 Okay, good morning and thank you for being here so early and I'm very happy to be here to talk about my favorite thing Which is biomaterials that you use to manufacture intraocular lenses and the complications related to intraocular lenses So as you know, we have a laboratory on the fourth floor that I co-direct with Nick Mamelis And we have these fellows this year one of them is here the other one should be here So Nathan and Joshua and we have Biu and Tilan as the students volunteering in the lab So I would like to start by giving you just an overview of the materials that we use for the current intraocular lenses So basically you can divide materials for intraocular lenses into two major classes and you have acrylic and Silicone materials the acrylic lenses can be rigid lenses made of PMMA or they can be foldable acrylic lenses and Traditionally we divide those foldable acrylic lenses into hydrophilic and hydrophobic according to the water content and all of the silicone materials They are actually foldable lenses So here you have some examples of the rigid acrylic lenses So PMMA lenses there are mostly used to steal in developing countries But you have posterior chamber lenses that you put in the capsule of bag or in the cellcos You have anterior chamber lenses made of PMMA. You also have iris fixated intraocular lenses. They are made of PMMA So now for the foldable acrylics, let us start with the hydrophilic acrylic materials They are also known as hydrogel materials and although we have a general formula to show how they are made Actually each hydrophilic acrylic lens is made of a slightly different Copolymer of hydrophilic acrylic material. So they have different characteristics For example, the water content may range from 18% to 38% There are some others that are even higher than that their refractive index may range from 1.46 to 1.48 So again each hydrophilic acrylic lens in the market is not made of the same material There are different Copolymers in the market. So just to give you an idea the hydrophilic acrylic lenses are not very popular in the United States However, they are very popular in markets such as Europe for example and in Europe You are going to have a lot of variety of designs They are used to make these hydrophilic acrylic lenses those three here actually the center flex Hydro view and memory lens they were very available in the United States The center flex by Rainer is still is available in the United States We'll talk about the other two a little bit more later But again just to show you the huge variety of designs that are available in Europe made with this hydrogel or Hydrophilic acrylic materials. They are popular there. They are actually less expensive than hydrophobic acrylic lenses So in terms of hydrophilic acrylic lenses, maybe you heard about this Colomer material So this is a material that is made by star the company star here in the United States It's basically a hydrophilic acrylic lens with a water content of 34% with porcine collagen and this is actually used for the manufacturer of intraocular lenses for cataract surgery in plate designs in Three-piece designs, but it's also used for the manufacturer of the implantable contact lens Which is a fakie posterior chamber lens, maybe you saw some surgeries here at the moran I know that's used here and what's the principle of this Colomer material? So by having that collagen they state that the material is more biologically quiet Because the collagen has an affinity for the protein fibronectin that you see in the anterior chamber after IOL implantation and Because there will be a monolayer fibronectin on the surface of the IOL This is going to inhibit further protein deposition and then it's like the IOL is not recognized as a foreign body So in any way that's their principle There are some studies showing that the biocompatibility of this material is very good in terms of inflammatory reaction. That's really very low after Implantation now, let us move to the hydrophobic acrylic materials and again the same thing you may have some general formulas to show These materials but each hydrophobic acrylic lens in the market is actually a very different lens So for example, this is the Acrysoft material has a refractive index of 1.55 one of one of the highest which means for a given Diopteric power that will be the thinnest in trochlor lanes and you see that the water content of this hydrophobic Acrylic material is usually very low is less than 0.5 percent and later I will show you that this is changing nowadays So again, this is the Acrysoft material by Alcon here you have the sensor material That's a material that's actually used in the techniques lanes nowadays by AMO Again, you see the refractive index and you see that the water content is usually much lower than the hydrophilic acrylic materials So in what this is changing there are other hydrophobic acrylic lenses in the market with very low water content But later we'll discuss about a problem named glistening in the hydrophobic acrylic materials And there are new materials in the market for example this one this was developed by AVS But it was licensed by Bauschen Lomb and that's the material having the eternity in trochlor lanes Which is becoming popular here in this country too and it's a hydrophobic acrylic material with a water content That's almost four percent So such material prevents glistening formation That's the only IOL that the FDA actually approved as being a glistening free in trochlor lanes Later we discuss about the glistening, but there are tests in the laboratory that we can do to really Exaggerate glistening formation and we cannot see glistening with this material So the fact that you have a higher water content actually helps in that Another thing that is changing is that Traditionally you had the hydrophilic acrylic lenses packaged in a vial with solution So they are wet packet and the hydrophobic acrylic lenses would always be dry packet because the water content is so low However, this lens here is a hydrophobic acrylic lens has a slightly higher water content and is packaged in water Therefore nowadays you you don't have these traditional things anymore, but why we know that this is a hydrophobic acrylic lenses so what gives Hydrophobic character or hydrophilic is the characteristic of the surface So there are some tests like for example You put a drop of water on the surface and the way the water sits on the surface forms an angle by measuring that angle We know it's hydrophobic or hydrophilic and that what tells us that's hydrophobic material Even though the water content of the material is a bit higher Okay. Yeah, so let us get this question later when you get to the glistening because maybe with these slides I'll answer this question fully. Okay, so Let us move there now the second class of Foldable intraocular lenses is the silicone lenses. However, again the same thing not all silicone lenses are the same There are different generations of silicone materials and the earlier generation has a very low Refractive index so those lenses were much thicker than the current more modern Silicone lenses with a much higher refractive index. So they are much thinner lenses So basically what you have to understand is that within each class? You don't have just one material each lens is really made of different copolymers of that class So I would like to talk a little bit about this special silicone lens the light adjustable lens We work with this lens a lot for like 10 years and it was just approved by the FDA. So you may be seeing here These lanes and it's a special silicone lanes because it has a special Components within it that's that are named macromers. So they are not fully polymerized So you implant the lanes and then you measure the refractive power after I wear implantation And if you are not happy if you have a refractive surprise or if you want to adjust it you actually shine Near UV light on that lens and when you do that for example, if you shine in the center the Macromers, they are not polymerized. They are going to polymerize So then the others are going to move to the center and you see that there is a change in the shape of the optic So there is a change in the power of the lens. So that's very interesting because you can do a non-invasive adjustment of the power of the lens After surgery. So again, it was just approved in by the FDA But it is a silicone lens. It has to be that specific lens Nowadays you may know that we are working with another project that we use the cento second laser to change the power of the lens But that lens does not need to be a specific lens. It can be any lens So now that this light adjustable lens is approved We may have something that is actually better But in any way you need to know about this material And what else you have in the material of the intraocular lens? You do not just have the main Polymer you also have ultraviolet absorber pretty much all intraocular lenses with few exceptions They have those they are generally benzophenones or benzotriazoles So these molecules are going to protect against ultraviolet Radiation in this wavelength because the natural crystalline lens does that so as soon as you do cataract surgery And you remove the natural crystalline lens you have to have an intraocular lens that provides the same type of protection That's why they're there But you also have some lenses with special blockers You probably all saw some intraocular lenses are actually yellow and there are some in the market They are actually violet or orange in Europe There are some orange ones and basically the principle of that is that the natural crystalline lens yellows with age and This protects the retina against blue light. So the companies thought okay, maybe it's a good idea to Provide the same type of protection Within the intraocular lens so beside the UV protection these lenses have a dye They are going to prevent to block the blue light. So you see these lenses in the market and Not available in the United States But we actually work in this very interesting project and these lenses available in different markets It is a photochromic intraocular lens So this is a hydrophobic acrylic lens with a special property That for example the patient is implanted with the lens if the patient is here is dark The lens is colorless inside of the eye of the patient But then as soon as the patient goes outside and there is sunlight That lens inside of the eye of the patient very fast turns yellow Providing a blue light protection and this versa. So that was a very interesting project Unfortunately, it's not available here in the United States. You have some sunglasses that have the same property Okay, so now you have an idea about overall intraocular lenses and materials. So basically Acrylics or Silicons, but within each class you do not have the same exact material for each lens So now let us talk about some complications of intraocular lenses and you are going to see that some Complications are really mostly related to a specific class of intraocular lens So in this paper we summarize everything and we are going to start to talk about complications related to hydrophilic acrylic lenses or hydrogel So there was this complication that was very interesting This is not a lens that's available in the United States is available in Brazil and South America And if you remember the majority of hydrophilic acrylic lenses will have a water content between 18 and 38 percent This one has a water content of over 70 percent So this lens is implanted rigid when it's very small and it goes to Through a very small incision without any need of folding Once in the capsule bag starts to increase expand as a sponge So it's a very interesting trochlor lenses But then one of my colleagues there implanted these lenses in some cases where he used Tripen blue because he was doing surgery on white cataracts So the tripen blue you extend the anterior capsule and enhance Visualization for the rexes and everything and then the next day the lens was blue inside of the eye It was slightly the center and the patient was seen Hallows blue hallows everywhere So basically you have here the lens the dimensions when you insert the lens and then when it's fully hydrated You see the water content is extremely high And we did some tests and what happens is that even if you dilate the tribe If you dilute the tripen blue a lot if you have any residual Capsula dye inside of the capsule bag that lens will be able to observe and then when it expands It expands and it turns blue. So that's what happened with his case So he had a residual tripen blue there and then the lens became blue inside of the eye of the patient And there is no way to remove that from the lens So after that Complication many studies were done to evaluate the interaction of all kinds of intraocular links All kinds of intraocular links materials with different capsular dyes They are available in the market and then the authors arrived to the conclusion that it really doesn't happen very Frequently there is a possibility this could happen with hydrophilic acrylic lenses Especially if they are not fully hydrated when you put inside of the capsule bag But if you put inside of the capsule bag after dye in the lenses were put fully hydrated Then you should not have this problem of discoloration of intraocular lenses Now what's the most important problem with? Hydrophilic acrylic lenses so if you have a patient coming to you you check There is a complaint that after cataract surgery a few years later division is decreased You check the posterior capsule. There is no posterior capture of pacification or there is a Yag laser And the patient still is complaining if you look at this lit lamp You see some haze if you know is a hydrophilic acrylic lens What's the first thing you ever have to think off? Okay Joshua hard to pick on you on that one Okay, so Calcification if the patient comes there is such complaint you check this lit lamp. There is a haze You check the patient the lens he had it is a hydrophilic acrylic lens and they are available in this country You have to think about Calcification so these are the major designs in the past that had Calcification the hydro view made by Baal Shalom was available in this country These two lenses here were not available in this country, but were manufactured in this country and sent to other countries. Oh I had a problem that I lost my view here. So It's fine. I can use there in a way. So again these two Yeah, so these two here again were sent to other countries and they Opacified in large large numbers really very large numbers So with the hydro view you have like a granularity covering the surface of the lens Sometimes there are some clear marks. So you can do is to chemical stains for calcium You have the elizin red so you can directly stand the lens with the elizin red and the calcium deposits are going to turn red Or you can make slice of the intraocular lens and then is tamed by the phone cost a method And the calcium deposits we stand in black as you can see here And you can do scanning a little microscopy where you have a very high magnification of the deposit And then you select a spot and you apply a technique such as energy dispersive x-ray spectroscopy When you apply this to this area, for example It gives you like pics and those pics correlates with this composition the elemental composition of the deposits That's how we know that those deposits are precisely made of calcium and phosphate so again with the hydro view it was mostly on the surface But it was very interesting with these lanes. It was mostly within the substance of the lens So it's almost like the patient had a cataract again And you see again the the surface of the lenses here But the phone cost is actually positive inside of the lens Here we have to cut the lens to show the deposits by scanning a little microscopy And you see here the calcium and the phosphate peaks and again We had to select you section the lanes tree stain by a lizard red So with this design it was within the substance of the lanes with this design the aqua sense It was everywhere. It was on the surface. It was on the substance their huge numbers I had a friend in Brazil who implanted hundreds 100 of these lenses and 100% of them calcified. He had like lawsuits like crazy He almost had to give up his clinical practice. It was a total nightmare So later we discussed about why this is this happens memory lanes was available in this country it was made by by Seba vision at the time and we still receive once in a while lances like that here and Alan Crandall just another day Explanted a lens like that here So you may be seeing something like that in the clinics So if you have a patient with a memory lanes complaining of Decrease in visual acuity you look at this little lamp and you see granularity like that you have to think about Calcification so again, you see the scanning a little microscopy with the peaks of calcium and phosphate That's how we definitely really say it is calcification And one of the hypothesis and these we tested together with Bauchanan for the hydro view is the following So in the past the hydro view lenses were used and they are not calcifying and then suddenly the Manufactory changed the packaging and the packaging of the lens contains some silicon compounds and after that the lens started to calcify So it seems that if you have Contamination or the surface of the lens with silicon compounds or silicon elements. This is starts Calcification so we tested this for the other lenses for the memory lanes the SC 60 beov and the aqua sense because we received many in our laboratory So we performed scanning a little microscopy with the elemental composition and in all of them We actually found a higher concentration of silicon where the calcification was so that was confirmed also to be a Factor to initiate calcification for the other lenses, but this is really a multifactorial problem So you have packages with silicon compounds But that does not explain everything because if that was the only factor all of these lenses would Calcify and that's not the case So some studies show that if you use certain disco elastics in combination with those lenses, you have more calcification Other studies show that you have certain diseases with high levels of calcium phosphate. You have more Calcifications like if you have chronic breakdown of the blood aqueous barrier like in diabetes you have more Calcification but each factor alone does not explain everything So there are some factors nowadays that we still do not really fully understand But what you really have to know is this so we published this paper that showed that in the cover of Ophthalmology because the patients had memory lenses They were opacified and the ophthalmologist could not make the diagnosis of the condition So they thought oh, okay is a posterior capsule of pacification. Let us yak That's the first thing they do and actually what happens when they yag is that you have to explain to the lens in any way And it makes the explanation procedure much more complicated Then other ophthalmology said okay, it's not posterior capsule of pacification. There is something in the vitreous Let us do the tractomy. They did the tractomy and later the patient had Infection and ophthalmitis CME and this is all because they could not make the diagnosis of Calcification of the memory lens and the treatment is Explantation there there is no treatment nowadays how you make the diagnosis if you do a nice as lit lamp examination You definitely can make the diagnosis. You do not even need anything extra to figure out that and if you do nicely You can see where the deposits are on the surface anterior surface within the substance or on the posterior surface or on both So you have to pay attention to that What it is that we are seeing a lot nowadays Something really interesting. You are probably familiar with the procedures like the Mac and the sec where you have So replacement of part of the cornea and then when you put the flap You have to inject air or gas inside of the anterior chamber to keep that flap against the cornea And after these procedures if the patient was pseudo-fakie and the patient actually was implanted with a hydrophilic acrylic lens We started to observe a very specific form of Calcification that is very localized on the anterior surface subsurface of the lens just within the capsule rex's area And it's very characteristic So I would like to show you some images here all these patients had hydrophilic acrylic lenses And they had like utata and the later the surgeon decided to do the Mac or the sec and that's how they end up With these deposits. They are very localized in this round area When you checked they correspond to the opening of the pupil or of the capsule rex's and also very interesting in that form of Calcification I showed you before with the large numbers The calcification would show that like two years or more after surgery Here it may show up like few weeks after this the Mac procedure. So it's something also very Accelerated so you see all of them are very round very localized And we had this lens that was Explanted here With the capsule bag and when you do the staining you see that the deposits are there within the capsule rex's area You see the capsule rex is merging right there And if you check the IOL elsewhere, there is no calcification It's just right there and that if you think is the area where the IOL surface is in direct contact with the acres humor Right, so if you do the phone call say staining again You see the calcification localized right there on the anterior surface is not anywhere else So what happened is that some people said okay? Maybe there is direct contact between this gas and the surface of the lens that's inducing that I do not really believe So because you see some other cases where you do not see this contact between the air and that specific region For a long time So I think there is some problem some metabolic change inside of the a consumer inside of the anterior chamber Because you have the air or maybe just because you have these repeated surgeries because sometimes you do the Mac and the flap Detaches and then you have to re gas and put another bubble of air So you have these repeated procedures and maybe this is causing this specific form of Calcification however nowadays the the corneal surgeons already know that if they have a patient coming for cataract surgery It's a patient that may have some good data. They may think one day They may require the Mac or the sec or something they know that they should not put a hydrophilic acrylic lens Because the chance to get these are pacified is like 10% or a little bit higher, which is actually a lot So we had new interesting cases for example the sulco flex is a supplementary IOL is Unfortunately not available in this country is a very good lens that you can put in the sulcos on top of the lens in the back If you have a refractive surprise and that lens is in the market since many years in never ever Calcify people start doing the Mac and the sec and now we have at least four cases And that's very interesting too This lens is not available here is available in Europe is a hydrophilic acrylic lens with a hydrophobic coating The company said okay if you put a hydrophobic coating you are going to prevent the problem of calcification Sure enough it did not we have many many cases of Calcification on these lenses after the sec and the Mac And now what's interesting is that we have been receiving a lot of cases where the same pattern of Round and tear surface calcification of different hydrophilic acrylic lenses. These are different manufacturers They occur after any procedure. That's a secondary procedure Sometimes is intra vitria anti-VGF injection Sometimes is vitrach to me retinal detachment surgery or sometimes glaucoma surgery Sometimes you have gas air silicone oil sometimes you do not have any of those and still you see this specific pattern of Calcification that's why I think it's not a problem of the substance being Introduced in the anterior chamber, but it is a problem of repeated procedure Okay Silicon lenses what are the problems that we may see with silicon lenses? We had toxic anterior segment syndrome is this exaggerated inflammation that may occur after cataract surgery related to silicone lenses and oily substance floating on in the anterior chamber and in all of the cases you had silicon lenses Implanted via clear corneal incisions and the surgeon would use ointment at the end of the surgery and put an eye patch So basically you can see that these were very serious problems because it required Secondary procedures like even penetrate penetrating keratoplasty And we analyze all of these the corneals that have to be removed the IOLs and The oil inside of the anterior chamber of the patients and here you see how the lens was covered by this oily material and With different analysis like gas chromatography mass spectrometry Spectroscopy you can identify the solutions like the CSI on TV So basically turned it turned out that these were the ointments that you're using after cataract surgery So he was applying the ointment a very tight eye patch the incision would keep after surgery and the ointment was entering inside and The vehicle of these ointments the base of these ointments extremely toxic to the corneal endotelium So nowadays there is a trend to not use ointments after surgery but drops because of this problem If you have a patient with the potential retinal problem that one day may potentially require Silicon oil you should not implant a silicone lens in that patient because there is an interaction between the silicon material and The silicone oil that's irreversible and you may have a lens covered like that And you would one day have to explain these silicone lenses So in retina patients you have to select your IOL accordingly So you probably all know by now what's asteroid high losses So basically you have inside of the vitreous these bodies Very bright and basically they are composed of calcium and phosphate So in these eyes if you have a silicone lens that silicone lens actually may calcify That's the only issue related to calcification of other lenses other than what I described to you with the hydrophilic acrylic lenses It is very interesting We've described this first with very early generation silicone lenses And then with the ag laser you actually can dust those deposits out of the surface of the silicone lens It only happens on the posterior surface That's more in contact with that material and with the hydrophilic acrylic lens if you use the yag to dust off The the deposits you cannot do that but in the silicone you can however you have a vitreous full of calcified deposits So that it starts to calcify again So you would mainly have to explain the silicone lens So you see very typical only on the posterior surface you can clean with the ag laser But it starts to opacify again This is an interesting case because you had a bilateral asteroid high losses The other eye had a hydrophobic acrylic lens that lens never calcified just the silicone you have Yeah Yes, and that's very interesting because you have in many of the cases we had and First of all we check the literature. There is a permeability of the posterior capsule According to the size of the molecule and those could go through and in many of the cases we had The capsule was actually intact and then the surgeon would look the ophthalmology will look okay speciol, right? You yag immediately and then you yag and you still see these deposits there And then it gets worse because the vitreous now is in contact with the posterior surface So in many cases when They woke up for the problem the posterior capsule was initially actually intact Always on the posterior surface. So again the other eye of this patient had a hydrophobic acrylic lens The same asteroid high losses never calcified And then we thought maybe it's just the old generation silicone lenses now with the new generation that doesn't happen But sure enough we had cases with all kind of silicone lenses You can see here the different refractive index indicate each one of these lenses a different silicone material and They calcify in asteroid high losses So you have to be aware of that and we tested with the hydrophilic acrylic lenses We have hundreds Explanted we checked if those patients eventually had asteroid high losses, but there was none So it has nothing to do with that problem It is definitely a different problem in the absence of asteroid high losses the silicone lens does not calcify We had this very interesting cases from Brazil of the lenses turning white the day after the surgery And so it's very interesting. They sent to me liquid I was checking them and as they were drying the Opacification disappeared and the same thing you see here under light microscopy So as they dry the opacification disappears if you put in solution it starts again So we analyze them with many things and it turns out that they were contaminated with these molecules There are present in fumigants or Industrial clean Asians which should never be there because this is not part of the IOL manufacturer So what happens here was very interesting These lenses were sent by four of my colleagues in Brazil from different areas But before they were implanted they were all stored in one single place where There was fumigation for cockroaches So you cannot forget the IOLs may be packaged the majority of them in these Semi-permeable packages to allow sterilization by vapor So if vapor for sterilization enters the IOL You you may have other chemicals in vapor that may contaminate the IOL and that's exactly what happened So after these studies It was very clear that you have to pay attention to the conditions of storage of IOL and because of that publication Actually many companies change the packaging putting extra plastic outside because this is this was actually a real problem It was very interesting study Okay, hydrophobic acrylic lenses. What's the main issue? Glistenings and also subsurface nano glistenings. It got even worse Okay, what are glistenings? I have a major review with 20 pages if you want to read before bed So basically you have fluid field micro vacuums within the IOL when they are in an aqueous environment They may be in general up to 20 microns They are mostly described with hydrophobic acrylic lenses You actually may see them with any lens, but it's really an issue with a hydrophobic acrylic lens Not all hydrophobic acrylic lenses are the same. There is one specific material that's more problematic for that They may show up as early as one week after surgery And with the Acrysoft lens by Alcon if you really pay attention to slit lamp You always see it even in small amounts, but you always see it just to show you that they may happen with other Materials you have other lenses here with glistenings, but it's usually not an issue with other materials Incidents if if you again if you check an Acrysoft lens I believe you see glistenings in hundred percent of the cases even if very small amounts You always see they will look like this bright spots there So some studies suggest that after some time the frequency the size the density they stabilize But you have an initial period of two three years where they may keep growing So there are many classifications in the literature a ways that you check them on the slit lamp and score the amount of glistenings or You get an image from a computer from a slit lamp put in a computer and calculate the number of glistenings in a volume of the lens There are many way to grade that Why they form? What you have to know that is When you have an IOL the polymer of that IOL is complicated So you have all the polymers different components you have the UV absorbers you have cross linking agents There are many things I didn't tell you actually I just simplified but all these molecules are very complex So you have a micro voice within the polymer network And then any polymer that you put inside of water will absorb water Even the hydrophobic ones and that absorption rate is going to increase with increase in temperature so if that temperature goes above the Glastens transition temperature. That's the temperature where the material becomes flexible if it goes The temperature is rising that water absorption is just increasing. So here you have the water absorption curve for the acrysoft material So the water is there inside of polymer, but you do not see it is within a vapor form So let us say that lens is in a warm water is in equilibrium and suddenly the temperature of the environment is lowered So what's happening is that you have an excess water inside of that polymer and Suddenly it attacks from the vapor form and it's going to gather inside of these micro voids of the polymer So you suddenly have the micro voids filled with water The water refractive index is 1.33 The water the refractive index of the IOL material is always higher than that So then when you shine light you are going to have light refracted Scattered at those interfaces and that's why you see these glistening as this briny bright bright shiny thing That's what it is Once they form they continue once they form they definitely continue and then it keeps increasing. So next time you have a Change in temperature they will keep increasing So and some studies show that you just need a change of three degrees Celsius to initiate glistening is in the acrysoft material So that's a real Think and then with the acrysoft material there are some different Packages and there was an early packaging that was this up here that would make this process somehow even worse When you check the hydrophobic acrylic lenses They are made in different types of procedures like molding versus late cutting and One procedure will be worse than the other for the glistening information if the patient had diabetes glaucoma It seems that that will make glistening formation also worse But here is just is very complicated just to show you some of the hydrophobic acrylic materials in the market Each one of them has a different tendency to glistening formation The most problematic one is really the acrysoft materials the one that mostly people noted under sleet lamp That there is something going on in the update So Again, I want to highlight the fact that there are new materials with a higher water content They are still hydrophobic really, but because they have this water equilibrium. They do not form glistening so the temperature imbalance in those materials does not influence anything because they are ready in equilibrium with a higher water content They're glistening free. So this was the first material they invista but nowadays in Europe you have at least two more and Alcon is already launched in the Europe during the last ESRS a new lens named Clarion. You may be seeing this soon So Clarion is a hydrophobic acrylic lens made by Alcon with a slightly higher water content And it seems to be glistening free too. I don't know if they will continue with the acrysoft or not But in in the near future you may be seeing a shift there because the acrysoft is still the most implanted lens in the world So they may discontinue that and start with the Clarion. I don't know exactly the plan, but they address that So does this have an effect on vision function? It really depends on who you are asking the question So I revealed the literature in some studies you see that even if you induce exaggerated amount of glistenings They would not impact visual function Some studies show that they do impact contrast sensitivity even visual acuity Many studies will clearly say that they do not it's a very controversial matter But in any way there is a potential at least for impacting the visual function But in some studies, I mean like this case that I published you have some exaggerated Amounts of glistening. So these are not only a lot. They were huge and actually this patient had the retinal issues So he was not complaining of decreasing visual acuity But the ophthalmologist could not do a nice retinal examination of this patient because of the glistening in this acrysoft So I got these lanes and I put in water and compared with a control So you put in water and you change the temperature. That's how you form glistenings in the lab is very easy And this is what you get with the control 20 microns. This here is like 200 300 microns So that was a total aberration. I never saw this, but it was definitely exaggerated But now the aqua soft material has another problem. That's called subsurface nano glistenings and what it is that this is a lens that was Explanted from a cadaver eye. This is a control both a crystal lenses inside of water The light is coming from above. They are exactly the same position Here the only thing I changed to take this photograph is that the light is now coming from both sides And you see that one is totally white and the other one is not So what is that this is done by the subsurface nano glistenings? So the glistenings are here inside of the optic of the lanes Vacuels filled with fluid the subsurface nano glistenings are just very small molecules on the subsurface Of the lanes. This is also an issue with the aqua soft material. It happens with other lenses, but not up to this extent When you do shine fluke photography, you can see this and actually measure the brightness of that So you can actually quantify that so that's that lanes. That's the control you barely see the IOL And we did many studies to try to show what's the impact of the subsurface nano glistenings on the visual function of the patient we measure light scattering light Transmittance and we can see that they grow with time Some clinical studies show that the aqua soft lanes may have increasing rates of subsurface nano glistenings up to 10 years So that is really complicated So that's an aqua soft lanes again a single piece and here you have the shine fluke photography of that lanes with a lot of light Scattering and here is the control So even though you have a lot of backlight scattering when you measure the light Transmission between these two lenses. They were just the same This is just to say that if you consider subsurface nano glistenings alone Even very high levels are not likely to impact the visual function However, the problem is that if you have an aqua soft lanes, you may have both issues You may have glistenings and subsurface nano glistenings and that gets complicated So this is a single-piece lanes without the blue blocker and again the same thing a lot of backlight scattering But the light transmission was pretty much the same Now they may stay Separate issues they may start simultaneously with time you start both Growing you may have lenses with one or the other More prominent feature. So it doesn't seem they are completely independent. They the Subsurface nano glistenings are not dependent changing temperature also It seems to be a characteristic of the surface of the lanes So who I am talking about that is very interesting because when you are doing a slit lamp of these patients, you know how you can Change the angle of the light, right? And I don't know how many males I get from surgeons all around the world of tomology saying, okay I have an aqua soft lanes is hydrophobic acrylic. I am sure it's calcified and then I tell them, okay Read this paper because I am sure it's not because what happens is that if you put the light in an angle This becomes so white that it almost really looked like a calcification And then you get all these people panicking I have this hydrophobic acrylic lanes You told me you'll never calcify and I'm sure it's calcified and sure enough is not so as there are so many Hydrophobic acrylic lanes in the market here, especially at resolve you have to be aware of that because one day you may be in this little lamp and you Angle your light just right and you're going to see this white thing And you are going to be really surprised But usually the patient is not complaining much which is very interesting because it looks absolutely horrible Okay, so and then the next class of material going to discuss is the PMMA rigid lenses There's no flake degeneration That used to happen with old PMMA lenses Manufacturing the 80s or 90s by injection molding. It does not really happen with modern lenses I mean, I really could not trace back any modern lenses everything I could we could receive here and analyze we trace back to this era and to this procedure So it's very gradual sometimes it takes 10 to 20 years to be really Apacified and then at that point you really have an issue with the vision function and for example here So once in a while believe me or not, we still receive things like that And what's interesting is that you are noticing that there is no lesion and the periphery of the optics mostly the center Right because the periphery of the optic is covered by the iris and it's always like that So dr. Apple name is no flake because they the individual lesion may look like is no flake So the explanation of this is not always necessary because it may take 20 years for this to be visually significant but it's good if you check that you see the difference with glistenings because the Fluid-Fueled vacuums are very very different So what is that by at that time with that type of procedure of manufacture? They had to use a molecule to initiate polymerization And in some cases there was a nexus of this molecule and with time in that region of the optic You have UV light that is coming through the periphery is usually protected by the iris And what you had is liberation of gas inside of the IOL and was like cracking the IOL So what what you see is actually cracking inside of the optic and again is pairing the periphery of the lens so You have to make a difference because even in dry state you see there's no flakes If you dry an IOL with glistenings you do not see any glistenings because it's all based on the water thing However in these areas where you have snowflake cracks snowflake lesions you have excess water that may be Cumulated there making it clinically significant So again what we learned here is that there are different IOL materials and there are different factors That may be sometimes related to the patient like you have a DMACC procedure IOL manufacturer You have this excess molecules in this impolymerization the IOL storage You remember the case in Brazil with the fumigation adjuvants this you know think that with some viscoelastic You may have more classification than others There are many factors that may be involved in a process of a pacification of intraocular lengths Disopacification may be absurd fast after surgery or many many years after surgery So for some complications you also have not only the influence of the material but sometimes of the design I do not have time to show here But if you have an IOL that's specifically made for the capsule bag like the single-piece lenses if you put that lens in the So because you have a whole new Series of complications because that design is not adapted for that site But we focus today on the complications of the materials So because every year in the market there are so many new IOLs We have to be always vigilant and there are many new materials coming up Especially with this new thinking that you can have hydrophobic acrylic materials with higher water content to be Glistenings free is a huge number of new materials coming up And we have to pay attention because maybe in a few years We are going to be seeing complications that we never saw before and we have the privilege to receive in the lab These lenses that are ex-planted from all over the world and sometimes we are really surprised with what we see But it's always very interesting. Thank you very much any other question. Did I answer your question about the glistenings? Sure That is a very good question because It depends on your incision if it's going to gape or not But if you put the glue and you prevent that I would assume not But I think the easiest thing is really to avoid ointment, which I think in this country is not that common That was all from Canada. It was very interesting from different sites But it seems up there at that time It was almost like a standard of operation procedures to finalize the cataract surgery put ointment and the tie-tie patch And it came from different sites in Canada. They change because of this problem So I don't think it's very common here. I don't think here is the moran. Nobody we use in our rabbits by the way But yeah, I don't think you use in your patients But it's a real problem the component the base component of this ointment is extremely toxic for the endotelium The majority of the cases require corneal grafts Okay, so now you have just to take home message and I think in your tests you have these questions Hydrophilic acrylic lens is what's the most important issue? Calcification hydrophobic acrylic glistenings PMMA snowflake degeneration Can a silicone lens calcify? Yes in eyes with asteroid hyalurzes. I think those are part of some questions You have your test so keep that in mind Thank you. It seems I will see you tomorrow