Lecture: MIGS and Evolving Non-traditional Glaucoma Treatment Options For the Anterior Segment Surgeon

Due to the high frequency of cataracts and glaucoma coexisting, the anterior segment surgeon has expanding options to treat mild to moderate glaucoma. During this lecture, we discuss and review surgical videos of various Minimally Invasive Glaucoma Surgery (MIGS) procedures. New and evolving technology for implantable drug delivery systems are also discussed. This lecture will benefit any anterior segment surgeons seeking to learn more about the existing and evolving interventional treatment options for mild to moderate glaucoma. (Level: All)

Lecturer: Dr. Kevin Barber, Ophthalmologist, Advanced Center for Eyecare Global, USA


DR. BARBER: Thank you. Thank you, thank you. All right. Happy Friday, everyone. Good day. Excited to be here on the Friday edition of the Orbis Cybersight. And what an exciting way to get our weekend started together by talking about a very rapidly-evolving and growing area of anterior segment surgery. So, let me go ahead and get my screen share going.
And today we’re gonna spend the next 45 minutes or so talking about MIGS, or minimally invasive glaucoma surgery, and evolving non-traditional glaucoma treatment options for the anterior segment surgeon. My name is Kevin Barber, I am anterior segment surgery from the East Coast of the United States, from Orlando, Florida, and the President of Advanced Center for Eyecare Global. These are my relevant disclosures, I’m a consultant for Alcon and Iantrek, and on clinical trials. So, the learning objectives for the next 45 minutes or what this lecture will be about is a comprehensive, as possible, review of MIGS and drug delivery technologies that are either currently available or will be coming available to the anterior segment surgeon in the near future. Now, this in full disclosure is coming from my perspective as a practitioner in the United States and I’m fully acknowledging that MIGS is new enough that it hasn’t been fully globalized. So, I understand there might be MIGS procedures available in other parts of the world that we don’t have here in the US or Europe. I’ve tried as best as possible to include every technology that I’m aware of. And I’m also acknowledging that some of the technology that we have in the US is just not available in other parts of the world. But I think the point of this lecture is to give a comprehensive review just so you’re aware of what’s available now and what’s coming. Because I do believe that this is a — the future way for many anterior segment surgeons. This lecture will not be an exhaustive talk on data or outcomes. There’s not a lot of data on the comparison of MIGS or drug delivery devices. That would be several more hours of lectures together. So, we’re not gonna do a deep dive into all things MIGS, but more staying on the superficial level. I’m gonna show a lot of surgical videos just so you can get a glimpse of what the MIGS space looks like now. If we think about traditional glaucoma treatment, as you all know, we start with eye drops. If eye drops are not sufficient, oftentimes if there’s availability, we’ll go to an SLT laser. And then from there, we would jump to incisional surgery, trabeculectomy, tubes. The MIGS and drug delivery space is attempting to bridge the gap between the conservative treatment of drops and SLT and more invasive surgeries like tubes and trabs. We’re talking about patients with moderate to mild glaucoma. Most of which are undergoing cataract surgery. A lot of MIGS is being tied to cataract surgery. Although it can be done independently of cataract surgery. But it’s trying to take mild to moderate glaucoma patients and lower the risk of them going on to needing more invasive surgeries. This MIGS and drug delivery space has been rapidly growing. You know, 20 years ago there was almost nothing in this area. And today we’re gonna talk about 18 different technologies. So, we will be moving somewhat fast. So, let’s just review our anatomy. We’re talking about mostly the trabecular outflow system is where the majority of MIGS has been centered thus far. So, we’re talking about affecting either the trabecular meshwork or Schlemms canal. And we’re looking at the space between the ciliary body and the sclera, that’s a newer and a rapidly-evolving area for MIGS. And then there’s also the sub-conjunctival space, the traditional trabeculectomy space. But there’s newer devices helping to make that a safer procedure. And then with drug delivery, we’re talking — it’s a all in the anterior chamber or it’s intracapsular. So, drug delivery is a smaller — a smaller top take we’ll talk about. So, we’ll start with that first. When Amy talking about drug delivery, I’m talking about intraocular sustained release drug delivery. Why would we use that? What are its advantages? As you know, compliance is one of the biggest issues with glaucoma treatment. Patients, no matter where they are in the world have difficulty being compliant with topical drop therapy. Sometimes the drops are not affordable. There’s memory issues. There’s dexterity issues. You know, did the drop get in the eye or did it bounce off the cheek? There’s different absorption rates. There’s so many complex factors that go into drops and getting the correct amount of drug to the target tissue. So, when we use drug delivery — so, we take the drug and we put it inside the eye — that ensures adequate delivery of the medication to the target tissue. Now, potentially — not now — but my hope in the future is that this will be more affordable for patients. So, imagine patients needing to come in once every few years to receive an intraocular drug delivery system instead of having to take drops multiple times a day every day of their life. Drug delivery can also reduce ocular surface disease. As you know, that’s a big deal when you have patients on all of these drops, almost all of them get dry eye, they get so much disruption of their ocular surface. All of that’s negated with drug delivery. And it can also reduce other side effects, for instance, the skin discoloration that we commonly see with prostaglandin analogs. There are currently three drug delivery systems I’m aware of. In the anterior claim we are, iDose, and Durysta and intracapsular, there’s Spyglass. Start with iDose or iDose TR. This is an intracameral implant. Just approved in the United States. This is groundbreaking technology. Now you can put travoprost in the eye for 24/7, continuous release. You can see it’s about 1.8 millimeters in length, half a millimeter in diameter. Filled in the container and then a filter that controls the rate at which the drug is being released into the eye. It has a simple, but elegant insertion system. I’m not gonna show a lot of data today. But this just typically shows that the amount of travoprost lasts up to 20 months. We saw 18 to 24 months of efficacy. Let’s see what it looks like. Here is an eye dose. With all MIGS and drug delivery, it’s an important skill, you have to have a good view. Here the patient is looking to the side, a goniolens on the eye and aiming right for the trabecular meshwork. Take that barb and puncture through the meshwork into the wall. The distal side of the Sclemms canal. And anchor in the sclera. Here I am tapping it to make sure that the fixation is secure and that it’s not going to move or to migrate. I’m making sure that it’s equally — it’s not touching the eye arise or it’s not touching the corneal endothelium. Then we’re typically doing this just with some small amount of viscoelastic in the eye. This can be used in both phakic or pseudophakic patients. So, then we’ll go in with a little BSS solution and we’ll irrigate out the BSS. And as I’m irrigating out the — the viscoelastic, I’m sorry — as I’m irrigating out the viscoelastic, I’m blowing it around the eye dose just to make sure it’s not working. You can see it there without the gonioscopy view. New technology that I think we will see fairly rapid expansion into the market place. The next one was Durysta, brought to the market by Allergan, it’s a Bimatoprost intracameral implant. And sustained release, unless we remove it, it stay there is. And it’s sustained reduction of intraocular pressure. It’s very small. 1 millimeter by 07.2 millimeters in diameter. And it’s supplied with a pre-loaded applicator with a 28-gauge needle. And this can actually be done at the slit lamp or in the operating room under operating microscope. I would recommend under an operating microscope until you get adept at this. Make a clear corneal incision with the 28-gauge needle. You make about a millimeter-long tunnel and then you simply release the button, injecting the Durysta implant into the anterior chamber. This will fall down into the inferior angle and it releases drug for the next 6 to 12 months. And again, because the medication is inside the eye, we see really good results because we’re not having to worry about absorption through the cornea or the ocular surface. Okay., the final drug delivery device is being brought to the market by Spyglass. Now, this is not been released yet, not commercialized. This is still in development. But I had to talk about it because I think this has such promising ideas to it. So, this be the world’s first IOL mounted controlled release drug delivery platform. They’re targeting to get 3 years of drug delivery of bimatoprost. To treat glaucoma patients undergoing cataract surgery. A lot of patients undergoing cataract surgery that also have glaucoma. Spyglass has several drugs in development for this unique system. Go back and look, these little pads can be filled with different medications. They are clipped on to the happen ticks of the IOL and placed into the intracapsular bag during cataract surgery. So, bimatoprost, starting to treat patients with glaucoma. But there’s a chance to put the steroid and nonsteroidal medication after cataract, and patients with chronic uveitis, and even wet macular degeneration can be used. So, this is in my opinion an exciting and rapidly-developing area for anterior segment surgeons. I think that — or my hope is that over the next couple of decades we’re gonna see a large transition into more drug delivery systems. So, let’s do our first poll question. As more technology in drug delivery is develops, how significantly will these drug delivery change the future management of glaucoma? This is just an opinion. Do you think it’s a major change and the drug delivery systems will actually replace drops. Do you think this will be a second tier treatment after drops. Do you think this will be considered equal to drops, patients are given the option? Or do you think this is not going to really affect our glaucoma management at all? I’ll give you all a few moments to log in your answers.
Okay. Interesting. So, we have 48% — so, almost half of you — think that this is going to be a major change in our treatment paradigms. Only 2% thinks that this will not change our glaucoma management. And about 35% think that this will be a second tier treatment. So, I think — I kind of agree with the majority of you. I don’t think we’re there yet. But I think as this technology evolves, it’s going to be a really effective way for anterior segment surgeons and practitioners to treat glaucoma. And I think we’ll be able to offer our patients better results. Okay. So, we have completed drug delivery. Now we’re gonna dive into this rapidly-expanding space and world of MIGS, a minimally invasive glaucoma surgery. So, if I did this talk 20 years ago, this slide would be blank. There wasn’t anything there. If I do this talk a year from now, this slide will probably be a lot busier. Though right now there are 15 different procedures for MIGS that I would like to present today. We’ll briefly present each one. But there’s so many that are continuing to come out. There’s a lot of research here. This is a very rapidly-expanding area. I think that the community, the anterior segment, the glaucoma and the ophthalmology community has realized the real value of MIGS. So, we’ll talk about MIGS from the perspective of ones that treat the trabecular meshwork, ones that are subconjunctival. And ones that are the supra choroidal space. There’s ways to treat. With MIGS in the trabecular meshwork, goniotomies, a hook blade or GATT. You have canaloplasty, trabeculotomy, and then the stint. Before we dive in, one more poll question. I would like to know my audience a little bit. How does MIGS currently fit into your practice? Are you someone who commonly uses MIGS procedures already? Are you rarely using MIGS procedures? Are you considering using MIGS procedures, but still gathering information, so you haven’t started yet? Or you have no plans to use MIGS. And I’ll give you a few moments.
Okay. A really nice distribution here. So, 20%, 19% saying that you’re already using MIGS. About 17% saying you’re rarely doing it. 50% — so, half of you are saying that you’re still considering it and you’re in the information gathering stage. That’s great. I’m glad you’re here today and I hope this talk will help you in your journey discovering how to implement MIGS into your practice. And we have 14% that say they have no plans to use MIGS. So, I think this is really helpful information. Okay. So, next is the Kahook dual blade. This is one of the earlier MIGS procedures that came out. This is one that’s very commonly used. Developed by Malik Kahook and brought to the market by new world medical. We can see it’s simple and elegant. It has a dual cutting blade here. As you advance the Kahook blade through the trabecular meshwork, you get a bright wide stripe, which is actually the backside of Schlemms canal, the meshwork and the backside of Schlemms canal. This is one I did recently. The gonioscopy is everything. The patient looks away, tilt the microscope, zoom in. And you can see how easily it slides along. And as you’re sliding or advancing it, you’re just removing some of the — or a strip of the trabecular meshwork. I go counterclockwise first and then back and clockwise. What that does is that amputates the strip of the trabecular meshwork. If you look right here, you can see that bright white stripe. That’s really what you’re looking for. Is that window that you’ve now created into a Schlemms canal. And this is technically a simple procedure that’s easy to learn how to do. I think the hardest part is just learning how to get a good gonioscopy view. You can see that white strip there. Now, you can in low-income settings, this has been reported to be done with just a 27-gauge needle. A bent needle. If you’re in a setting that economically does not allow for or it’s not affordable to buy these Kahook plates. I think they do a better job because of their unique design, however, this, you know, there are reports and a little bit of data out there of using 27-gauge bent needles. Okay. Let’s talk about the OMNI now. So, the OMNI combines two different procedures. It first does a canaloplasty. Insert into Schlemms canal, insert at 180 degrees and as you retract, it is viscoelastic. And that dilates the canal and the channel. That’s the definition of a canaloplasty. And then it also with the same device can do a trabeculotomy. Same device into Schlemms canal and remove it, out of the anterior chamber. It removes 180 degrees of the trabecular meshwork. This is what the device looks like. Very simple, ergonomically designed, place the viscoelastic in the reservoir in the handle. And let’s take a look at a case here. We’re putting some viscoelastic on the cornea to give us a good gonioscopy view. This was combined, I did the fake emulsification, and at the end of the procedure, have the patient look away from me. And you can see in this case the patient is looking to the left. This is the cannula here. I always look at the cannula and advance the catheter to make sure it’s going into the eye. And put the end on. You can see the pointed tip, you puncture the trabecular meshwork and then advance the catheter. If you watch closely, the catheter nicely expands Schlemms canal. You can see the trabecular meshwork in Schlemms canal is narrow, but it’s being expanded as it’s advanced. And I’m going to advance 180 degrees, we can only see a couple of clock hours here. But it’s advancing 180 degrees, and retracting it back towards the injector. And viscoelastic is being injected so the canaloplasty is being performed. It’s being retracted, not all the way, but back to the starting point. And now I’m just gonna advance it again. There it is, there’s the end. Now I’m advancing it again. And then I’m just gonna simply pull it out and by doing that, we’re doing the trabeculotomy portion and removing it. You can treat the same 180 degrees with the canaloplasty and the trabeculotomy, or you can do one and flip it around and do 180 degrees for the other. Now, each one of these MIGS devices has a nice trial associated with it. The Gemini study was the one associated with the OMNI. The reason I’m showing this one, it’s a classic representation of a lot of these MIGS devices. We’re seeing pressures at baseline before the procedure somewhere in the mid-20s and then we’re usually somewhere in the mid to high teens afterwards. And there’s subtle differences to each of these MIGS devices. But the data all looks somewhat similar to that in that we do see a nice reduction in pressure. Sometimes they’re compared to cataract surgery alone, sometimes they’re compared to medications. Now let’s talk about the T-Rex. The T-Rex is similar in that it’s doing a goniotomy or trabeculotomy. It has two cutting edges which is different. One cutting edge that will remove the trabecular meshwork. And then the distal portion of Schlemms canal is also being opened up because theoretically there’s resistance there as well. Now, this device has not been commercialized yet. It’s still being refined. This is one of the earlier models. But you can see here, a very similar cannula to some of the other MIGS devices. And you can see the wire retracted here. Goes in and out very nicely. And so, again, this one’s going to do a cut on the proximal side, so, on the trabecular meshwork side just like a Kahook blade would do. And we can’t see what’s happening behind the catheter. But again, get a really nice gonioscopy view. The tip of the cannula is used to puncture through trabecular meshwork. We then advance the catheter here, and it’s cutting the trabecular meshwork. You can see a little bit of heme, which is very common especially because we’re also incising the distal portion of Schlemms canal. So, be on the lookout for this one. It’s gonna be commercialized in the near future. And it will offer some unique advantages. A brand new one on the market is called the SION. Just brought out by Sight Sciences. It looks similar to the Kahook blade. It’s a blunt stip, not a sharp tip. Being advertised as a softer, more gentle device. And also has this window here so you can see the trabecular meshwork being removed as you do the procedure. Now, this might be one of the most important slides if having access to a lot of these MIGS devices is difficult. If you’re in a low-income area. Then you need to become really familiar with GATT. Gonioscopy assisted transluminal trabeculotomy. You’re only using sutures. You melt the tip of it, and insert into the anterior chamber through an incision. And you need the microforceps. I don’t have a video, but go to i Wiki.org or YouTube, you can find lots of great videos on GATT. But you’re going to cannulate Schlemms canal with the suture. You’re gonna thread it all the way around, and then you essentially pull it out. Similar to what we saw with the OMNI, you pull the catheter out, it removes the trabecular meshwork. Same thing, but with a low cost 5-0 proline suture. This is one of the best options for low-income countries or countries that don’t have access to some of these more expensive or cost-prohibitive MIGS devices. So, definitely write GA TT down if you’re not familiar with it. Do a little research on it. And I think this is a great place to start your MIGS journey if you’re wanting to offer this in low-income settings.
Okay. You’re all probably familiar with Glaukos, one of the leaders in MIGS, they brought the iStent on the left. And it brought it into the canal, the lumen was in the anterior chamber. It’s now evolved and we’re now at the iStent infinite. It looks quite different from the original iStent. This is in the anterior chamber that we would see from the gonioscopy view. This is in the Schlemms canal. And we’re actually placing three of these. This is what the injector looks like. The injector works really well. I want to point out here on the far right, insert the trocar, that trocar is really important when you’re learning how to insert iStent infinites, that trocar is what the device rests on. And you need to have that trocar perfectly in the center. You don’t want it biased off to one side. That can cause resistance and prevent the device from being injected properly into the trabecular meshwork. Let’s take a look at one of these. Again, this is a very simple procedure. It’s a procedure that can be learned quickly. So, this one is being combined with cataract surgery as now iStent in the itself can be done as a standalone procedure. But still most are being done with cataract surgery. Make sure we get a good gonioscopy view again, have the patient look away from the surgeon, tilt the microscope. In the center, you can see that trocar. We’ve got a moving patient here. So, a little bit of a challenge to get the view. But then you take that trocar, puncture into the trabecular meshwork, indent lightly as you see here, and then you press the button. You hold the button and then back out. And when you back out, the iStent is placed very nicely. Then you want to move down one to two clock hours. Ideally a full two clock hours. I didn’t get that here, but repeat the procedure. And see how easily the device goes in, puncture through the trabecular meshwork, indent lightly, make sure the trocar is in the center, press the button, hold the button, release and you have three iStent infinites adequately placed. And what we’ve seen is the IOP reduction benefit is improved with the more iStents. And that makes sense, right? We’re accessing more collector channels. If you can get four to five to six clock hours covered with three different iStents, we’re going to get better IOP reduction. All right. The next Microstent is the Hydrus, also a well known device. Developed by Ivantis and acquired by Alcon. This is an 8 millimeter-long Microstent. Made out of a form of very flexible metal. And it covers about three clock hours of the trabecular meshwork. Now, what was interesting about the study, the FDA clinical trial they did with the Hydrus, they took patients with mild to moderate glaucoma. Some had cataract surgery alone and some received the Hydrus. When they followed them for five years, they realized the number of patients with mild to moderate glaucoma that went on to need a more advanced surgery like a trabeculectomy or a tube shunt was cut by more than half. That’s good news. We’re trying to control or treat moderate to mild glaucoma at an earlier time point with more effectiveness in hopes that fewer patients need to go on to incisional or more invasive glaucoma surgery. So, let’s take a look at a Hydrus implantation. So, you can see this cannula looks very similar to some of the other ones you’ve seen. You’re going to take the tip that have cannula after you’ve achieved your gonioscopy view and roll or slide this wheel forward which just advances the Hydrus into Schlemms canal. You can see there’s very little resistance. It slides in very easily. Now, you’ll notice here that I’ve got about 3 millimeters of the device sticking out, we don’t want to leave it, that can rub on the iris, that can cause a syndrome. And slide it in more, and see how easily it goes in. Very atraumatic installation of this device. And you can titrate how far you go down and you see a little bit of blood reflexing there from the collector channels. And again, an easy — an easy procedure to do and great pressure reduction with that device. All right. Now we’re gonna talk about one that’s just a little bit different. So, this is an ELT, an Excimer Laser Trabeculostomy. This is approved and used in Europe. We are just finishing the FDA clinical trials in the US. It uses a 3.8 nanometer laser. And we’re essentially creating little open spots or trabeculostomy spots, and by the laser making the spots similar to an SLT, hopefully less inflammation and the otomies will stay open longer. So, this is a — a video from Dr. Sarkisian during the trial. A lot of the great concepts, a great gonioscopy view. This is a small, thin probe that’s easy to handle. The idea is to advance the probe over to make contact with the trabecular meshwork. Now, the surgeon has a foot pedal that’s controlling the laser. And the laser has a defined duration. When you step on the foot pedal, it delivers just under a second of laser ablation and then it stops. So, the surgeon doesn’t have to control that with the foot pedal. Just steps on the foot pedal, there you see the laser emission. You then move over just a couple of spot sizes away and you do another one. And you’re gonna continue to do ten of these and covering usually about four to five clock hours. Data will be released on this in the not-too-distant future. So, it will be interesting to see how this works its way into the MIGS space. This is just a gonioscopy view post operatively of some of the goniotomy spots you can see in the trabecular meshwork. Next device I’ll mention briefly, Ab interno, but it’s similar to the micro catheter, and the neat thing about in is it has an illuminated end, you can watch the catheter go around. And the unique thing, it treats 360 degrees. If you remember the OMNI treated 180 degrees, this does 360 degrees, as you’re retracting the catheter, you’re injecting viscoelastic, and this allows you to titrate how much you want to inject. This is Streamline, released by New World Medical. And this is on the right. You can see the blue tip. This blue tip is advanced and pressed against the trabecular meshwork. When you press the button, this metal device is actually injected in through the trabecular meshwork, and viscoelastic is injected in both directions. This is a gonioscopy view of the device, I don’t have the video. But shows the device being pressed against the trabecular meshwork and it’s injecting viscoelastic here. And you can do multiple entry points. This allows you to titrate how much canaloplasty you want to do. Okay. We have quickly covers the trabecular meshwork MIGS devices. Now we will transition quickly into the subconjunctival. There’s two, Preserflo and the Xen. The Preserflo not available in the United States, but is available in other countries. It’s a 7 micron lumen tube that’s approximately 8.5 millimeters long. And it is used for — so, think about doing a trab. You’re going under the conjunctiva, but use the tube and inject it into the anterior chamber. This is like a refinement of a trab this is going to control the amount of aqueous that’s going to be released. It’s going to help prevent things like hypotony. Instead of a Kelly punch and a large hole that makes aqueous and trying to titrate that with the scleral flap. This tube is watching the amount of outflow. And the lumen is not occluded by endothelial or inflammatory cells. But small enough to control or cause enough flow resistance to prevent things like hypotony. The Xen gel, very similar concept. The unique thing about the Xen, implanted at interna, it’s on the bottom image, implanted through the anterior chamber, or externa, in the conjunctival space. But the same thing by causing the amount of control of fluid coming out. And use it and have a bleb that’s very similar to a trab. We’re trying to reduce some of the complications of a trab, making it a safer procedure. Which is why it’s oftentimes rolled into the MIGS category. Okay. Final category of the MIGS procedures. This is accessing the suprachoroidal space. Three devices, the AlloFlo, the MINIject and the Ciliatech. You might remember the Cypass that was brought to the market, but in patients there was endothelial loss because it might have been too far into the anterior chamber. Therefore, it was removes from the market. And lots of companies have been hesitant to go back into that sutra choroidal space. But they’re not abandoning the idea, just refine it and make it safer. Accessing the uveoscleral outflow is a great idea because that’s where the prostaglandins act. There’s actually potential for more aqueous drainage through the pathway compared to the trabecular pathway. There’s a lot of potential that’s untapped or unrealized. The first is called AlloFlo by Iantrek. They have a cyclopen that creates a small dialysis. And insert this allograft of bio tissue, and holds open the cyclodialysis, and scleral reinforces it and allows the aqueous to flow out and has access to the uveoscleral outflow. This is what the pen looks like. A soft tip that is adept at making a cyclodialysis. And implants the bio tissue. The advantage to the bio tissue, in theory, it’s anti-inflammatory. It’s scleral tissue. It’s in the piece of metal. It’s not seen as much of a foreign thing. Hopefully there’s gonna be less fibrosis and inflammation, rendering better long-term results. This is one of the procedures, good gonioscopy, and I’m going to use the catheter to tease away the root to look at the body between the — and the sclera. And then advance the catheter. I’m going then remove the catheter and leave the piece of allograft, the bio tissue, the sclera is left in the cyclodialysis just like that. So, here I am tapping it into place. So, obviously, we don’t want this protruding into the anterior chamber where it can be touching the endothelial cells. Always thinking about endothelial cell preservation in any MIGS procedure that we do. So, there’s the first one. Now take the second cyclopen with the second piece of tissue, this is donor scleral tissue. I’m going to just enlarge that cyclodialysis by another millimeter or two. And then insert the allograft tissue into that uveoscleral space, that supra choroidal space. It’s really protruding out. 2 millimeters of it. I’m going to lightly tap it down, back down into place. We don’t see these things migrate. We have great OCT I means over time. They really stay right where they put them. And they do hold open this cyclodialysis. And so, now that space in between the two pieces of sclera is going to remain open and allow aqueous to have access to the uveoscleral space. Okay. We are almost there. So, hang in there with me. The MINIject is being developed by a company call the iSTAR. It’s been approved I believe in Europe and undergoing FDA trials in the US. Similar to the procedure I just showed you, I don’t have a surgical video of this. But this implant, this MINIject has anti-fibrotic and anti-inflammatory properties. That’s important. That’s where a lot of the MIGS thinking is developing to, more towards biocompatible tissues and materials as opposed to metallic or metal. And this is very porous. You insert it into the exact same space that I showed you in the uveoscleral space in between the anterior body and the sclera. This is going to be exciting to see the results of this and watch this enter the global marketplace. This is the last — the last device I’ll briefly mention. This is called Ciliatech. Not approved in the US. So, I don’t have surgical videos of this. This has been done in Europe. That is very unique and brilliant idea, I think. So, what this is called, a cilio-scleral interposition. You don’t have to access the anterior chamber. Take boundary the conjunctiva, and make a 2.5 millimeter scleral incision and insert the device in the bottom right underneath the sclera. It sits underneath the sclera, but on top of the ciliary body. It’s creating space and allows fluid to titrate through that space with less resistance. So, you’re still opening up or accessing the uveoscleral pathway, but not having to access the anterior chamber. So, very possibly, there’s going to be some safety benefits to this. So, again, let’s keep our eyes open and see how this — see what the studies and the data are gonna show. But I think a lot of — a lot of surgeons are anxiously awaiting the data for this one. Okay. We are 43 minutes in and we have covered very quickly 18 different MIGS procedures plus the drug delivery. And so, that was a quick whirlwind there. So, now I would like to do a couple of poll questions and then we’ll enter into a few minutes of question and answer. So, first follow question: Which type of MIGS procedure is your procedure of choice? So, if you’re already doing MIGS, tell us what your procedure of choice is. If you’re not doing — if you’re not doing MIGS, then if you’re anticipating starting, tell us what you think you’ll start with. I’ll give you just a few minutes for that.
Okay. The 38% say goniotomy. Or actually tied. So, we have a tie here, 38% goniotomy and 38% sub conjunctival. The supra choroidal and canaloplasty. And I think a lot of you in the glaucoma space or glaucoma specialist, the subconjunctival are comfortable. Maybe for the cataract surgeon, that’s a little bit less comfortable. They migrate towards the canaloplasty, the goniotomy and the micro stints. The supra choroidal space. It’s going to be interesting, if I do this talk in a couple of years, it wouldn’t surprise me if that’s the largest growing one as we kind of learn how to safely do that procedure. And offer — offer just another way to treat glaucoma. Okay. And then I think we have one more… there we go. One more question. This is the last poll question. What obstacles keep you from fully utilizing MIGS procedures in your practice now? So, this is obviously a question that’s globally-oriented. Is it insufficient surgical training? Is it mostly economic barriers, you just can’t get the MIGS procedures affordably in your area of the world. Are you just not convinced that MIGS is a safe or effective procedure yet? Or are MIGS devices just not available in your country or practice setting. Tell me, what are the major obstacles for you doing MIGS procedures in your practice?
Okay. So, the results are in. And 50% say that it’s insufficient surgical training. Okay. Great. So, that’s really — that’s really helpful information. So, I think that’s a challenge to the global ophthalmology community to just start to provide more access. And maybe industry can get involved. But more access to training. It certainly is a skill that needs to be developed. But it’s not, you know, it’s not that difficult. It just takes practice, like anything else. Getting into wet labs, learning how to use the gonioscopy lens. The technical skill is already there if you’re a cataract surgeon. It’s learning the new techniques. And 40%, economic barriers. That’s a challenge to the global ophthalmology community and to industry that we really need to come up with affordable MIGS procedures. Not just procedures for the high-income countries. But procedures that can be done economically anywhere in the world. Because glaucoma and cataracts are a global problem. And we need to address it from a global point of view. 33% of you said that MIGS devices are not available in your country or your practice setting. So, again, a challenge to the ophthalmology community and industry that we need to globalize these technologies. However, I think things like GATT or a needle goniotomy, you know, 50 years ago, pediatric glaucoma was being treated with a goniotomy like with GATT, with goniotomies done with a suture. I think procedures like that are a great starting point. They can be effective. As the global ophthalmology community and industry work to make these MIGS devices more readily available in all parts of the world. Okay? So, thank you for those answers.
And that concludes the slide show. So, I’ll stop sharing my screen here and we’ll go to some of the questions and answers. So, if you see down at the bottom of your screen, there’s the Q&A. And if you have a question, feel free to put it in here. And I’ll try to get to it. We probably have about 10 minutes of time for questions. So, the first question is: What is Durysta? Again, to review, Durysta is a biodegradable implant that has it embedded into it. When you inject into the anterior chamber, slow release of the glaucoma medication over a 6 to 12 month period. It’s being released 24/7. It’s really good efficacy for controlling intraocular pressure for patients that have problems taking drops. Maybe they have surface disease or lots of compliance issues for whatever reason. In my practice when patients have compliance issues, they can’t get the drops in, we’ll very quickly think about Durysta because it’s very safe and simple to implant. Great question.
Okay. Next question: You gave a wide range of duration for which the drug delivery systems work. How do you determine when exactly to re-insert a new one? And will there be a second procedure to remove the remnant of the iDose? That is a great question. So, I don’t think we have firm answers to that just yet. It depends on the device, right? Each of these companies are trying to answer that question in different ways. So, for instance, with the iDose, there are trials being done where you leave the first iDose and two years later put a new one in and leave the first one there. Compared to going in and removing the first one, which is pretty easy to do, and then inserting another one to get another couple of years. So, I think the answer to that question is not evident yet. And it might also depend on which one. Because with Durysta, that biodegradable implant eventually dissolves and you can go back and do another one. Now in the United States, unfortunately reimbursement or what insurances will pay for are dictating a lot of that right now. But I hope that we will evolve to a point globally where we can use these medications when it’s appropriate for our patients and we can reuse them when the effect starts to die off. I also think that the newer technology — remember, we’re at the very beginning of this. This drug delivery, we’re gonna see a lot of growth and expansion over the next decade. I think that we’ll start to see these systems get better, where the drugs last longer. Maybe last three to five years instead of one to two years. The next question: Which type of glaucoma surgical technique is easy and feasible for less implications for glaucoma patients? Man, that’s a great question. So, if we’re talking about MIGS procedures, I think you could — I think there’s a lot of variability in which of those procedures? So, a very simple way that you might start thinking about it or how I think about it. If it’s mild to moderate glaucoma, or more mild glaucoma, I’m thinking about the trabecular meshwork procedures goniotomy or a microstent or a microplasty. And usually a 2 to 4IOP reduction with those. Very low risk, not a lot of complications, not a lot of re-operations. It’s a safe thing to do. Now, if the patient has moderate glaucoma, in my practice — and I’m not everybody — I start thinking about the supra choroidal ones. Because I see a little bit more pressure reduction with those. But you’re more likely to get things like a hyphema, might get a little bit more inflammation. Might not be right for every patient. But I at least start to think about that. For the moderate heading more towards the severe, for the more worrisome patients with the more advanced disease, thinking about the trabecular — or I’m sorry, the conjunctival procedures, the Xen. Think about a trab and modify is that trab so it’s safer. What else? What other questions? That’s a great question. And that brings up a good point. We need a lot more data here. We’re still very early on in the MIGS data. And there’s not a tremendous amount of comparative studies where you’re comparing one MIGS procedure to the other one. There’s just so much variability, right? So, there’s still a lot to learn. And, you know, I had a conversation recently with a cardiologist and I was telling them about MIGS. He was absolutely dumbfounded. Let me get this straight, you’re putting stents in the eye, but you don’t know where the obstruction is. And to him, that was really crazy. Because in cardiology, they do a catheterization, they know exactly where the blockage is in your coronary arteries and stent that specific spot. Made me realize, we still have a lot to learn in glaucoma. Glaucoma I think is a very complex disease and we don’t — not all glaucoma is the same. So, not everybody responds to reducing outflow resistance at the trabecular meshwork. Maybe it’s farther down the system, the uveoscleral, episcleral, venous pressure. So, I think we need more testing, more sophisticated diagnostics which will then help us guide our surgical options for these patients. What about — so, next question — what about chronic narrow angle glaucoma? That’s a great question. Let me preface this. I’m not a primarily a glaucoma specialist. I am anterior segment surgeon who does cataract surgery as my primary procedure. But over 30% of my patients have glaucoma. So, I’ve immersed myself into this MIGS space. I would say that when I have chronic angle closure and there’s maybe some PAS, some periphery anterior synechiae, I have used the hook, the goniotomy, you can tease off the mesh and the meshwork. We’re trying to open up the angle and prevent further progression of the chronic angle closure. That’s my current thing. You always want to do gonioscopy in clinic before. If there’s a lot of PAS, rule out micro stents, you don’t want to do micro stents there, rule out some of the options. So, I’ll tend to use at the hook so I can tease away that — that PAS and then I hit them pretty hard with steroid afterwards to try to prevent it from recurring. What is the approximate effect on endothelial cell count with these procedures versus the traditional ones? That’s a great question. So, I think that the Cypass experience showed us we have to pay attention to the endothelial cell counts. Now all the FDA trials that is, you know, definitely being looked at. And I think what we’ve learned is that, you know, all intraocular surgery can reduce endothelial cell count. We know that from cataract surgery, right? We want to use MIGS devices that aren’t going to significantly increase that endothelial cell count. And what it seems to be is anything that gets close to the endothelium, any device that gets close to the endothelium can reduce the endothelial cell count. I think using micro shunts that aren’t anywhere near the endothelium, and not leaving things behind, canaloplasties, and these MIGS devices are safe, and we’re paying closer and closer attendance to that as we develop new technologies. But it’s safe. That’s the definition of MIGS — it’s quicker and safer, but still effective. And I think that’s the big advantage of these MIGS procedures is they have a lower risk profile than the traditional glaucoma surgeries like tube shunts and trabs.
Next question: Does all glaucoma — or do all glaucoma patients qualify for drug delivery? Certainly there’s contraindications, right? So, yeah, I wouldn’t put, you know, say a Durysta or an iDose in a patient with narrow angles or with uveitis. Now, would we use drug delivery like our colleagues do? Yes, of course. But for glaucoma, I would not. You do need to think about endothelial cells, if they have dystrophy or a corneal — not to do it. The patients that have trouble with compliance, ocular surface disease. Again, I think in low-income settings where you don’t always have great follow-up patients, drug delivery could be great. They come into a cataract camp, they’re blind from cataracts and there nor cataract surgery. But during the evaluation, they have glaucoma. And they’re going to return back to the rural setting and the likelihood of ongoing follow-up for glaucoma is going to be really difficult. That’s where a MIGS procedure combined with drug delivery could help that patient and buy them some time. So, again, I think we have a lot to learn. But it’s not gonna be for every patient. Next question. Great lecture, thank you. When do we stop the use of drops after implanting the drug application system? In the studies, we stop the drop. Wash the drop out, put the device in so we can measure the device. In the majority of those patients in the studies for the drug delivery, the pressures were very well controlled without having to take drops. That’s a clinical decision on a case-by-case basis. If they have four medication, it’s probably not going to replace four medications. It might replace one or two. If you have a patient on a prostaglandin and a beta-blocker and put in a Durysta on are a iDose, there’s a good chance the patient won’t need to be on drops for 18 to 24 months if it’s an iDose. But you’re monitoring the pressure, and as long as the pressure is staying within the target range, they don’t need drops, as it creeps up as it will over time as the dug dissolves and the device runs out of medication, you have to put them back on drops. You have to still monitor them. Again, I think as the technology develops, we’ll hopefully get longer-lasting drug delivery systems. And we’ll see just much longer duration of great pressure control.
Okay. I’m gonna take this one as the last — the last question because we are at 10:00. It’s been an hour. And I know everybody is excited to get their weekends going. So, this question is a great one: Can you combine different MIGS procedures in a single setting? Does it give better pressure reduction? Absolutely. So, that’s being done much more commonly now. And you can combine all different kinds. So, for instance, you can do an iStent on one side and a canaloplasty for a goniotomy or trabeculotomy or do an aloe flow or a supra ciliary procedure. You can combine them. In the US, that’s slow to involve because of the economic environment. The insurance companies won’t always pay for the combined. But if you’re in a setting where your care is not dictated or influenced by insurance companies, you can certainly combine them. And we’re seeing that evolve in the literature. And I think that combining MIGS procedures and even drug delivery procedures and get you closer to the efficacy of say, a trab or maybe not a tube, but, you know, a trab where you’re getting more and more pressure reduction. And those studies are slowly starting to come out. And I think that’s a future of the MIGS space. Great question. All right. It’s been an hour. This has been a lot of fun. I really hope that this has been helpful for you wherever you are in your MIGS or drug delivery journey. I do hope that we all agree that MIGS is here to stay and that’s going to continue to become a bigger part of our practice and it is going to offer safer options to our patients that have — that have glaucoma. And, you know, who knows? If we do this talk again in a year or two, it will probably look a lot different and we could look back at this one and say, wow. Look how far we’ve come? But please feel free to reach out and I wish all of you a happy and prosperous weekend. Thank you. Signing off.

Last Updated: April 26, 2024

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