 We'll welcome up Dr. Chris Kinratty. I don't know exactly how to pronounce his last name after one year. I've heard it lots of different ways, so I'll let him actually say himself. He's one of our first year residents on MD-PhD. If you look up his social media profile, it says that he has an interest in virus, something or others. I don't know. He's married, fortunately, so he doesn't have to worry about that. Dr. Patel. That's all right. All right, Kinratty, you're a tag. Okay, so I'm Christopher Kinratty. I'm one of the PGY2s. I didn't really know what to expect with Dr. Patel up here. You never really know for sure. But I'm gonna be talking about a project I've been working on with Dr. Bernstein, and I guess without taking him a step further, this has been kind of a project that many people in this room have had some sort of impact on, and we'll talk about that at the very end. But I've basically entitled it the interrelationships between macular skin and serum carotenoids. And so before we get too far into the talk, I have no personal disclosures to declare, but I think it would be relevant to at least discuss that Dr. Bernstein and Dr. Gellerman and the University of Utah own a patent on resonance around the spectroscopy, and we'll be talking about that here in a second. So a little bit of background on carotenoids, I'm like too loud back from the back, too quiet. We okay? Okay. So carotenoids are fat soluble pigments found in dark green vegetables and orange fruits and vegetables, with the highest concentration being in kale, and then a second member of kind of that leafy green family in spinach, but you can also see carotenoids in kind of these, in oranges and other fruits. In humans, they have been shown to have a, or at least presumed to have an antioxidant function. Three of the carotenoids that we consume in our diets are concentrated within the macula, lutein, zeaxanthine, and mesozeaxanthine by specific kind of mechanisms, and we won't really talk about that today, but they're specifically concentrated within the macula to give it the yellow pigment on fundus exam, or the yellow coloration, I guess. And these carotenoids, at least within the retina, are felt to filter basically more deleterious blue wavelengths of light to reduce reactive oxygen species damage within the retina. And so that's kind of their role. From a clinical perspective, probably the most, at least, interesting aspect from the ocular standpoint is there's been multiple studies that have kind of associated carotenoid concentrations with macular degeneration. And what were those studies? Well, so there's been multiple, and I'm not gonna mention them all, but probably the first is that patients with lower serum carotenoid concentrations are at an increased risk of developing AMD. There's been several studies that have shown that. Then kind of the opposite of that, that patients with diets high in zeaxanthine and lutein have a reduced risk of developing AMD. And then, of course, we're all familiar with the AREDS and AREDS II studies. At least with the AREDS II, suggested that carotenoids, or at least supplementation with carotenoids and a couple of other vitamins reduce progression to advanced AMD. So that's a very basic kind of background on carotenoids and kind of the clinical importance. So there's been quite a bit of research trying to develop mechanisms to basically measure macular carotenoids. Obviously we can't go in and take samples of the retina, I guess we could, but it wouldn't be great for the patient. So we've been looking at kind of surrogate markers. And probably the most or the oldest kind of method has been flicker photometry, and that's here. And it's a fairly complicated test to perform and takes quite a bit of patient kind of compliance and learning to actually get meaningful data out of it. That's been the most widely used, and that basically gives you optical density readings and we'll talk more about that throughout the talk. And that's currently at least partially being replaced by dual wavelength auto fluorescent imaging modalities, where you basically get a green and blue image from auto fluorescence and subtract the two to give you a carotenoid concentration. Then there have been other surrogates that have been proposed and studied and tissue validated in fact. So serum and using HPLC to test concentrations and then resonance from the spectroscopy, which is basically taking a scan of the skin that was developed by Dr. Bernstein and Dr. Gellerman to give you kind of a carotenoid concentration within the skin and we'll talk more about that here in a second. At least from our overall understanding of carotenoids, there's really no clear gold standard of a surrogate for basically macular carotenoid concentrations. So kind of keep that in the back of your mind as I talk. So the two kind of methods we'll be talking about in the rest of this talk, I guess. Here as resonance we're on the spectroscopy, basically you put your hand on a little scanner and it gives you a reading here. And then the spectraus, which is how we get our dual wavelength auto fluorescent images that's hooked up to an OCT machine and our photographers here incredibly gifted at using this thing. So at least in regards to measuring carotenoid concentrations or surrogates within the macula, like I already suggested, basically most of the literature has used flicker photometry or dual wavelength auto fluorescence that gives you an optical density reading at 0.5 degrees and we'll talk more about that. So don't worry too much about kind of this optical density versus volume measurement stuff. Then Dr. Bernstein actually published a study several years ago and it was kind of a question that we also raised throughout the study, but this showed that skin and macular pigment measurements did not seem to correlate in adults and they also kind of showed in children that they did correlate. So there's some disconnect there that we didn't quite understand at that point in time. And then a more recent study, and there have been several of these studies, but basically oral supplementation with lutein or zeaxanthine has an effect on macular pigment optical density readings by increasing retinal sensitivity in patients with early AMD and then like I said, increasing optical density readings. So there seems to be some direct effect that we can measure. And I've already kind of used a couple of these abbreviations and I'm actually gonna make them a little more simple just so we're not having to look at a bunch of letters. So optical density readings are basically like I have kind of hounded on already. Then we'll also be talking about volume under the curve measurements that we'll also be talking about. And I'm actually just gonna call that volume measurements just for simplicity. And then residents were on the spectroscopy and then so that's basically the skin measurement and I'm basically gonna refer to that as skin as well just to simplify things. So we basically walked into this study with a fairly straightforward kind of question. And basically a mathematical question and that was do more data points. So something like a volume measurement more strongly correlate with other biomarkers such as serum and skin measurements than these optical density readings that have been used for 15, 20 years throughout the literature. And then there's been some, like I said, disconnect in the literature with some of the optical density kind of studies. And so we basically propose walking into this study to systematically compare dual wavelength autofluorescent imaging to resonance ramen spectroscopy and then using basically serum carotenoid concentrations as kind of our presumed gold standard or at least something of comparison in a clinical setting. So we recruited 72 patients from retina and general ophthalmology practices here within the Moran. We basically tried to exclude no one but there were a few kind of exclusion criteria. If they didn't have all three modalities tested, we excluded them. If they had a previous diagnosis of Mac-Tel or stargards with significant or with due to the significant macular pathology, we excluded them as well. And then there was one, and I literally mean one patient had poor kind of imaging quality. And so we excluded him as well. And that was in stage of a teleform that was kind of skewing that image there. And then like I said, we tested all of these modalities in and we compared them. So the patients within this study, average age of 59 ranged anywhere from 30 to 90 years old. About half of them had a normal kind of retinal exam. About a third of them or a little less than a third had some form of macular degeneration. About a third of them were on some sort of PO supplementation obviously from kind of the retina practices with presumably macular degeneration and other forms of kind of macular pathology. And so to give you an idea of what these optical density measurements look like. So this is a scan with a spectralis and to take optical density measurements, that's this red bar here. That's 0.5 degrees from the central fovea. Then you see that spot here. We then, like I said, wanted to test that optical density measurement versus volume measurements. So we looked at a volume measurement within 0.5 degrees. We looked at a volume measurement within two degrees. So the blue circle are here. And then we went all the way out to nine degrees from the central kind of macular there that you see here and took a volume measurement there as well. And we didn't go any farther out than nine degrees because the data and you don't see it well here but gets fairly, not necessarily erratic but less reproducible. Likely due to the fact that there's some vasculature that's kind of altering or at least obscuring the clarity of the images. And so we first asked, is there some sort of support for using volume over optical density measurements? And so we took a patient, maybe I shouldn't disclose this but this is Dr. Bernstein who basically has a normal diet, has no pathology of any type, compared him to a lady that actually has maybe the first reported case of lutein crystalopathy within the macula. Cause she was taking 20 milligrams of lutein and also consuming a diet very, very high in lutein and zeaxanthine. So literally had lutein crystals within the macula. We then look at optical density measurements. They look the same, which doesn't really make sense when you have a patient that's consuming high amounts we've already shown with previous literature that you can affect optical density measurements with a diet or supplementation of some type. We then looked at volume measurements at 0.5 degrees. They look the same. However, by the time you get out to two degrees, you see nearly a two-fold difference between the patient that had this diet high in lutein and zeaxanthine and nearly a five-fold difference by the time you get out to nine degrees. So this gave us some support of basically using volume measurements in larger volume measurements rather than optical density measurements. So then we went back to kind of our group of patients that we had recruited. We did a linear regression analysis basically comparing serum zeaxanthine and lutein. So I've already told you that they've been tissue validated with basically serum concentrations and compared that basically to our optical density or volume measurements working our way out. All the p-values are significant, less than 0.01 with all of these graphs. But what you'll notice is the r-squared value, the farther you get away, well, so optical density, volume measurements at 0.5 degrees, r-squared's about the same. However, by the time you get out to two degrees with the volume measurements, you see an increasing r-squared value and then by the time you get out to nine degrees, even a better r-squared value, which gave us even further support that volume measurements are better than just single optical density measurements. We then looked at skin measurements in a resident's Raman spectroscopy and wanted to show just something that's kind of so what like this is expected, but basically with zeaxanthine and lutein, you have a nice correlation with these skin measurements. So an possible second surrogate marker using skin. And then if we look at all serum pigment, since there's more than just zeaxanthine and lutein in the skin, you get even a tighter correlation with your skin measurement. We then went back to ask the question, could you use skin measurements to basically predict optical or basically macular concentrations? And so we compared the two with linear regression, same thing, p-values are all significant, same kind of similar theme, where the farther you get away from the central fovea and more specifically volume measurements are better, much better than single optical density measurements. Giving further credence to the idea that volume measurements and larger volume measurements, so at two degrees and then even better at nine degrees are much better than optical density measurements or even volume measurements at 0.5 degrees. So then I'm not gonna show much more than this just for the sake of time, but basically we have kind of two conclusions here and we have more data to draw other conclusions on, I'm sure some of the questions will come up. But we're basically concluding from this, that volume measurements at nine degrees have a stronger correlation with tissue-validated resonance, romin spectroscopy or skin measurements and also serum carotenoid concentrations. What that means is a lot of the literature that's been using optical density measurements is unclear, but I'm sure people are probably not gonna be too happy if they've been using these measurements. We'll see, time will tell. And then we would even go a step further and say that volume measurements at nine degrees should be utilized in studies going forth. And then the kind of second correlation or second conclusion is that skin seems to correlate well with serum and macular pigment measurements in adults. And like I told you at the very beginning, there was some kind of disconnect between skin and macular pigment measurements. That's likely due to the fact that the spectralis we now have is much more reproducible so we can get more accurate, more reproducible measurements and that's why we're seeing a correlation that once wasn't seen. And so there are probably a thousand things that we could do with this going forth, but probably the two, at least that I'll mention, the first being evaluating the impact of oral supplementation. And so you could theoretically, I guess, get rate of change in a patient with macular pigment concentrations as you follow them over the time after you start them on some sort of lutein or zeaxanthine. Which would be kind of interesting to know. And I won't show you the data here, but there seems to be a fairly, there seems to be a population of individuals that seem to respond fairly well to oral supplementation and get supratherapeutic levels or what we assume are supratherapeutic versus those that only partially respond to the lutein and zeaxanthine. What that means, I have no idea. Then the second and probably more difficult question but probably more exciting question is, could you use this data and these imaging modalities to identify patients at risk of developing AMD by lower concentrations of macular pigments and potentially alter the course of the course? That's a fairly big question with a lot of variables inside of it and would take a very, very large study but probably a valid and important question. And so here are my citations and then I have a lot of people to acknowledge. These are the people that have been most kind of instrumental in it, but there are several people in this audience that have also kind of given to the cause and had their eyes dilated and imaged and then also those clinicians that have also helped us recruit patients within their clinics. So with that said, I'm more than happy to answer any questions that people have. So Dr. Bernstein will be able to speak a little bit more on that, but so if we were to go back, let me just give you a good kind of representation. So if you were to look at these specific numbers, so five-fold difference here, if we look at skin measurements, we've had two individuals with skin measurements over, let me see if I have some data here. So there've been two individuals and we've actually recruited more patients. Here's the one lady that I was suggesting with the lutein kind of toxicity. We've had literally two patients with values over 100,000. She's one of those. And so with these two modalities, so both macular pigment measurements as well as skin measurements, we seem to pick that up. What has been done in clinics, so Dr. Bernstein had her stop, her supplementation of lutein, like I said, she was taking 20 milligrams of lutein every day and had been for eight years, and then has had repeat measurements over time. And I think it was 10 to 15% change or decrease per month since going off of the lutein supplementation. So just an answer, I think that your real question is, that was picked up by Susan Turkova who just walked out, and she has golden crystals, she didn't rank in her codea, but that were not there. She had been following this patient for a long time, did a follow-up call or not, not the NB. And she doesn't have any symptoms, she had these golden crystals by a diet she was consuming in addition to her 20 milligrams lutein per day, she had a spinach broccoli kale, I'll tell you how it's truly for breakfast every day for eight years, it's a enormous load. And we specifically took her off of the, I took her off the supplements and said, don't bother changing the diet, and the crystals had disappeared already in one of the eyes, so that's why we're writing it out. Paul is similar to like the canthus dantheum that people were showing for the time. They do look like them, except they're in the fovea, canthus dantheum doesn't go in the fovea, it goes in the circle. And it's very reminiscent of a condition known as West African crystalline maculopathy, which I saw in Ghana, and it does exist, and it's something dieterrally that people eat in Africa. They thought it was colon nuts, but it's probably a carotenoid that they're consuming there. And by OCT, they're in the Henlein fiber layer. So, another comment I would just like to say, or mention on this, with the spectralis, I've worked with many different ways of measuring maculopagment, including the psychophysics and all sorts of different methods. The spectralis works very well, but it has to be done for the private practice people here. It has to be done on a high-end spectralis with two wavelengths, and the software is not released by Heidelberg yet, so it can only be done under an IRB, so there's only a few sites in the country that do that. And it dilated people. And you need to be dilated, as you would expect, but I'm very impressed with it, but it's an interesting project to just kind of see it coming together. Okay, thanks, guys.