 Should I get started. Hello. Hello. Should I get started. Okay. Good morning everyone. I guess we don't have a residence case today so I'll go ahead and get started. My name is Mark Newfer. I'm one of the cornea fellows that's been here and I hope you get the humor in my title there. If you say desec real real fast it sounds like the heck what desec what the heck why isn't my vision 2020. So I just want to talk about that a little bit. My financial disclosure is that I I'm owned and financed by the Air Force and nothing I say will actually represent anything of the government. My first presentation when I was in the military I went to Arvo and when I got back I got an email from someone I don't know who said your presentation was good but you forgot to include this paragraph make sure you include this paragraph in every presentation you give from now on so there it is. In case big brother is watching. So just to update some of you on on the desec and this is for those retina people probably aren't here. So the desec is we take out decimates numbering and then we put the graft inside and it approximates the host. So that's the desec and this is some picture of a patient that had a desec and you can look at that cornea it looks really nice and clear and if you look at that and then look at the lens and the retina and if the lens and the retina are fine you think about that patient's best corrected visual cutie should be 2020 because that's a nice clear cornea. This is what I thought at the beginning of fellowship and I was going up to Boise to do a clinic up there with a former resident here his name is Jim Tweeten and we were seeing a handful of desec patients and they looked like this and we both thought that why aren't they seeing 2020 because these patients were seeing about 2050-2070 and Dr. Tweeten had just bought an OCT so we were getting OCTs on all these patients to look at their macula and all the maculas were normal and we were really scratching our heads wondering why these patients with this nice clear cornea and the good lens and a good retina why they weren't seeing 2020 with glasses on. So I'm going to talk about that and I'm going to present a case of one of our patients but like I said they're just during this past year I've seen about six patients like this patients that have had great desec surgery and just can't quite make it to 2020. So just to start off this is a 64 year old male who was referred here for Fuchs corneal dystrophy more in the left eye than the right eye. He said that his vision had been gradually getting worse over the last few months. On his past medical history he had some atrial fibrillation, hypertension and medications to treat those appropriately. He didn't really have any past ocular history other than the Fuchs corneal dystrophy and cataracts. He wasn't taking any medications and hadn't had any surgeries. So here's his eye examination. His best corrected visual acuity was 20-30 in the right and 20-60 in the left. The slit lamp examination was notable for gutad on the right and then more gutad on the left with a little bit of corneal scarring. He also had significant cataracts. The fundoscopic examination was normal with no problems of the macula. So he underwent an eventful, uneventful fecodesect of the left eye. He recovered appropriately three months out. His best corrected visual acuity was only 20-70 on examination. It looked like the desec graph was nice and clear. Just a little bit of that scarring, central scarring remaining and then he had a significant PCO. So he received a YAD capsule otomy to improve his vision. At six months, he was not happy. His best corrected visual acuity was still only 20-40. On slit lamp examination, his desec graph looks clear again. It looks great. We told him, hey, that was a great transplant. It's a little bit of that central scarring but really not significant. His lens looked good. We performed an OCT and there was no macular edema, no epiretinal membrane. By the way, this isn't the patient. So that's not a hit the violation. That's actually my father-in-law. That's the picture I took after I asked him if I could marry his daughter. So here's our patient. Here's his corneas. And once again, you can just see a really nice, good clear cornea, a good clear graft. And then if you look, there was a little bit of the central scarring but very faint, very faint haze. Wouldn't be affecting his vision. Definitely not to a 20-40. So I want to, you know, I'll incorporate some of his exam findings as I talk about this. I want to talk about why patients that have had desec aren't achieving 20-20. And I think this is important because you'll see more and more desec patients in your clinic because this is the standard of care for Fuchs corneal dystrophy. And it's important to think about, you know, why they're not achieving the 20-20 vision. There's four reasons that I've found from discussion with Dr. Moschvar, Dr. Mifflin in doing a literature search. One is the interface haze. The other one's high-order aberrations of the posterior cornea. Another one is the prismatic effect of the donor tissue that Lloyd talked about a couple months ago. And then the last one is an irregular anterior corneal stigmatism. So I'll talk about those. So there's been a couple articles where they've done confocal microscopy on these patients. And they found that at the interface there's been this haze with these highly reflective particles. And they feel that this could be affecting vision. This is something we don't see in the slit lamp exam, but confocal microscopy shows it. This author followed these patients over six months and found that the haze improved but persisted over six months. I thought that was interesting because usually at a month out of the desec, their corneal grafts looking very clear. The cornea looks clear. But it's interesting that their vision doesn't improve for months later. And it could be partly because of the interface haze. The highly reflective particles are thought to be possibly from the microcaratomes and shavings from that, mybomian gland secretion, just any kind of debris that gets on the stromal tissue as we insert it into the eye. A group from UT Southwestern wanted to look at the higher order aberrations of the in desec patients using the Penta cam and they took a control eyes PKP eyes and desec eyes and perform the Penta cam on them and prepared and compared them. And what they found is that there was a significant difference between the PKP and control eyes, high order aberrations of the posterior cornea, compared with the desec eyes, and their higher order aberrations of the posterior cornea at the six millimeter optical zone. And here's a picture that will show that. So you can see here, here's the anterior surface looking at the higher order aberrations. And what they found is that for the desec patients, there wasn't much of a difference in C and D or just two different desec patients. Nothing significant. There's not much difference between the anterior higher order aberrations, except as you would expect with the PKP, there was a difference in the anterior higher order aberrations than the control. Looking at the posterior, they found that there wasn't difference between the posterior between the normal and the PKP on the posterior, but you can appreciate with the desec patients, there was a significant difference in higher order aberrations. And we feel that this could be contributing to some of the decreased vision. So something that Lloyd mentioned a couple of weeks ago in detail that probably applies to our patient too, is that there's, you can have a prismatic effect of the donor tissue as it's on the back of the cornea. This kind of starts at the microkeratome and the tissue punch. Sometimes you can get an eccentric cut. And so instead of being this nice oval shape, or circular shape, you can get an oval shape. I feel that this can kind of can lead to a prismatic effect as it lays on the back of the back of the cornea, and isn't even, you can appreciate here from this paper by Huck Holtz, that over here, the corneal thickness was 212 microns, and it was greater than 100 microns different on the other side. There's in this paper, he talked about the hyperopic shift because of the posterior curvature of the desec. And if you think about this hyperopic shift that you get from the posterior curvature, and then the change in the diopters as you go from one side to the other, you can definitely get a prismatic effect kind of goes back to Prince's rule, where the farther out you are from the the optic zone, per dioptery, you get a more prismatic effect. And the same thing could be happening with our desec patients. So let's look at our patient. This is the his OCT. And it looks pretty good. Looks pretty even, not perfectly even. Let's look at his pentakam. Now this is his right eye. And this was the eye that didn't receive surgery. And you can appreciate the pentakam it shows a thickened cornea as you would expect with someone with fuchs. And then you can look at the posterior float here. And it looks pretty symmetrical. Let's look at his eye that have the desec surgery. So very abnormal, very interesting how this says that near the optical center, it's thinner, and then it gets very thick, going out. And that's kind of what we were seeing with huckholz's picture back here, this thickening. And then look at how different the elevation is. It's in the positive range here, negative range there. So this discrepancy between the sides, or the unevenness or asymmetry could be causing this prismatic effect in these desec patients. Yeah, desec. That's from our okay. And then here's another topic that I want to talk about that I've been researching recently, the irregular stigmatism. And just to kind of give a little background, way back in 1898, they started a seasonal keratotomy. And this was popularized more by our Russian friend with RK, he found that, as you made these corneal incisions, there was flattening and incisional meridian and steepening 90 degrees away. Back in 2006, price and price published an article where they described this new technique called venting incisions. During this time, it was hard to keep the desec graft attached to the host. And they found that if they put these full thickness incisions, three to four of them mid peripherally, and that they could have the aqueous fluid between the interface egress through these incisions, and that would help the donor tissue approximate the host tissue better. So here's a picture of a patient after surgery. And you can appreciate the venting incisions here. Just small 15 degree blade incisions. Now here's his topography. And the question is, can you see the venting incisions help highlight that? So there's the venting incisions. So you can see that they have that effect of flattening and steepening. And as a result, they kind of create this irregular corneal astigmatism. So here's a patient and the question is how long does that last? Here's a patient one year out, you can still appreciate where the venting incisions were these flattened areas here. Okay, here's the same patient two years out. You can still see the venting incisions areas. And now four years out, still this kind of irregular stigmatism from the venting incisions. So what I did was took a cadaver eye, did a topography, and then performed immediately afterwards for venting incisions of the six millimeter zone. And you can appreciate get this irregular stigmatism from these venting. So that's also could be contributing to these patients inability to achieve a 2020 with spectacles. Just in conclusion, here's some of the reasons that I found that patients aren't achieving 2020 even though they have good clear corneas, good maculas, and a good lens. And it's from the interface haze, high order aberrations of posterior cornea, prismatic effect of the donor. And that's a good point. Maybe we should measure and be more precise on how far apart they are and how symmetrical. And maybe that would improve it. Yeah, on the the patient I presented, we did do a hard contact lens of refraction on him. And he still was only able to achieve 2040. You know, but as I was showing, I was wondering, I wonder if it's more of that asymmetry in the posterior curvature of the cornea. Great. Well, thank you. This is my last slide. Those are my corneas. That's a good treatment. Can anyone guess what my case were or my prescription was before the PRK treatment? I was about a 45 average K and a minus eight. Okay, well, thank you.