 We're going to move to our second year residents. Julia Byrd is going to talk to us about corneal incisions with the new diamond keratome. Dr. Byrd. Thank you, guys. So I have no financial disclosures. I'm going to go through. This is kind of the second part of a study that Russell presented last year. But I'll go through some background and why this came about. Go through some of the methods and results from the study last year that was already completed and then talk about what we've done with this new edge strength resistance study, and then talk about the QI project I've been involved in as well. So sutral is clear corneal incisions kind of came about in trying to figure out ways to make cataract surgery more efficient. And there are some advantages to doing the clear corneal incisions, which include decreased corneal astigmatism, decreased cost if you're not suturing every single incision that can be beneficial. When people get really proficient at this, the ease of creating the incision is really important. And you can become much more efficient at doing this. But as this technique has kind of evolved, people have started to question or just look at some disadvantages for doing these incisions and looking at the question of wound leak and postoperative hypotony that causes potentially an influx of fluid into the eye, which potentially can increase the rate of endophthalmitis. And with these incision, there is some variabilities in wound architecture and size. Thinking about postoperative endophthalmitis, it's not super common. So studies depends on how many you need a huge patient population to really get good rates. And so rates of endophthalmitis vary depending on how many people are studied and where the location was, lots of variables. But rates have been reported between 0.07 and 0.09, 3% of cases, and variations in that range. But there have been reports of increasing rates of endophthalmitis between 2000 and 2003, and at least not any significant decrease in the rates. And granted, there's so many different variables that do play into this. And so you couldn't necessarily pinpoint the incision as the only variable. And so of course, people have looked at lots of other things in using prophylactic antibiotics, intracameral antibiotics, and all these things are important. But our focus will be on how we can maximize the safety of these incisions and the clear corneal incision. So just as a few background studies, there was a really large study done by a group out of Japan that was a prospective case control study that they took. They were comparing both the type of IOL that was placed in addition to the type of incision that was made. But they found a statistical significance in their clear corneal incision versus scleral corneal incision groups with a 0.29% rate in the clear corneal incision group in 2003. Another large retrospective comparative case control study looked at 38 cases of endophthalmitis. And 45% of them were clear corneal incisions versus 55% being scleral tunnel incisions. And in that study, there was a three-fold risk of endophthalmitis in controlling for these other things with the clear corneal incision. A study that came out of the Moran in 2005 was a retrospective cohort study, which tried to look at all these different variables and assess the odds ratio of postoperative endophthalmitis. And in this study, the biggest risk factor that they found was a wound leak on postoperative day one. So the idea is that this wound leak potentially causes hypotony, which can cause fluid to come into the eye and that contaminates things. And of course, it is still somewhat of a speculation of the mechanism. I don't think we've specifically proved that that can happen in there. There have been lots of studies that have looked at measuring IOP in that early postoperative period to prove that it's hypotony and kind of looking at that. But these models are all difficult to kind of create a realistic model. And also, endophthalmitis isn't very common. So studying it, of course, you need these huge groups of patients. And then, so that is kind of the postoperative endophthalmitis in the theories and the reasons why maybe people are why you could potentially think a clear corneal incision would have at least a slightly elevated risk of getting endophthalmitis. In terms of the wound architecture, there was a study. This doesn't exactly apply to the clear corneal incisions, but in terms of the scleral corneal incisions and the tunnel incisions, this group looked at the square incisions versus rectangular incisions and just showed that with external pressure, the square incisions were much more robust in terms of preventing leaking. And that concept has kind of been transferred over and brought forward to this idea of wound architecture and how to create the wound that would be the most resistant to external forces in wound leaks. With the diamond keratome, there is a little bit less control even in terms of the tilt and how you are entering the eye. You kind of have to be very precise in order to create this perfect police square incision. And then the other kind of thing that has come up in creating these wounds is even if you have a square incision, if it's not the correct size or there's some problem with it, you can stretch it. And then even that will be a risk factor as well to not being very well self-sealing and have problems with postoperative wound leaks. So looking through the literature, people try to create situations to mimic the real life. And it's always interesting to see how people decide to simulate these situations. Sam Asket and Group in 2013 used this force gauge to try to simulate patient-induced manipulation of the eye with pressure. And they calibrated their gauge to administer one ounce of external force. They first did this on healthy eyes, not undergoing surgery. And they showed an IOP increase that they felt was consistent with the literature of what should happen with the external force. And they calibrated their force right after cataract surgery. And they were more looking at stromal hydration versus sutures and looking at the rate of leakage. So that's just one way people have tried to have a model for the real life of patient rubbing their eyes and having these different types of incisions. So with the traditional diamond keratome, like I mentioned, the keratome tilt can really change the architecture of the wound and potentially make it less robust. Conjunctival entry can cause conjunctival ballooning and cause problems and difficulty intraoperatively. And then wound tears, where the wound tears out at the edges after manipulation during surgery can also cause problems and potentially lead to postoperative wound leaks. So Dr. Wilson designed this new keratome blade. And the idea is that the cutting edges are really isolated to the anterior part of the blade. And so that there is less risk of the wound tilt. And there's more stability and kind of safety with this blade. And at least that was kind of the theory. So the outer cutting edge is only for the first 200 microns. And then the rest of the outer edge is completely smooth and round. And then the majority of the cutting comes from this blade here. The other thing to note is that there is also a measurement line at 2 millimeters to mark where you should actually enter the eye. So in the first part of the study, the traditional diamond keratome was compared to this new blade to compare consistency and kind of consistency between wounds and squareness and to see if there was any difference in that. So Dr. Swan, Dr. Bettis, and I all did incisions with these different wounds we marked or with the different blades. We marked the wound with some marking dye. And basically, we did find statistical significance for having more consistency between the edges of 1 and 2, meaning kind of more consistently a square incision versus the diamond keratome where there was more asymmetry between 1 and 2. Another kind of side note is that there is kind of this lip that forms with the new diamond keratome versus an A versus a V that forms with the traditional diamond keratome. And in clinical practice, that might have pretty significant repercussions for how easy it is to hydrate a wound with a flap. But that was just something we noted. And I think it has to do with how you're engaging the blade. And if you don't engage it all the way, it can kind of change that lip shape as well. So then the other thing that we did note last year but didn't find statistical significance was that the year of training was correlated but not statistically with kind of improved ability to use that new keratome. So maybe extrapolating that this is potentially a better blade to use at first where you there's kind of more built-in safety mechanisms. And the skill of keeping that blade completely parallel and flat and not tilting it is something that maybe could come later. So in conclusion from that first part of the study, the new keratome did create more consistent and symmetric wounds. There weren't a lot of tearouts just from doing the initial wounds, but there were two with the traditional, one with the new keratome. Of course, the limitations are that this is not a realistic situation. The eyes were not filled with OVD. They were immobile. They were cadaverized. But then the question is, OK, so we have this wound that is more consistently symmetric. Does that have any real-life implications? And does that matter? The challenge of that is actually creating and designing a study that can appropriately answer that question. So for the second part, the objective was to evaluate if these square and consistent incisions actually translated to an increased incision edged tear resistance, which, again, is maybe hard to translate completely to clinical setting. But while you're intraoperatively manipulating the wound, there are some forces there. And so the idea is to try to kind of simulate that environment. And so for the methods, 20 incisions with each type of blade are made on different eyes. And they're human cadaverized, again, from the San Diego Eye Bank. So there's variability and kind of health of the eye and time to collection and time for us using them. The Mandel Eye Mount is used to stabilize the eye and bring it to a normal or a physiologic pressure between 20 and 30. And then the diamond keratome, the new design, and then the standard designs are used to create the incisions. And so with the diamond keratome, like I referenced before, you do have to, the entry and the way that you're actually making the wound is different. And so I think that's kind of part of the problem if you've been using the diamond keratome a lot before. But you have to enter, the tip has to be perpendicular to the corneal surface at about 45 degrees to the limbis. And then both tips have to be engaged in the stroma. And then once they're completely engaged, you can angle parallel to the stroma and then enter when you reach that mark and into the anterior chamber. So to try to measure the edge resistance, this strain gauge was modified and kind of, I guess, the point was made so it could fit into the incisions. And it was introduced into the incision. And the central scleral side of the incision was grasped with a 0.3 tooth forceps. And then pressure was applied to that incision. And under a microscope, we evaluated when the incision edge tear took place and stopped the pressure at that point. And then also noted which side or both sides had tearouts. And then the person doing the measuring of the strain gauge was blinded. So we have some negative data here to present. They actually are not. So they were not significantly different. We're only at 12 eyes, because as you guys just saw, Russell is in Nepal. But the traditional diamond keratome wounds were about 245 was kind of the mean strength there. And then in the new diamond keratome design, it was 236. And definitely not significantly different. And so we're still going to finish that. But I don't know, based on this preliminary data, that it will be significantly different. The new blade actually did have more tearouts on both sides. So that's measuring each edge here versus the traditional on one side. And so I think this project kind of demonstrates or brings a lot of challenges to light in terms of trying to design a situation that is realistic but is safe. And this is certainly not realistic in terms of intraoperative cataract surgery. But I guess the question is, with using the strain gauge and measuring the wounds in this way, is that really clinically important? And how does that really impact postoperative end off the minus rates? There's lots of variabilities. We felt like some of the time the pressure from the posterior lip, and it was very hard to kind of control how much pressure you were just isolating to using the strain gauge. And that could potentially change the results. And then the cadavers are variable in terms of their age and how any corneal diseases and how old the eyes are. And that definitely could potentially change the results as well. And then it was a little hard to know exactly when the tear out occurred. And so there was potentially sometimes where the tear outs maybe weren't identified quite as fast. So conclusion in this specific study of this wound, there wasn't any difference in the strength resistance between the two blades. I think there's definitely further routes to go to studying it in terms of clinically looking at OCT wound architecture and looking at postoperative wound leaks. Also, I mean, the other kind of maybe more important way to investigate this question, too, is external force causing wound leaks rather than this internal kind of a lot of internal force going on that lip of the wound. So of course, we'll want to thank Dr. Olson, Dr. Swan, and Dr. Bettis, and then Dr. Zog for getting us all the eyes from the San Diego Eye Bank. And now I'll move on to just address the quality improvement project that I've worked on at the VA. So the VA Glaucoma Clinic for us residents can be, it is an experience and sometimes better than others, but it really can be very busy. And it's just difficult to feel like you're providing the appropriate care that the patients deserve sometimes because of the overload of patients. And then also, though, the information that we have available to us. And sometimes the very kind of cumbersome way to retrieve the information. At the VA, I think most of us go there, but it is an electronic medical record, but our ophthalmology notes are still scanned. And so to look through past history, you kind of have to pull up each individual scanned note. It takes a lot of time. So it's really not reasonable to do that for every patient who's coming through every time you're seeing them starting from scratch. So that was kind of the reason this quality improvement project came about. So we felt like if we created a new template for Glaucoma history, it would really improve not only clinical efficiency, but also improve the accuracy and completeness of the medical records and really improve the care that the patients are receiving because then we can know what treatments have been tried and what drops did or didn't work. And when they presented and really kind of even know what type of glaucoma they have. And so lots of details that currently kind of get lost in the flow of things. So the deliverables are the CPRS Glaucoma history note and then really it just applies to this Salt Lake VA clinic. And we've started, it's a slow process because the clinics are very busy, but kind of going through especially for the really complicated patients and going through the process of trying to retrieve all the old notes and information and kind of put their history together. So I've worked with this on it with Brian Stagg, Chris Conraddy, and we thought these are my references. All right, any questions or comments? What's our next step? I mean, I think we still need to have more of them completed. I don't know, in terms of like actually, are you asking about like how to just see how well we've done with it or is it changing? Kind of looking at outcomes with it. Yeah, so I mean with the part of Dr. Jones or Judith Borner is there that you are in the groups, but part of the, you know, what we do on a regular day-to-day basis is we see problems with trying to make it better. We're QI something that adds structure and the back end of it actually, you know, best case scenario measuring impact, at the very least just following up on this. Yeah. That's kind of my next question. Yeah, so I was keeping track of what was missing. Like for instance, a lot of patients who come to the glaucoma clinic just haven't had a dilated exam in like years. Because that's just not something that's documented and brought forward. So I think keeping track of that and compiling that data of well now we have this here and then looking and seeing in the new patients that we're seeing if they're kind of on target with what we would want them to do. But that was the best measurable way, but I know it's difficult, but it was difficult to think of a way to quantify this because in terms of clinic efficiency and time and everything that was, it's hard. So I actually had the same thought, Jeff. You know, I mean, this could be, it's a nice quality, it's a nice QI project, but you could actually, I don't know how you're going to follow it quantitatively. Yeah, but you could follow qualitatively right into surveys. You can look at now and then when you call it a new system, you know, we improve the template or improve the way we do the following. Does it help patients to follow it? Or does it make the text happier? Right, at least there's some quality. That's true, yeah, I think that would be one way to look at it. I think the best way I had thought, which isn't from a patient perspective, but was more from just the, do we have all the information and how many times are we having to like go back through and we don't know what type of glaucoma they have or they weren't goniote in the last, so that was kind of what I've been doing compiling that information. But that doesn't really hit the efficiency side of it, so I think you're right. Going to your wound architecture, that's an interesting topic that we don't pay as much attention to. In fact, Paul Ernest was our honored guest at the SDRS this year. So when you get older, you can make your own guest. But one of the ways you're going to look at it, and I know it's probably too late because you're already in the study, have you thought of looking at the wound architecture with OCQ? Yeah, and that's kind of would be the next step in not moving out of the cadaver world and moving into the, yeah. That was one of the things we've talked about with Dr. Olson. I think that would be a good next move again. You can also work with bioengineer and do a lot of modeling, on a potential model. Yeah. And other planning forces and other value abilities is the extreme. And a little more for Piper than I will, for sure. Yeah, that would be nice. One comment about the wound architecture study too. Where I tried, we were not allowed to do single blade incisions. Okay. For clear-coated incisions, we had to do a step group, a pocket with a crescent and then a keratone to enter. And maybe that's some things that we can share from sclerotone incisions that there's gonna try, as much as possible, trying to create a tri-planar incision. It'd be interesting to see a comparison of tri-planar cortone incisions. There's just standard two-step open step incisions. See if there's any... And looking at... Yeah, see if there's any change in integrity of the wound. Yeah. A friend of mine is, you know, in the practice of the day, we had a specific moment where I asked, how do I do the practice? And as a group, their practice has decided that they will not do quick wound incisions unless the patient has one home on the other end of the time. Because of their rates. Just because the rates met out of the line is so they don't inject inter-camouflage antibodies. Their rates are extremely low. Just using small-tone incisions alone, so they haven't felt like they need to go into the end of the time. Okay. Thank you, guys.