 Hey, good morning. We're going to go ahead and get started. The first presenter is Jason Nguyen, and he's going to be presenting intraocular lens power adjustment by femtosecond laser. My name is Jason Nguyen. I'm one of the fellows in Dr. Manless and Dr. Warner's lab. And for those of you that were here on Friday, Dr. Manless touched briefly on this subject, but I'm excited to talk a little bit more in detail about this novel technology of power adjustment by femtosecond laser. So the overview of the talk, I'm going to start out talking about some of the background research done by the Perfect Lens Company, and then transition into talking about two of the studies that we've done here in our lab, one in vitro and one in animal study. So why do we need IOL power adjustment? Well, incorrect IOL power is one of the most frequent reasons for IOL exchange. In some years, it's up to 20% to 40% the cause of the expectation. In a study of 298 patients, only 45% of patients emerged with a refraction within half a diopter of the target. In a much larger study, only 72% emerged within one diopter of the target. And in that same study, 6.5% were beyond two diopters. So there's quite a broad range. Another reason why we need IOL power adjustment is just the growing needs and expectations for good vision. Nowadays, the patient population expects more perfect vision or freedom from glasses. And this is evidenced by just the increased usage of premium IOLs, up to 14% of cataract surgeries today, and the increasing number of refractive procedures. So what can power adjustment do? So the refractive properties of my IOL can be customized even after implantation. And this can adjust for surgical or measurement error. And in the future, we hope that this is something that can be done very quick in office and not require any type of OR time. So next, I want to talk about some of the background theory that has been proposed. So refractive index changes by femtosecondlings have been experimented with in different materials in previous years, affecting up to a change of 0.056 in glass and 0.06 in hydrogel. And some of the proposed mechanisms just behind how it happens is the light from the laser induces cross-linking within the material. And this, therefore, increases the refractive index. Or another one that has been proposed is just the local heat effects from the laser, causing a phase separation in the material, and then thereby affecting the refractive index. But the one I wanted to focus on today is the one that the Perfect Lens Company has used. And that's just using the femtosecond laser to treat an area which will cause that area to increase in hydrophilicity. And once that treated area has been treated, we see that it absorbs water. And the absorption of water causes a decrease in refractive index. And to demonstrate the hydrophilicity change, I wanted to talk about the wedding angle measurement technique. So here we have an IOL with two separate drops of water. Here on the left, the angle on this drop of water is at 64 degrees, which tells us that it's in contact with the hydrophilic surface. So that area has been treated. And the angle on the right here is at 87 degrees. So that tells us it's in contact with the hydrophobic surface. Okay, and then what's interesting about this figure is actually both of these areas are treated, but both of the drops are at an angle of 87 degrees. So it tells us that it's still in contact with the hydrophobic surface. So what happened here is actually the treated area is only within the IOL. So even though the inner substance of the IOL is hydrophilic, the outside is still in contact with the hydrophobic surface. So essentially what they've done is created an IOL within an IOL. So how did they create this IOL within an IOL? It's not this. But it's by utilizing what's called a phase wrap structure. And what a phase wrap structure is is essentially they create concentric diffractive zones. And within these diffractive zones, each of those zones has a individual power. And the summation of each of those rings comes to a total IOL power. And that's how they affect the diopter change. And what's unique about the phase wrap structure is by utilizing this technique, you can contain the entire curvature of a convex or a concave lens in one layer. As you can see here in the figure, you have a side view, a top view. And this is in C, it's a 3D view. So you can see how thin it is. It's all in one layer. And this is important because when you make this IOL with an IOL, you only have about 200 micrometers space to work with. So in effect, you're able to have a very significant refractive change in a very small area. As you can see here with a refractive at next change of 0.01 in a conventional lens, you only have about 0.4 diopter change. But in the same index change in phase wrap lens, you have up to 3.3 diopter change. And this is just a quick figure I wanted to go over of the basic setup of the Perfect Lens Company. They start with the laser and it's delivered through and shaped to the Galval Scanner. And through the Galval Scanner, it goes through an objective lens to where the IOL sits here. And the bottom figure here is just a image of the IOL holder. And I wanted to emphasize that just because what we talked about earlier, it has to be immersed in water because once the lens is treated, it has to absorb water to affect that refractive change. Otherwise, there really is no change at all. And this next slide is just quickly summarizing the results. So the company experimented with both reduction and increase in diopter. And you can see that even with the different increments, they got very close to all their targets. And the next, they experimented with nine different IOLs and they wanted to just assess how repeatable it was. As you can see in both the chart and the table, not only is the process very repeatable, but it's very accurate. So next, I wanted to transition and talk about some of the studies we've been doing in our own lab. And it's been related to basically looking at before and after the light scattering effects and the light transmittance effects of the process. So up here in the top left, we have a model I. What we do is we put the IOL in this model I and we place it here in the shine flu camera and then we assess for light scattering values. And in the bottom left here, we have a cuvette. We insert the IOL in the cuvette and the cuvette goes into the spectrophotometer. Sorry, just can't quite get it, but it goes into the spectrophotometer and we assess for light transmittance. Okay, and just the slide I quickly wanted to just show kind of that phase wrap structure that has been affected after the treatment. You can see those concentric rings. And next, with light scattering, so what we did is we looked at the light scattering values for the anterior and posterior surfaces of the IOL along with the intersubstance of the IOL. So actually on the after here, oops, the after, you can kind of see that phase wrap structure in the after treatment and you can see those rings. But what's important is that even though after treatment, there was a little change in the light scattering values, especially in the intersubstance of the IOL according to previous publications, it's not expected to have any type of visually significant effects. And here is the before and after of the light transmittance curves. Once again, you can see there's a very small change, but once again, no visually significant effects are expected. And this chart kind of wraps up our data from the immature study. What we looked at was just the change in diopters and the change in MTF. And MTF is the modulation transfer function. And what the MTF is, is essentially the quality of the optic or more specifically, how well the contrast is transferred from the optic to the image. And in summary of what we saw is, we saw a very real change and accurate change in diopters without a very significant change at all in MTF. And to kind of conclude, I wanted to talk a little bit about the rabbit study, the primary rabbit studies that we've been doing, our little patients. We started with two rabbits and we implanted hydrophobic acrylic lens, just commercially available in both eyes and we performed a slit lamp and they were on Remarkable at week one. And the company came in and brought their laser and they performed some just prelim test to kind of figure out their parameters. And after the words, we explained the lens and we sent it back to the company for further analysis. And with this picture, kind of wanted just to show the setup. So here we have what we were looking at, essentially just positioning the rabbits. We were trying to test the docking of the laser system to the actual rabbit eye. And what we found for results was that the docking system was very appropriate on the rabbit. It took quite a while, but we did eventually figure it out. And on the other results, the company was able to figure out some of the parameters they needed for future tests. So they were able to kind of figure out exactly what they needed for the deaf position, the lens in the eye or the repetition rate for the laser or just how much any energy absorption was taken out by the cornea. So from here, what we plan on doing is to experiment with some more of the long-term biocompatibility of the treatment, and then just to see how well the treatment does in living tissue, okay? To kind of wrap up, obviously with something like this, it can be very powerful. It becomes mainstream. We can use it in adult cataract surgery for immediate quick adjustment in office for ideal lens power. We count for surgical errors, eye, hotel, de-centration. And we can also use it in pediatric cataract surgery because as a child's eyes change with time, this process actually can be done multiple times. So we can adjust as their eyes change. And I think the most important thing is this is widely applicable. You can actually do this process in any type of hydrophobic acrylic lens. So as opposed to some of the other things on the market, this really, you could use it in many different cases. And I'd like to thank Dr. Manlis, Dr. Warner, my co-fellows, Joe and Jason for my references and any questions? Dr. Betty? So the NTF values know how those compare to a multi-focal lens with concentric rings. And if you don't, maybe Nick or Lilliana does. And why is it a big difference? Why is this not like NTF as much? I didn't get that last part, I'm sorry. Why is that NTF? So with MTF values, quality, right? Yes. With a typical multi-focal lens, what are those values compared to these values? If there is a difference, why is that? Okay, yeah, I'm not quite sure. So Jeff, actually the MTF measure measured before and after treatment and it's like a monofocal lens. The change was like insignificant. So it compares much better to NTF of a multi-focal lens because actual multi-focal lens has refractive rings on the surface and the surface depends on the company. This is within the substance of the lens and it's different. Everything is one single layer. So it's a very different mechanism. So NTF is like one of them. Another question? Just really quickly. Have you done any longitudinal studies to see how long and is it really possible that over a lifetime this could be adjusted for pediatric patients? So I mean, I can just comment on what was done so far but the majority of the projects is doing the in-vitro phase and now we decided the in-vitro. But in theory, this can be adjustable multiple times. So we have to go for the biophysical studies to see if there is no pitching of some kind of problem or something, but in theory, with the technique itself, it can be dropped a lifetime. And it's interesting because if you think about the California project, you have limits, right? So once you're locking the lenses down and with the California project, you have to wear those duty glasses for two weeks after surgery and with that, you don't do anything. With the California, you need a specific lens. This one is actually a lens. It could be quite interesting. You know, the advantage of this technology is just the fact that you can use it on any lens. And so on the light adjustable lens, you have to choose that patient ahead of time with only that lens in and then adjust it later. This could be anybody who's had cataract surgery with a lens in there at any time afterward and this would work on, you know, modifying the surface of that. And this is not a technology that has to be locked in like you do with the light adjustable lens. And so at least in theory, you could do multiple changes on this and that would be really advantageous, especially in a child who has, you know, implant placed at an early age and then of course their eye grows as they get older and it changes the refractive air and so you could be able to adjust that lens multiple times as the child grows older. Similarly, people are starting to think totally out of the box you could put a multifocal pattern on this eye a while and see how the patient does and how the patient has significant dysphotopsies and other issues with it. You could literally reverse it and put it back to where they were. So this has a broad potential on what could be done with this technology. What percentage of US lenses are hydrophilic? So I don't know the number off hand but I would say at least 90% just up the top of my hand. I think if I remember correctly you may not want hydrophobic. I'm sure hydrophobic right on the back of your hand. Right, so maybe 10% of the people that have this have this in the US, at least. Now I mean if you work with any lens it's not hydrophilic. It's not hydrophilic but it works on hydrophobic. Yeah, right, that's what I mean.