Overview of SCORE and Comparison of Alternative Methods to Monitor Corneal Ectasia

abroad, it is a great pleasure for me to introduce you to Dr. Alan Sad of the Rothschild Foundation in Paris. Dr Sad has been interested in Corneal Activia for many years and for the last two or three years has worked with Anterion to develop Score which is a unique means of identifying and

monitor

ing Corneal Activia and we are delighted that he is here today to explain how the

score

works and how it can be used in clinical practice, not only that, thank you for doing this webinar with us and greetings to all. Thank you Steve for the nice presentation, it is a pleasure for me to be here with you and try to share with you our work, the work that I have done together with Daniel at the Rothschild foundation with the collaboration of Heidelberg, so we were.

In the next 15 to 20 minutes we will try to present the

score

to you and compare it with other

alternative

methods

available to

monitor

Indonesia. First of all, what

ectasia

is is a progressive hardening and thinning of the colony that can occur after laser examination. refractive surgery can occur, it was described after lazy, it was described after PRK and you also have two smiles and it induced a loss in best-corrected visual acuity and it is really a terrible complication of refractive surgery, fortunately it is very rare, however , it exists and we know today that

ectasia

can be primitive when it is a keratoconus but it can be electrogenic when it follows refractive surgery, when it is electrogenic it is due either to excessive removal of the posterior tissue or if we perform surgery of undiagnosed subclinical character, which is now well recognized as the main risk factor for atrogenic activation, that is why many teams, many surgeons are trying to discover what is the best way to recognize and detect the very early form of the character and Rabinovich was one of the The first more than 20 years ago to describe any specific pattern of topologies, Placido topography, to recognize suspected keratoponis or early keratocones.

You can see here on the left side of the screen some specific patterns that are bottom steepening and what they are. qualitative, so they are based on the subjective evaluation of the expert and from these patterns he also developed some type of quantitative parameters such as threats due to a biased radial axis, which is when the most inclined axis does not have a separation of 180 degrees. you have a specific angle here that you can see and also the I minus s which is the lower keratometry minus the upper measured in five millimeters, so we look at the lower automatically measured in five millimeters, average it and compare it to the upper keratonin.

The average Superior Care is automatically measured in five millimeters and when the I minus s is above 1.4 diopters we are in principle looking at a kind of suspicious keratocones, so those were the preliminary findings, however today there is no prolific system that is capable of detecting some clinical symptoms. additional care with one hundred percent specificity and sensitivity and this is due to several things, first of all, the quality of the acquisition is a variable because sometimes the patient moves, he may have an association of dryness that he thinks might not be perfect and, more importantly, it really depends on the subjective interpretation of the doctor and there were different studies and the main one was published by Renato Ambrosio and Brad Randleman and their co-authors and team which showed that there is a high variability in the subjective classification of the coronal topography. not only among soldiers but also from the surgeon himself, if one day you give a topography to a surgeon and ask him if you would do Lasik on that cornea, he might say yes and if you give him the same popularity a few weeks later, a few more months I could later look at it another way and this generated interest in trying to find a way to objectively evaluate the topography, for example, if we look at this image of this previous action curvature obtained with the previous well, we could say yes.

There is a little bit of asymmetry, but it looks like it's not very high, so maybe it's normal topography, but if we look at that patient's contralateral eye and see that he has clear vision, probably in that case we'll see this. The first image left the left eye here differently, it is definitely easier if both eyes are abnormal as in that case we can see that it is an obvious keratoconus and it is an abnormal cornea, however when both eyes are a bit suspicious , it is more difficult to give an opinion and say well in that case we will go and proceed and perform refractive surgery maybe I am not lazy but a PRK or not is more difficult to judge and definitely if you show those images to different experts they will not have the Same conclusion then there are different devices available on the market and I won't go into all of them, but what I can say is that all the devices are now trying to provide the surgeon with some kind of objective way of analyzing the cornea.

You can see that some of them are based on Placido. surveying based surveying, some of them are based on a combination of Placido and swisscani, like Rob's scan we were on previously, you have the bright floor devices that are widely used and more recently we have the devices based in oct that seem more precise in their acquisition like the previous one from Heidelberg and others and those devices mentioned above tried to combine different parameters such as the

corneal

navigator, for example, which were made by class and goal more than 30 years ago, they combined pure Placido with holy acid. parameters in an automated way based on a kind of neural network to give a percentage of similarity with normality to keratoconus to create its own suspect, making it one of the first automated quantitative

methods

to evaluate corneas.

Elsewhere, we work a lot. in what we call the scoring analyzer score for colonial target risk detection of ectasia, so together with Daniel we developed this software in 2012 originally on the offscan device and it was the combination of the above parameters, the above Placido parameter with archimetric maps. together we get a final score that analyzes the cornea and says yes, this cornea is normal or this cornea is abnormal and since 2012 there were many publications on the sensitivity and specificity of this device, we were in the first evaluation group that we reached. a sensitivity of 92 percent with a specific standard quite very good also validated in Asian eyes and others also in different ways because it also affects colonial disease and the cornea and stability probably other devices are the Pentagon, as I said, it is widely used, It is a rotating shampoo.

Imaging technique that gives you an echometric map but also curvature information and on this device you can get multiple indices shown here with specific slices that are hard to find, basically there aren't really many publications that show exactly what they are. the limit for each of these devices or each of these parameters and what exactly is the clinical significance of each of these parameters, but they were also combined all together into another final parameter, a very interesting development and very, very important in the In the Pentagon there were the indexes of relational disease that were developed by Renato Ambrosio and this represented a great advance in the interest of the pachymetric map in the diagnosis of the early form of keratoponus when we observe the speed of rotation or the difference in the thickness of the center of the periphery of patients presenting with keratoconus, Renato Ambrosio, found that there was a difference between the normal patient who creates only suspicion and the keratoconucation and there are some specific thresholds that can be found in the artistic mathematics or in the artistic average that are shown in this device and helping to detect the early shape of karate points and all those parameters in the staff pattern were combined together or at least different combined into a final D value which is calculated based on the regression analysis and when these D values ​​that You can see here at the bottom right in the last square down when it is red it means it is abnormal when it is yellow it means it is suspicious and when it is white or green it means it is not so it is a combination of all the parameters together the Galilee device is a double glow fluid system plus a Placido disk so the difference of the pentagram has a plastido disk and it has a double time flow system that is supposedly uh more precise in the acquisition of tutoriality and only There are some objective ways in Galilee to evaluate the cornea, hit their matcha they did a good job of trying to combine different parameters together, however, in clinical practice, I'm not sure this discriminant variable is widely used today, so The goal of our work with the previous OCT photographer was to try to reproduce what we do as a surgeon as an expert when we evaluate the topography so we look at the interior elevation we look at the posterior elevation we do we look at the pachymetric map Look at the interior axial curvature and let's combine the parameters obtained from all those maps to make a decision and say we're going to do a LASIK or not or we're going to do a PRK on our page, so we wanted to replicate this thinking and we automated it and how we did it so that the Imperial score is meant to be the first score available which is derived from a combination of anterior curvature or city derived parameters posterior curvature velocity derive parameters and pachymetric paths into single numbers as the score to classify the cornea as normal or as a nodule and so how did we do it?

We took a certain number of patients who had a clear normal eye on one side but on the other eye, I regret having a bilateral normal eye. There were 189 normal eyes of patients who had Lasik and did not develop ectasia due to the operation and we also took a group of 76 patients who had a four-foot scleratoconus and those patients who had friskeratoconus, how did we know that they had a formula to suspect it? was because they reached the lateral eye was a clear or clearly abnormal keratoconus, so we selected the eye association that appears normal and compared it with a normal eye from a patient who had normal bilateral topography who underwent Lasik and did not develop this addition.

That's how we were sure that the eye was perfectly normal and you can see this table is very small and you can't read all the parameters just to show you that we looked at multiple and multiple parameters over 50 parameters obtained from the device to try to determine which would be different between those normal corneas and those that look like normal corneas, but knowing that they are not normal and what we did, we discovered that some well-known parameters were different between the two groups, such as how the I minus s was statistically different between the normal group and the rule of suspicion of keratoconus, we also did the

corneal

profile and thickness in a similar way to what was developed by Renato Ambrosius, so we re-entered the map at the Cena point and calculated the average document in different terrain from the sinus point to 0.5 millimeters 1 1.5 to 2.53 Etc. of the series to obtain the percentage of increase in thickness from the sinus point towards the periphery and we found that at a certain distance from the sinus point this percentage of increase in thickness was statistically different between a patient with normal keratogonal and a patient with keratoconus.

We also evaluated what we call the steep square automatically minus the opposite partometer because we noticed that in some cases, like the one you can see on the left side of the screen, the I minus s when We're taking just the lower key automatically and compared to the Posterior cantometry, when we have an asymmetry between nasal and temporal, the I minus s misses it, whereas it may be more obvious when we take this when we take the steeper one. paratometry and compare it with the diametrically opposite peritometry and this is how we calculate and calculate the most pronounced K minus the opposite and it seems that in the most pronounced K minus the opposite K was statistically significantly different between normal and careful to form suspicious and character constipation, also calculated the posterior C plus Square domain, the ratio between the posterior C plus character and the keratonically anterior C plus and also this parameter was statistically significantly different between the three groups and finally we found that the most pronounced posterior curvature point was much lower , as in on the left side of the screen in the period in the suspicious and creatogon group compared to the normal group where it was more Superior, so the saturation of the most pronounced posterior creatometry was more Superior in normal patients but it was much more inferior in the ketocone aspect. and keratopo participation so there were many parameters that were different between the entire group that I am showing here the most important because it is not enough to have one parameter that is different because well, you can see here, I go back a little, you can see inthose box plots, for example, the difference is certainly significantly different, but if we take a number of this ratio, for example, it could be a normal patient, a suspected patient, a normal patient or a keratoconus, you cannot differentiate between the two and the three because it is not clinically significant, well, it is statistically significant but not clinically different, so how to predict a risk and which would be the best, the ideal test to separate between two groups of patients, is a test that can recognize completely healthy cornea and completely recognize the abnormal cornea with the clear expression between both and this is something that we cannot achieve with a single parameter in its differentiation or in the diagnosis. of suspected peritoneal because we always have some types of false negative or false positive when we put a stress path specifically if we take only one parameter as you can see here by taking only one parameter, the differentiation between normal and keratoconus station can reach high sensitivity. and specificity but the differentiation between normal keratoconus and first or early form is not reaching a very high sensitivity, specificity although it is not bad with the I minus s with 76 sensitivity and 81 specificity, it is still not enough when we clinically want to be able to differentiate between the two groups, so what we need to do is more complex statistics to combine the most important parameters and convert them into what we call a discriminant function and all together we were able to achieve a specificity of 98, which is very high and the sensitivity of 75 percent for detect those very early forms of keratoconus remember that those very early forms of keratoconus may not be accurate Congress and that's why getting a sensitivity of 75 is already very good because some of them are probably normal the cornea will never develop character spots so that once we get this, we need to validate it because we get those calculations based on a specific rule to validate it, we take 265 patients, we take 2241 normal uh topology of normal patient and 155 patients with peritoconus. and we compared these two groups and the formula that was intended to detect the early form of keratoconus was able to detect the current state with almost 100 percent sensitivity and specificity and a very high area under the zero curve, so this formula was not trained to detect the current shape.

Homes was trying to detect the early form of keratonix, but he was able to detect keratoponics with a very high sensitivity and specific specificity that comes from the effectiveness, ethics and efficiency of this form and although these are some small examples of what the software. on the old platform now, so you have to click on ectasia in your software and you will get this graph on the right with the most important parameters that you can see with the red square facing down and with the color map as long as it is green, it means which is on the normal side, as long as it's yellow it means it's more than two standard deviations from normal so it's a little bit on the suspicious side and when it's red it means it's abnormal so this cornea looks pretty acceptable and normal and on the side in when you have to uh two bars here you can press parameters when to get all those parameters which you can see here or you can press score to get the final score which is a combination of all those parameters together, so in in that case the parameter is a score of zero and you have this radar map that I will show you later that explains the different and most important parameters all together here is another example of a clear here so you can see the score. value here and also the parameters that are on the red side because it is abnormal and then the radar map showing the thinnest point I minus s K Max minus the opposite map the uh the steepest square automatic the three millimeter irregularity and the later elevation of the single spawn because those are parameters that are known to be more abnormal or to be abnormal early in the course of keratoconus, so the radar map shows them when it is green, it is normal when it is closer to yellow or red. means it's abnormal, so here's this patient's score is 9.8, which is a clear pair of two points.

Another case here where you can see it's a keratoconus patient and his score is 15.6. Here is also an interesting example of a patient who clearly has keratoconus on one side, so the score is very, very high, while the contralateral eye appears normal, with almost no major changes except the more inferior tilt and the scores, a combination of all the parameters together, is a little positive, 0.8, which means that you have to be careful and maybe not do any surgery, you know that you are not going to operate on that patient because he has keratoconus in the other eye, but if it was an isolated eye, the score would have helped you I recognize that this corner is abnormal and here on the negative side I did not discuss it either, but you have the archimetric thinning rate map shown here in the green what is the color in green are the two standard deviation from the normal patient's curve, so when something new happens, your patient's curve is not, but inside it means that you should be a little more careful specifically when the abnormality you see between 1.5 and 2 millimeters of the sinus pump and on the left it is just the documentary at different distances from the thinnest point, so that place here was clear from the full square until only that is detected by the score, and interestingly, we also had the typical measurement for that patient, so this is the same. patient here the patient's right eye while keratoconus in the other eye and if you look at the pentacon measurement you can see that the poor visualization alone is hard but not yet in the abnormal not yet not in the yellow is here the number is 1.14, while it is abnormal starting at 1.6, however, in combination with the kovis which analyzes the biomechanical properties of the cornea, you can see that the CBI here is more in yellow and the combination of the two devices, Therefore, the biomechanical analysis traces the topographical analysis.

The analysis that I was giving you is giving you a type of anomaly in that patient and the future possibility of an automated device is also to evaluate the evolution over time of a cornea and this is a patient who has keratoconus in the contralateral eye here. its measurement in 2020 is a slightly negative score minus 0.3 here it is in 2021 a little less, so it was -43 in 2020 minus 0.1 in 2021 and slightly positive in 2022.1 the young patient's date of birth in 2008, so we have to look at it, okay? I will very carefully ask you not to rub your eye and make sure that your cornea does not evolve into keratoconus and I think here is your cultural material, with a score of 13.2, so it is a clear character, in conclusion , previous.

The score combined the OCT-derived parameters of the anterior anterior curvature with the Ostein parameters of the posterior curvature and pachymetric mode, all together into a single score, a single number that appears to be effective, very effective in discriminating keratoconus and the character. Corners guy Cornell and I thank you for your foreign attention.