hi my name is Greg Maloney from Sydney Australia I work in private practice at the Mosman eye centre and in public practice at Sydney hospital all my work in this area is funded by the Sydney Hospital Foundation and current trials are sponsored by Sydney University the purpose of this video is to share our experiences with decimator access without endothelial care a + T or D wick I'm going to also share some animations and some surgical videos that will hopefully help any doctors out there contemplating this operation and maybe help them communicating with with your patients as well we've been using this operation as part of our treatment algorithm in fixed dystrophy for around the last four years with generally positive results and we do feel that has a role here's a photo of our first patient done who remained stable for years post-surgery I'm often asked who we feel like candidates for the procedure and at the moment we feel this is for patients with the fukes dystrophy who suffer from debilitating glare or difficulty non-driving the reduction in best spectacle corrected vision in around the twenty thirty to twenty eighty range usually patients with focal edema in the setting of folks with a clear periphery and critical to the operations that there is a healthy peripheral endothelial cell reserve we measure that in all patients with a confocal microscopy prior to surgery but an exact cutoff for cell counters is yet to be defined are but rarely we we accept patients with more than a thousand cells countable but patients it's likely that patients with less than this would possibly still have some success and they should otherwise be contemplating a d'emic and lens status doesn't matter if a kick or a suit of a kick I think it's worth discussing for a second the rationale behind the operation and to cover that there are two concepts that I think if have opened up this operation as an intervention the first is that are during the evolution of endothelial care plasti they've been many case reports of spontaneous clearing of corneas despite non-attached demek grafts from the melis group and there's also been for many years case reports of spontaneous clearing of Decimus defects in the setting of cataract surgery or other intraocular surgery and without the placement of a graft this lead has led many surgeons to the logical next step which is if guitarra themselves are responsible for creating a reduction in visual quality can they be removed selectively without transplanting a graft and can we rely on that healing capacity of the endothelium to clear the cornea that of course will be variable between patients and that's the the main challenge now that we're we're facing with this operation is that predictability of endothelial healing and edge setting or in it with each patient with respect to the study of guitarra there's a very useful video that's on available on the cornea society webpage from the ship and sigh Institute demonstrating that there is a certain size of guitarra across which the endothelial will be unable to form a monolayer if the guitar a on the inner surface of the cornea are small enough then the endothelial cells can have over that defect but if all that excrescence but if that guitar gets to a large enough size then they will aggregate it around the edges that's visible even on light microscopy where you can see an ethereal cells draping themselves over guitar pave a certain size that contortion of endothelial cell morphology is visible when you look at endothelial cells migrating across posterior corneal defect here we see cells migrating over this decimator Exynos margin which cannot be more than 10 to 15 micrometers in size but still induces enlarged stretching and elongation of the endothelial cell cytoplasm and it's not difficult to imagine that that has to be a finite capacity so aggregated guitarra will cause light scatter glare and blur reduction in visual quality aggregated guitarra of a large enough size will disrupt the endothelial monolayer and cause a focal edema and it's the removal of those guitar a that's that's critical to visual rehabilitation in fix dystrophy in these early stages that animation we've been useful by the way in communicating this surgery to patients and that's uploaded as a separate video if anyone wishes to show that when we begin the separation we became quite excited by the detection of what we felt were mitotic bodies in the peripheral cornea on confocal microscopy we saw numerous quadrants demonstrating by lobe nuclei segmenting cytoplasm hyper chromatic nuclei that we felt might indicate that we were triggering some mitotic ability by removal of cell-cell contact inhibition with this operation time and analysis of peripheral endothelial cell counts would show that in almost well in all cases of Derek the endothelial cell counts trend downwards so it's mainly migration of cells to the center to cover this defect that is the healing force rather than mitosis and creation of new cells and that just highlights the need for peripheral endothelial cell reserve for this surgery to work moving on then to discuss how we do the surgery when we commenced this this operation you wouldn't think that there were many technical points necessary to learn we're doing in this matter excess it's a stepper or familiar with but what we've come to realize is that the surgical factors are in fact probably very important in determining the outcome of the operation firstly limiting the size of the decimator axis is critical and we know from series published series already that a large size decimeter axis is likely to fail in the short to medium term so we keep all of this matter exercise us to under four millimeters when you're creating a four millimeter essentially a four millimeter optical zone then that has to be centered well and there's something that we've we've come to learn as well I'm so pre-op centration of the all marking and pre-op people Center is you know I feel an important step it's very important to peel not scrape in creating the decimator excess and we'll go on to discuss that again in a second and at all times to avoid engaging stroma and inciting a healing response from macro Atta sites just to cover that point about scraping appealing rather than scraping and we did some in vitro analysis of wind creation in this surgery and here's a specular microscope picture of a wound that has been scraped to create the decimator axis and you can see there's a trench created in the stroma which those endothelial cells will now have to migrate over and there's destruction and loss of cells on the host side of the wound as well as the the center of the wound which has been stripped away and if you compare that to a cornea that has had the decimator axis peeled and you can see there's a clean cut with preservation of healthy cells right up into the right up into the edge of the wound fairly early in the process we realized there was a need for a pair of blunt grasping forceps and we looked at designing our own there is a pair available from MST and these are hoffman decimos stripping forceps which is what we now use for this operation Mike strike Oh has a similar pair of forceps with the blunt round tipped in just that he uses in he creating his decimate or excess and I believe Mike giriboy is now also designing a set of forceps a custom-made for this operation as well so there are options for you to choose but I think the main principle is have something that is a small blunt tipped and can grasp this most membrane rather than relying on a reverse Sinskey hook moving on to show a video of a typical case now I do make an attempt to mock people sooner before and the patient comes into the theater and then the patient is dilated to allow a bit of red reflex for viewing decimos membrane using calipers we mark three to four millimeter area so we know we're not overreaching I do use a reverse sinski hook just to gently initiate the tearing decimos membrane in one location off the visual axis then these are the Hoffman decimo stripping forceps available from MST we grab that small tag of folded decimos membrane and then begin to initiate it a tear this is all done under heel on it will often break and if it does I just gently fold down the lip of the torn dis amazed not attempting to initiate and you tear in another location but just to reflect that decimos edge and gently grasp it again to complete the the circular decimeter axis goes without saying during the case that we're very careful to avoid engaging Stromer in any way on exiting the I care is taken not to drag along the temporal cornea as you as you exit heal on is evacuated and that's the that's the operation typical surgery time is about six minutes and here's the post-op appearance of that patient at at three months things that we are looking for when the cornea has cleared is that the decimator axis is well centered over the pupil and there's no stromal scarring or nodule formation so apart from and delayed healing what else could go wrong well we have seen some things this is why we make an effort to Center the rectus now he's a three millimeter area strip but the area bisects the people and this patient achieved 2025 vision but not 20/20 and we wonder had we stripped the whole visual access would that be different we were so concerned about not some scoring stroma after some of our earlier cases that one point I attempted to initiate the decimator exits with forceps alone and that is possible as shown in this video and and the case proceeded in a way that we thought was to plan when the cornea did clear that you can see that we've actually grabs stroma in that initiating location and left a stromal tag which is now because that's not papered over with a graft d'emic or a decent graft and that area of scarring will stay and have stayed now for many months because it's off the visual axis this patient has improved to 20/20 vision and it's happy with the outcome but it's like either that was not central to illustrate that point just even further here's a patient who was slow to clear in our original study and had focal edema persisting over the visual axis for quite some time and when we did it a chief clearance with the use of a rock inhibitor you can see that there is a inaccurate stromal scar in a location that the stroma was scraped with a reversing ski hook it really doesn't take much to leave a or provoke a scarring response from the stroma in this surgery something curious that you will see if you do enough of these surgeries of these small nodules that appear at the border of the stripped area particularly for you scrape rather than peel the decimator exes this posterior stromal nodules will fade over time you can see here in the photo at the no satima just at the immediate post-op period and four years post-op they do become less noticeable John Miller and I were discussing this and he feels this represents epithelial mesenchymal transformation I don't believe there's any operation we do to the cornea that's truly reflectively completely neutral and dirac is not either what happens is interesting you often see as you nothing those cells begin to pump more effectively over the stripped area a thinning of the cornea here you can see essentially the topography or tomography pre-op and to the left post up and on the right the difference map there's a effectively you create a almost a thinned myopic ablation zone and that's why I believe it's important to make this symmetrical and sent it over the visual axis and we do see some small hyper optic shifts in these cases postoperatively patients receive topical antibiotic four times daily and initially we continued that for a week but we have to remember that in the presence of micro cystic edema which these patients will have for a period of time postoperatively that's a break in the epithelium that's inviting infection so we may continue that if there's considerable micro cystic edema persisting for several weeks or months the topical hypertonic sailor and we also use to limit that edema in the post-operative course until they are clear and topical steroid we don't feel needs to continue for a prolonged period we would leave that in place only for a week Rock inhibitor is used in the setting of our current clinical trial the main problem we have still with this operation is knowing which patients are going to respond quickly and which patients will respond but slowly and which patients weren't responded all to the to the operation and Cathy Kobe in her study coined that the term fast slow and non-responders which i think is useful in the discussion around this operation that that variability means two things it means that every time a new modification to this operation is proposed as an accelerant of healing and that includes Rock inhibitors it will take a larger large series and detailed analysis to determine if that changes or if they intervention in significant or if we're just seeing a first responder emerge from a cohort the second problem that it creates is counseling a patient about what to expect after the surgery and the challenge that we have to overcome is to select or identify the best candidates for this surgery preoperatively for you would think that there are certain things that should emerge with time as we continue analysis and they would would probably be a younger age healthier or higher peripheral endothelial cell count perhaps a more favorable genotype with less TCF for chronically attired repeat expansions but at the moment was that information is still sifted out with regard to the use of rock inhibitors as an adjuvant to this surgery we have found this to either be an extremely effective intervention or sometimes not seem to make a great deal of difference and we do have a case now proceeding to Demick despite the use of a rock inhibitor so studies into this are ongoing and we have much to learn so what do I actually say to a patient when we're considering this this surgical option the term I uses will be taking one step backwards to go two steps forwards the vision is going to get worse for a period of time hopefully weeks only until it clears up and becomes better patience is required from the patients for a visual result and the commitment to come back to you for monitoring after the operation the potential benefits are that the surgery is very fast very little chance of inducing a cataract very little need for post-operative steroid unlike obviously in the case of a transplant the unknowns are the expected duration of a visual result or a surgical result after this procedure that's going to be defined only with with more time and make the point that we haven't cured you of the genetic condition we've just reset a degenerative process to an alias in earlier time and a graph may be required in any case it is important to know that the outcomes of d'emic after a failed dirac don't appear to be compromised in early analysis from various centers performing the surgery it's more than enough on on D WIC and so just to finally sign off from I'd like to thank the Sydney Hospital Foundation again for supporting this work and to invite anybody interested in attending a Sydney d'emic course it's run in January or February every year at Sydney our Hospital and we'd love to see more people come and come and attend thanks very much for for listening and I hope this has been of some help