conservative in some ways. It takes a lot of time for a concept to become popular. Not so much for the trifocal, I would say, but at that time, that was where…
Mario Nacinovich:
The only challenge was really the fear of what we are calling it?
Damien Gatinel, MD, PhD:
Exactly. Technically speaking, there was no challenge, and the prototypes were made quickly and tested under optical benches. That’s good in optics. That’s why I like this science. What you predict is really what you get, and that’s why I like this optics.
Mario Nacinovich:
Well, also, what you manufacture is what you put into this.
Damien Gatinel, MD, PhD:
Exactly. Of course there’s sometimes adjustment to be made because the material does not behave exactly as predicted, but you can fudge it. But at the end, the equation predicted that we would have this kind of MTF curve, and we were pleased to see. By the way, I told you when I was asked to do the asphericity calculation for the monofocal, I was myself skeptical. I used the optical design tool, and when I send my file telling that’s the asphericity you should put for that power to get this effect, for three weeks, I didn’t hear anything back, and I’m like, maybe it didn’t work. Suddenly they called me and say, “Hey, Damien. Perfect. We tested it. It works. We made the prototype, and it exactly what you predict.” That’s the beautiful thing in optics, it’s very mathematically… Other science are more like empirical…
Mario Nacinovich:
Some predictability.
Damien Gatinel, MD, PhD:
Yeah, but optics, we can really predict, and using the proper equation you can really get… On the other hand, and this is a bit of detour, I love optics also because this is the light mystery of wave, particle rays, and to understand diffractive lenses, you cannot use geometrical optics. You need to go to physical optics, wave conception. That’s also what you have on one side, which is the predictability. You pay as a still kind of mystery that is, what kind of modeling should I use? Should I consider life as rays that works for geometrical optics? Refractive lenses, but if you want to understand any diffractive lens, you need to move to the wave conception, and light is both a particle. A wave, this is something classic in physics, and I’m glad that this is incorporated in my practice and in my field because this is something, still, that is almost philosophical. How can a physical phenomenon be apprehended in various ways, depending on the context? That’s something which obliges you to become yourself curious, open-minded, and humble.
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