In this special edition of Point-2-Point with Malik Y. Kahook, MD, we focus on Surgical Simulation & Minimally Invasive Glaucoma Surgical approaches. The session will starts with a basic introduction to angle surgery by Dr. Kahook. Several expert surgeons then discuss specific approaches to angle surgery with a focus on surgical simulation using artificial eyes. This is followed by surgical videos from the operating room to illustrate how simulation training can lead to successful adoption of new surgical techniques. A panel Q&A session concludes the event.
Lecturers: Dr. Malik Kahook, Dr. Leo Seibold, Dr. Mike Greenwood, Dr. Monisha Vora, Dr. Husam Ansari, Dr. Joseph Panarelli & Dr. Jella An
What we’re going to do today is something that I haven’t really seen done before on the Cybersight lecture series. We’re going to combine the use of simulation eyes along with real world surgical procedures, so that you can see how things translate from the teaching environment to doing a case from start to end. We have a great lineup of speakers that will take live questions during the process of some of the lectures that you’re going to see. And then we’ll finish up with a live question and answer. So please fill in questions in the chatroom. And again, we might answer some of them along the way, and then we’ll save some of them for the end so we can do a live question and answer with a discussion amongst the panelists.
These are the panelists. We will start off with Dr. Monisha Vora to cover the OMNI canaloplasty device, Dr. Leonard Seibold will cover goniotomy, Dr. Michael Greenwood will cover TM bypass devices. We’ll have Dr. Jella An cover endocyclophotocoagulation, or ECP, Dr. Husam Ansari will cover XEN, and we’ll finish off with Dr. Joe Panarelli covering Preserflo.
Before we get into that, I just want to cover a couple of slides on the basics of what you’re going to see. And I’ll start off by saying there is absolutely no way that we can cover all of the different devices that you see listed here. One of the really great things about being a glaucoma surgeon today, is that we have so many different options. Whether it’s the MIGS devices with the implants, the different goniotomy approaches, and then some of the novel filtration or full-thickness procedures like the XEN or Preserflo that is making its way to different markets around the world. So I’m excited to go over some of these procedures with you. But again, we’ll touch on some of these verbally, some of them will actually be in video form.
Just a definition of MIGS, what is MIGS? It’s an ab-interno approach that is minimally traumatic, at least modestly efficacious and the efficacy should be sustained. It is an extremely safe procedure on par with cataract surgery, and it involves rapid recovery. Again, similar to cataract surgery with minimal impact on quality of life.
What about adding angle surgery to practice? So if you’re thinking about starting angle surgery, what are some of the things that you should be aware of from a patient selection standpoint, day of surgery, pre-op, drop, and post-operatively? And then some follow up pearls that I’ll share with you.
One thing that I always like to say is that angle procedures are not just intended for mild to moderate combined with cataract surgery, which is how we usually see it defined. You can use it for moderate disease, you can use it as standalone, you can also use it for severe disease. And in my case, I typically choose to combine procedures when I’m looking at a moderate glaucoma patient who might be on multiple medications. For a mild glaucoma patient combined with cataract surgery, I might choose something like a goniotomy, or an ECP, one or the other. And again, with moderate or maybe somebody on two or three medications or more, I might combine an in-flow and out-flow procedure.
And then for moderate to severe, when you get into that severe category, you can still do angle procedures, particularly in those patients who have angle closure with extensive synechiae, something like a goniotomy can have a real big wow effect, as far as the amount of IOP lowering. And then again, you can also think about combining in-flow and out-flow procedures with ECP and then something in the angle, whether it’s an implant or a goniotomy.
Pro-operatively when combined with cataract surgery, you should always consent the patient for plus or minus the angle procedure. You don’t always have the chance to complete the angle procedure at the time of combining it with cataract surgery. So it’s always good to have that conversation with a patient that it’s a plus or a minus. Of course, 99% of the time we’ll be able to do the angle procedure and all goes well.
Discuss recovery and that it might be different than typical cataract surgery. Because many patients have friends who’ve had cataract surgery, if their post-operative course is a little bit different, you just want them to be prepared. They’re not just getting the cataract surgery, they’re getting something for their glaucoma as well. From a dilation and pre-operative drop standpoint, it’s very typical, exactly what you’d do for a cataract surgery you would mimic that for this type of procedure when combined with an angle surgery.
And then discuss the positioning, this is one of my favorite things to talk about when new surgeons or surgeons who are new to angle surgery are attending some of these lectures. You should always talk to the patient before going to the operating room about turning their head, turning the microscope, just so they’re prepared for that repositioning that happens after cataract surgery. And the reason for this is the patient often will hear the commotion happen in the operating room in making this change in position, so it’s good for them to have an idea of what’s going on.
Now, if this were a standalone procedure, then you would do antibiotics, you also constrict the pupil because there’s no need to dilate. You can constrict the pupil to protect the underlying structures. And for the Pilocarpine, we typically use 1% q five minutes times three. Everything else is as above.
What about intra-operatively? You can use miotics in your first few case.And in that case, it’ll enhance your view to the angle. And of course this is with standalone or if you’re doing it subsequent to the cataract surgery. Just to give you a little bit more protection and also it gives you a little bit more visibility of the angle structures. Try and pick routine cases with cooperative patients and consider a peribulbar anesthetic to just calm everything down. Even if you’re a topical anesthetic surgeon for cataract surgery, you might want to consider using peribulbar for the cases when you’re first starting out with angle surgery.
Hydrate the wounds really well to make sure that you can inflate the anterior chamber to a pressure of around 25 millimeters of mercury. And that gives the ability of the aqueous to push any reflex heme back into the collector channels and it gives you more comfort in the early post-operative phase.
There’s some positioning things that I think are extremely important. And there’s this link to a “Glaucoma Today” article that you see at the bottom of the slide that I think is extremely important. Really good for new surgeons, training surgeons, and also those who are new to angle surgery, to go and read this article from Shakeel Shareef. And in this article he talks about positioning your elbows, that when you’re doing cataract surgery alone your elbows are at your side. Whereas with a combined MIGS procedure, one of your hands is usually extended to hold the gonioscopy lens. From a cornea standpoint, you’re working through two different incisions when you’re doing cataract surgery. In the case of combined with MIGS, you have one hand outside the eye, one hand inside of the eye doing the angle procedures itself. Again, holding the gonioscopy lens with the non-dominant hand.
There’s also the idea of being a bimanual surgeon when you’re doing cataract surgery. Whereas the motion and the maneuvers that you’re using with one hand internal, one hand external, these are things that take some time to get used to. From an operative space standpoint, cataract surgery you have several millimeters from the back of the cornea to the posterior capsule. And when you’re doing angle surgery, you’re working in about one millimeter of space. So there’s a significant difference in the environment that you’re operating in.
This is Shakeel Shareef in the pictures that you see here. And you can see on the left hand side, typical phaco position with the elbows on the side. On the right hand side, you can see that his left hand is actually extended, so not the typical position. And it’s just something to keep in mind and to practice in the operating room.
Another part here that we maybe don’t focus on as much, is just hand positioning itself. When you’re using a gonioscopy lens, it’s really important to keep that hand very stable. So if it’s a right eye and you’re operating from the temporal side, your left hand would be resting on the forehead. And then, of course, the opposite of that, your hand would be resting on the zygoma, just to give you more of a stable hold on what you’re doing.
I also want to mention that when you’re placing viscoelastic on the cornea, there’s a tendency to overuse it before coupling the gonioscopy lens on top of the viscoelastic. And one thing to get in the habit of is just putting the viscoelastic on the back of the lens and then placing it over the cornea, rather than putting it on the cornea and placing the lens over the viscoelastic. That’ll allow you to save some viscoelastic, it also helps to dispace bubbles better and any heme that might be on the cornea, as you’re putting the viscoelastic down on the cornea.
Don’t use the lens to help direct the eye, there’s a tendency to want to do that. That’ll just cause stria. So you have to position the patient and really just rest the lens, float it on the viscoelastic. And then make sure you zoom in. And you see this picture here, this inset, you really want to have a view that basically covers edge to edge of the gonioscopy lens, and you don’t want to see the wider surface area of the eye. You want to really focus in on the trabecular meshwork in order to do a good job with the procedure.
This is a procedure that is basically simulated for angle surgery. At the end of cataract surgery, when you’re just about to start getting into angle surgery, it’d be really good to take 10 of your phaco cases at the end of the cataract surgery, when all is said and done, reposition the patient, reposition the microscope, and then take your chopper and go into the angle and act like you’re doing the angle procedure. If you do that for about 10 cases before you do your actual first angle surgery case, you’re going to be comfortable with the scope, repositioning of the patient, the motion that you’re doing with your hand. And you also get the staff in the operating room accustomed to helping with repositioning of the patient and the microscope. So it’s just something simple you can do a few cases before you do your actual first angle surgery case.
Wound construction, extremely important. We have a tendency when we’re doing straight phacoemulsification, to go towards the perilimbal vessels and to nick the perilimbal vessels to get a little bit of oozing. In the case of a combined cataract with an angle procedure, or just a standalone angle procedure, we really don’t want to do that because the blood can then mix with the viscoelastic on top of the cornea and obstruct the view. So always try to go a little bit more anterior than you’re typically used to with a standalone cataract surgery.
A common question that comes up, is should you do the angle procedure before or after cataract surgery? And this is hotly debated amongst surgeons, everybody seems to have their favorite way of doing it. We did a study where we looked at the view of the angle pre or post cataract surgery to see if there was a major difference. Long story short here, there really was no difference in the quality of view. Whether you do the angle surgery before or after cataract surgery. And I think you should do what you’re comfortable with. Again, every surgeon tends to have their bias. I tend to do mine after the cataract surgery and there’s some surgeons who say you must do it before the cataract surgery. So do what you’re comfortable with.
And this is putting it all together. This is my friend, John Berdahll, from South Dakota doing his first goniotomy procedure with this device. This is the KDB device. Going left to right after putting the gonio lens on top of the cornea, you can see pretty smooth, he’s an experienced angle surgeon before doing this. And then right to left, you could zoom in a little bit more so that you’re a little bit more focused on the trabecular meshwork, something that you should do when you’re first starting out. But you get an idea of the stability, there’s not a lot of wasted movement. Very deliberate in the movements that he’s doing. And then he goes in with Duet forceps and he pulls the strip of trabecular meshwork off of the iris. And all done with the case. So it gives you an idea of what the technique should look like once you’ve refined it.
A fluid wave is something that you should think about doing at the end of any of these angle procedures. I really like the idea of telling the patient that we were successfully able to unroof the canal. In this case, this is post goniotomy. And you can see in the upper left hand corner the blanching of the vessels with injection of BSS into the anterior chamber. Just gives you an idea of how the anterior chamber’s now connected to the collector channels. And it is a nice sign to verify that you’ve done what you’re aiming to do.
Post-operatively, treat similar to cataract patients. Antibiotic/steroid/NSAIDs, which you typically do. Plus or minus a glaucoma medication when you’re combining with cataract surgery, this is something that different surgeons have a like and dislike of doing. Some surgeons like to always add a glaucoma drop while their patient is on a steroid, just to avoid that steroid response glaucoma that you can get. And some surgeons like to stop all glaucoma meds and just follow and restart as needed.
For standalone, it’s very similar. Antibiotic/steroid, typically not an NSAID in those cases. And then plus or minus a glaucoma drop. And then you see the patient back post-operative day one.
Some follow up pearls, like I said, steroid response is not uncommon after ab-interno procedures. So it’s something that you want to watch out for. I tend to keep patients on at least one glaucoma medication while they’re using the steroids post-operatively and then I stop that as soon as I can. Some surgeons like to stop drops completely if the post-operative pressure is 15 or 15 and under. You can keep the patient on one or two glaucoma meds if needed, depending on the nerve status. So if you’re a little bit more worried about a particular patient who has more advanced glaucoma. And then you can restart medications one by one as needed, depending on what you did with the algorithm above. Again, this is not set in stone, it’s really what you like to do. I’m somebody who errs on the side of safety with steroids causing IOP elevation, so I keep the patient on a PGA or any of their other drops during that early post-operative phase. And then I stop them as soon as I can and restart as needed.
These are some resources that are on Cybersight. KEOGT.com can also be accessed with some of these lectures. You see YouTube, Twitter, and Instagram. Please contact me and let me know if we can do something better with these lectures. Also, what topics you might want to see on future Point-2-Point lectures.
What you’re going to see subsequent to this, is the various lectures that I just described, starting with Monisha Vora, talking about the OMNI canaloplasty device. As these lectures are playing one after the other, please feel free to put in questions in the chat box and we’ll try to get to them live as the lectures are going. And then we’ll circle back at the end of the last lecture for a live discussion with all of the panelists, where we can answer some of your questions that you’re putting into the chat room as well as some of those that you submitted at the time of registration. I’m really excited to see these lectures. Thank you for joining in and lets start with some of the basic lectures to follow. Thank you.
[Monisha] Hello, and welcome to the ORBIS MIGS Global Session. My name is Monisha Vora, M.D., and I am a clinical instructor on the glaucoma service over at Wills Eye Hospital in Philadelphia, Pennsylvania. Today, I have the pleasure of speaking to you about my experience with the OMNI Surgical System.
The OMNI Surgical System combines two distinct implant-free procedures within one device. It performs a transluminal viscoelastic delivery as well as a titratable trabeculotomy. This procedure, like any other MIGS procedure, does require intraoperative gonioscopy to do the angle. And I typically use a Swan Jacobs Gonio Prism Lens in my left hand, as I am right hand dominant.
The device is typically primed with a cohesive viscoelastic, such as Healon, and the viscoelastic is placed in number one, which is the Luer fitting at the end of the device. The priming lock, number two, is then removed, and the device is handed over to the surgeon. As you can see, it has a great ergonomic design with gears that allow the microcatheter to retract forward and backward, in and out of Schlemm’s canal with ease and precision.
Preoperative evaluation and planning. The OMNI Surgical System is indicated for primary and secondary open-angle glaucomas. Ideal cases include pseudoexfoliation and pigment dispersion glaucomas. The angle anatomy should be thoroughly evaluated prior to surgery in the office. And it is important to set yourself up for success. And that means avoid choosing patients with any sort of abnormal angle findings or features. This may include peripheral anterior synechiae, neovascularization, which could lead to intraoperative bleeding, or any sort of narrowing of the angle, which would preclude a good view of the angle and therefore an easy passing of the OMNI Surgical System.
I’d like to include an open-angle treatment follow up for 18 months by a group out in Poland, which was presented at the 2019 ESCRS Conference. The purpose of this study was to analyze the safety and efficacy of the OMNI procedure in reducing intraocular pressure and the number of glaucoma medications in eyes with open angle glaucoma. 24 eyes, of which 14 had standalone OMNI and 10 had combined OMNI with phacoemulsification, had 18-month follow-up. It was found that these eyes had about 38% reduction from preoperative pressures and a reduction of 1.5 glaucoma medications over all.
And now, I’d like to get into some of the videos. We’re going to see several videos ahead, one of which is an animation that shows how the OMNI Surgical System works.
I’d like to thank Sight Sciences for providing this surgical system animation video.
I think it’s really important that before you try any MIGS procedure, you understand exactly what it is that the device does and how it performs. The OMNI addresses the conventional outflow pathway of the eye. And it allows more aqueous to outflow from the conventional pathway by first accessing the trabecular meshwork and then Schlemm’s canal. Of course, after Schlemm’s canal, we proceed to the distal collector channels and this is how the aqueous egresses from the eye.
A clear corneal incision is made and the OMNI device is introduced in the surgeon’s dominant hand. Using the non-dominant hand, the gonio prism is then placed over the eye. The OMNI Surgical System is advanced across the pupil and the trabecular meshwork is excised. You can see here how the cannula is used to pierce the trabecular meshwork and then aimed anteriorly towards the corneal endothelium. This allows the microcatheter to easily slip and slide into Schelmm’s canal. The microcatheter then advances 180 degrees and then once it is retracted back into the cannula, that’s when viscoelastic bolus is delivered.
Here we have the SimulEYE demonstration that shows the OMNI Surgical System cannula advancing across into the eye, and then piercing the trabecular meshwork. And I will show it here twice so that you can get a good idea of how it works. Again, the cannula is advanced through the corneal incision, across the pupil, where it pierces the trabecular meshwork, and then it is aimed anteriorly towards the cornea endothelium to allow the microcatheter to go easily and smoothly into Schlemm’s canal.
And now I’d like to demonstrate a live case of my own, which I call my toughest case, that really highlights many pearls of how to use the OMNI that I have learned over time. So the number one rule when performing MIGS surgery, is to get an en face view of the trabecular meshwork. Make sure to magnify yourself all the way up so that you have the view that you need. If you don’t have the view, you’re going to have a very difficult time performing the procedure.
Remember to not orient the cannula parallel to the trabecular meshwork or the iris. As I mentioned before in the SimulEYE video, this can cause inadvertent placement of the microcatheter into the iris and potentially cause problems such as an irregular dialysis or a cyclodialysis cleft. If you’re having trouble finding the right view or getting the OMNI Surgical System device into the eye, it may take several refills of viscoelastic into the eye to form and reform the chamber. And this is okay. Use plenty of viscoelastic to make sure you have the proper view.
Here I have reformed the eye with OVD, and I’m going back again. Bringing the cannula across the eye, piecing the trabecular meshwork and then most importantly, right there, aiming anteriorly towards the corneal endothelium. That will really ensure that the microcatheter goes straight into Schlemm’s canal and does not go downwards, potentially into the iris. You also want to make sure that you don’t pull the cannula into the anterior chamber too quickly. You want to keep the tip of the cannula close to the trabecular meshwork, that way you have a nice amount of tension on the microcatheter which will allow you to perform the goniotomy portion of the procedure. I also tend to mag out when I perform the goniotomy portion so I can make sure I see a more global picture.
In summary, the OMNI Surgical System is one of the many MIGS devices out there available to the ophthalmic surgeon, to treat elevated intraoperative pressure. It is always important to learn the mechanics of any device prior to performing the surgery on a live patient. The SimulEYE is an excellent way for any surgeon, whether novice or advanced, to practice their technique before they perform the surgery on a live patient. We always use these simulation eyes for resident and fellow wet labs that I help to lead at Wills Eye Hospital. They really help our trainees perfect their technique so they are set up for success during surgery. Thank you for taking the time today to join us.
[Leo] Hello, everyone, this is Leo Seibold with the University of Colorado and I’m going to be discussing goniotomy with the Kahook Dual Blade. These are my financial disclosures.
So the Kahook Dual Blade is a precision goniotomy blade that was engineered specifically for the angle. It not only incises the TM through paired incisions, but this allows for excisional goniotomy or removal of trabecular meshwork tissue as well. This augments aqueous outflow through that traditional pathway, making it a very versatile device that can be used in many clinical scenarios. It can be used as a standalone or in combination with cataract surgery. It is nice that you don’t leave an implant behind and it has an existing billing code as well.
There’s a few key design features with a Kahook Dual Blade. First off, the sharp tip of the device is designed to pierce through trabecular meshwork and allowing you to seat the heel or footplate of the device within the canal. The ramp then lifts the trabecular meshwork and feeds it up to the dual blade, which create parallel incisions, allowing you to excise the trabecular meshwork.
We know the difference between incisional and excisional goniotomy. You can see here, from pathology slides, after an eye treated with MVR blade goniotomy, where you have collateral damage through the outer wall of Schlemm’s canal, and significant leaflets of residual TM left behind. Compare that with the Kahook Dual Blade where we see near complete excision of the trabecular meshwork tissue and no collateral damage.
These are what eyes will look like postoperatively. First on the left, the gonioscopy image showing you that outer wall of Schlemm’s canal that’s now exposed after removal of trabecular meshwork tissue. And then in the anterior segment OCT on the right, you can see the opening of Schlemm’s canal with removal of trabecular meshwork tissue.
These are the instrumentation needed for the procedure. First off, you need a keratome blade, at least one millimeter in size that can be enlarged. Followed by preservative-free lidocaine for anesthesia and then a cohesive viscoelastic. In the middle there, you see a Swan Jacob’s gonio lens, or a direct gonio prism, the Kahook Dual Blade itself. And the irrigation and aspiration with a coaxial device or simply an anterior chamber cannula on a BSS syringe. And then finally, a miotic agent to complete the case.
Preoperatively evaluating patients. Your best candidates are any patient with open angle glaucoma, or any secondary open angle glaucoma. And any disease severity, although mild to moderate patients may do better than more severe. Any lens status can be included. Those eyes that have a coexisting cataract, it’s nice to pair at the time of cataract surgery. But you want to select, for your first few cases, eyes that have a deep angle and a nicely pigmented or easily-identified trabecular meshwork, like in the top gonioscopy image. Those eyes with more lighter pigment can be a little more challenging identifying those structures for your first few cases.
What kind of expectations are there for efficacy with the Kahook Dual Blade? Well, as you can see, a growing number of literature out there describing the efficacy of the device. If we look at the mediums, we see that in most studies, IOP reduction from a preoperative level of about 18 millimeters of mercury down to 13.8, or about a four and a half point drop. This also is equivalent to about 26% reduction in IOP. At the same time, reducing dependence on medications, on average, by about one.
Intraoperatively, corneal incision, I think, is important. From the very start of the case, you want to avoid vessels and maybe flair it internally to allow you to pivot the blade within the wound. Positioning the patient and the scope appropriately to give you a nice en face view is important. You want to optimize that positioning and visualization before you proceed with the procedure. And then starting the goniotomy, you want to keep the tip of the blade about 10 to 15 degrees up, pushing outward initially to pierce through the trabecular meshwork. But then relaxing it and allowing the blade to glide across the angle. If the eye is moving, you need to relax pressure. And if you’re seeing too much of the ramp, you need to seat the footplate a little deeper within the canal. Heme is going to happen with any angle surgery. You want to keep the eye somewhat firm with viscoelastic if you’re seeing too much. Or add viscoelastic to displace heme and remember never treat what you can’t see.
So here we’ll go through a video just demonstrating the three different techniques with the Kahook Dual Blade. First, is the outside-in technique. You start from the far left of your view, proceed to the middle, and then from a backhand from the right to the left. Next, the inside-out. This is just the opposite. You start opposite of your wound, proceed all the way to the right in a forehand, and then reverse the blade and go all the way to the right of your view in a backhand motion. And then finally, the mark and meet. And this is nice because you keep the blade alway in a forehand motion, making an initial cut to the left and then starting in the far right and bringing it back to that initial incision.
Before you get started in an actual patient, practicing in the wet lab is key. And the SimulEYE MIGS eyes can be a real asset to you in getting comfortable with this procedure. And we’re going to take you through some videos and how we use these eyes to practice the Kahook Dual Blade.
So first you see this is actually the KDB GLIDE, the latest iteration, showing you some of the chamfered tips on the footplate of the device, which allows for easy gliding. After you make your corneal incision, you fill the eye with viscoelastic, apply a liberal amount on the cornea. This is our Swan Jacobs lens, which will allow us to see a direct view of the angle, which we now see. This is just showing you how you can tilt the lens to the left or right and this can add about one to two clock hours of view, to allow you to treat an additional amount of trabecular meshwork. You want to make sure you zoom in like we are here.
And in this first technique, this is the mark and meet. So we’re making an initial incision to the left and then proceeding from the far right, and bringing it back to the initial incision. And you can see, I’m a little bit shallow. You can see a lot of the ramp of the device, I’m really just skating on the top of TM.
Now in the second pass, in a different eye, you can see here I get hung up because I’m pushing too hard. The whole eye is trying to rotate. So I back up, refeet and then I’m able to proceed not pushing out so far. And here it is again. This is the mark and meet, finally getting it right. So I’m making the initial incision, starting to the far right, and you can’t see too much of the ramp, but I’m not getting hung up on, I’m at the right depth, and you see a nice gliding and removal of the trabecular meshwork.
Next is the inside-out technique. This is my preferred technique, we’re starting opposite our wound, proceeding far to the left of our view. Then reversing the blade, now this is a backhand motion and going as far to the right as we can. This, I think, allows you to treat the greatest degrees of angle.
And finally, the outside-in. So starting out with a backhands from the far left, moving to the right, and then from a forehand motion we’re starting from the right and proceeding all the way to the middle of our view to complete a free-floating TM strip. And now, moving on to actual patient cases.
You can see the gentle side to side motion to get into the eye through the corneal incision. Again, zooming in is key. And then you can see the gentle upward tilting of the blade and the outward pressure it takes to get into the eye. Once you’re in the canal, then you can see a nice gliding motion of the blade. Switching it over to a backhand now, this is that inside-out technique. And we’re going as far as we can to the right as long as our view allows. And here you see a nice opening of the cleft. Now, in this case you can see I’m starting out okay with a little bit of outward pressure. But I continue to push a little too far, now the eye is rotating. This is a good example of too much outward pressure. But when I reverse and go from a backhand motion, you can see the eye stays nice and steady, I’m seated a little bit better, not pressing too far outward. The eye should not move like this.
Next you’ll see the mark and meet technique. So again, we’re making an initial incision to the left of our view, we’re keeping the blade in the forehand motion. Starting to the far right and then proceeding back to our initial incision. And this should create a nice free-floating flap. And then, finally, the outside-in technique. So here we’re starting first with a forehand motion from the right to the left of our view. We’re going to stop here, reverse the blade to a backhand motion and start from the left and head to the right until we meet where we finish with our initial incision. And this, again, should give us a nice free-floating strip of TM, which you can see coming off the tip of the blade there.
Postoperatively, I usually treat these patients very similar to a postoperative cataract case with four weeks of the steroid taper, a week of antibiotics. If they’re combined with cataract surgery, I’ll add NSAID. And depending on surgeon preference, Pilocarpine may be added as well, postoperatively.
In terms of stopping glaucoma medications post op, this is very surgeon dependent. But I’ll typically continue at least one medication until they’re through with the steroid taper. And this can help prevent any steroid response, IOP spikes you may see. If they’re on more pre op medications or they have more severe disease, I’ll usually continue more drops post op, or if they’re more mild and on less drops to begin with, I’ll usually stop these drops more commonly. But setting expectation is key and remembering that you can always taper off the glaucoma meds after the steroids have been tapered.
In conclusion, KDB is a simple, yet elegant, angle procedure which achieves excisional goniotomy. It’s effective, yet safe, and versatile enough to use in many clinical situations. The learning curve, like any new procedure, can sometimes be steep, but it’s generally short. And wet lab practice before your first cases with the simulEYE models can really help speed your comfort and learning the different techniques of the KDB. Thank you very much.
[Mike] Hi, my name’s Mike Greenwood and today I’m talking to you about trabecular meshwork bypass devices. Specifically the iSTENT Inject and the Hydrus Microstent. The ideal patient for these devices is mild to moderate open angle glaucoma. And in the US, they’re indicated to be done at the same time at cataract surgery. You want to have a normal anterior segment exam and normal angle structures. And for post-op expectations, most likely the IOP will settle somewhere in the midteens and the medication burden will decrease by .5 to 1.5 medications. The IOP decrease depends on the starting IOP. As we know from studies that the higher the IOP, the more lowering effet you get. And the more medications you’re on to start with, most likely you’ll be able to get off some medications as well. It takes about a month or so for everything to settle in, but after that patients do quite well.
Here you can see what the device looks like. Each iSTENT Inject is preloaded with two stents. The stents slide down a trocar which is triggered by a small button on the handheld device. And you can see the details of the device on the right hand side where the flange will be facing you once it’s implanted into the trabecular meshwork.
When placing these stents, you want to put them as far apart as you can or about two to three clock hours apart. Again, the main goal is just to get the stents in and so when you’re first learning, you might not be able to get them two to three clock hours apart, you want to use whatever is best available to you. But in general, if you can get them about two to three clock hours apart, that is the ideal positioning.
When placing the stents, it’s very important that the stent is perpendicular or radial to the trabecular meshwork. And you want to place the stents about two clock hours apart as we showed before. If you have the trocar inserted at an angle, it can cause some trocar bias and that’ll make it hard for the stents to slide down.
In this slide you can see what we mean by trocar bias and not having the injector perpendicular to the trabecular meshwork. You can see that it’s just angled slightly and that trocar bias is going to prevent the stents from properly flowing down the trocar and getting into good position in the TM.
Now you can see that we’re in the wet lab here and I just need to lift my left hand and lift the gonio prism just a little bit, and you can see with my right hand I just kind of gently wiggle in my incision to get the device in the proper position. Again, you can see that protective sleeve over the trocars. I like to get that in good focus and in proper position, and I’ll just gently slide the sleeve back to expose the trocar. And you can see that there’s a little notch where you can see down the trocar and see the two stents in position. And now I’m just gently showing you, if you rotate it to the left or to the right, you can get a better view of that little notch where you can see where the stents are. When you’re getting ready to place the stents, you want to have that notch in view so that you can make sure there’s no trocar bias. And I’m just demonstrating and showing again, when you move to the left you might need to rotate the barrel a little bit so you can see that notch.
So as I mentioned previously, I like to start off on the right hand side, trying to avoid that bubble there for you. But again, now I’ve made contact with the trabecular meshwork and I’m just showing you how much you can wiggle that trocar and you can see the trocar bias there. So you want to have a nice, neutral trocar so that those stents can slide down the trocar shaft uninterrupted. You want to gently dimple into the trabecular meshwork and here you can see I’m gently dimpling in, getting ready to push the button. I fire, nothing happens. I had a little bit of trocar bias there and again, I’m getting used to the tissue in the wet lab, this is my first time placing the stent. So what I do is get it in good position and click the button again. And the second stent launches down and hits the first stent and puts it into a good position. Kind of like two crochet balls hitting against each other.
So now I get ready to fire the second stent. Again, I’ve got a good feel for it, so I go ahead and push the button, try and avoid any trocar bias. And that one’s pretty good but it’s not quite seated properly. But it’s in good position. So what I do is just take a deep breath and gently insert the trocar back into the inlet, because it’s facing me, I’ve got it in good position. Once I’ve got it engaged, then I’ll just re-engage the trabecular meshwork with the trocar, having the stent in good position. And then I’ll fire again. With each of these devices, you get four fires. And so I used two on the first stent and now I did a third one, which misfired, and then I do the fourth one there. And you can see that that remains in good position after I’m all done.
Whenever it’s not in good position, if you have it not implanted properly, if it’s facing you, how you want it to be, that’s the easiest way to rethread the needle, so to speak, and rethread the trocar and get that stent into good position.
So here’s a real life case. Again, showing some trocar bias. And so again, you get everything in good focus, wiggle in your incision, and pull back on the protective sleeve to expose the trocars. And what I’ll show here, which you don’t get in the wet lab, is that when you poke around in the trabecular meshwork, you do get some reflex bleeding. And again, I’m just getting ready to get everything in the right position. And I’ll puncture the trabecular meshwork with my trocar. And you can see, again, how much bias you can put on the trocar. And immediately there’s a little bit of blood reflex, so I want to have a good view, so I move over just slightly. And I can show you by pushing in too far, you can get some corneal folds. And so again, I had some bleeding, I don’t like that spot, so I move over just a tiny bit and get that stent in good position.
There you can see I fire the first stent down and there’s some reflex bleeding, which is not uncommon with this procedure. And instead of messing around and trying to figure out if that’s a good position or not, I still have one stent to deploy. So I move over to my second target, a couple of clock hours away. And depress the TM a little bit and fire the second stent down. And again, you get some reflex bleeding there as well.
Now, if you want to make sure that these stents are in good position, all you need to do is just go in with a little bit of viscoelastic, blow some of that heme away, and you can see that those stents are in good position. I did that in this case, but we don’t have it on the video. But that’s exactly how you want to go ahead and approach these cases.
This is a case that has a little bit better visualization. So you can see that I’m getting ready to deploy the first stent here. And you just have to barely dimple in to fire that trocar. You basically, the trocar sticks out from the base of the shaft, half a millimeter or so, and all you want to do is have the base of the shaft touching the TM and that’ll allow adequate pressure to deploy the stents. Here I’m a little bit narrow, meaning I”m only about a clock hour apart. But again, the goal is to get the two stents in and I felt that I had good pigmentation, which is where I like to target the stents. And so you can see how those stents are sitting there looking back at you in the trabecular meshwork in good position, about a clock hour apart or so.
Here you can see the Hydrus Stent. As we mentioned before, it’s a little bit longer than some of the other devices. But it’s eight millimeters in length and it’s made out of flexible Nitinol, which is very safe inside the body. It’s contoured to match the canal curvature and it has three open windows on the front and the canal-facing surface is completely open to allow for unobstructed collector channel access. And there’s a little inlet that’ll stick out at you.
So you can see here, once the stent is placed it has the inlet and outlet portion of it bypassing the trabecular meshwork, but the scaffolding also allows for a little bit of stretching of the trabecular meshwork, where it’s hopefully allowing it to become a little bit more porous. And you can see that it’s got a 90 degree span. And so those three things help improve aqueous outflow through the trabecular meshwork and getting to the collector channels, the inlet, the scaffolding, and the 90 degrees of access that helps. And you can see what it looks like on gonioscopy at two years post-op with that inlet smiling back at you and you can barely see the windows present behind the TM.
So again, we’re back in the wet lab, this time with the Hydrus Stent. And you can see what I’m showing here is just the proper angle is what you need. So you want to angle toward the cornea about 15 degrees and then this tip of the injector system is like a needle, so you want to bury that bevel just a little bit. And that allows the stent to get deployed into the canal. It’s deployed on a wheel mechanism, so you’re just gently rolling your finger down the wheel. And it’s intuitive because you’re wheeling it away from you, which deploys the stent. And here you can see the stent getting deployed into the canal behind the trabecular meshwork. And it’s kind of hard to see because there’s quite a bit of pigment in the wet lab eye. But what I’m showing is that it’s in good position but it may be advanced just a little bit. And so what you can use is the tip of the injector to actually go in the little inlet and just use a little bit of posterior pressure away from you. And then just slowly follow the curve of the eye to advance it.
Now here I’m retrieving it. And so what you do is you open, advance the wheel all the way to open up the jaws, and then you go in a little bit further than you think. And you maintain that posterior pressure and then just wheel everything back into you and it’ll follow the curvature of the canal. And so now I’ve got the stent reloaded.
So on this video you can see I’m getting ready to deploy the stent. I’ve already entered the eye. And you do need a separate paracentesis with this procedure, just to allow for easier access to the eye. So I made a secondary paracentesis just next to my main wound and I’m just getting ready to put the bevel into the trabecular meshwork. And I’ve got it angled about 15 degrees toward the cornea so that the stent deploys in the proper position. Again, if it’s parallel or slightly posterior tilted, it can make the stent go posterior which you don’t want to do. And so as the video plays here, you can see again. You just gently enter the trabecular meshwork, enough to puncture it. And then I’m just gently wheeling the stent down and you can see once it goes in, it’ll actually expand the canal a little bit. You can see the stretching of the trabecular meshwork. And it just slowly advancing the stent. I’m going very slow, very purposeful. Watching the leading edge of the stent. And now as I retract it, I kind of have to pull back a little bit to my right. Just to make sure I don’t disturb the stent.
Now it’s sticking out a little bit far, and so what I use is a viscoelastic cannula just to nudge that last little bit of the stent into a good position. So when you do that, you put a little bit of posterior pressure or pressure away from you, and then just gently follow the curve of the canal. Right now we’re just looking at the three windows of the stent. Making sure they’re all patent. It’s hard to tell in the video but we could see it in real life. And they’re hidden nicely behind the trabecular meshwork.
Once the case is done, this is just pumping up the eye, making sure the lens is in good position. But see some nice blanching, at the top of the screen here, for about three clock hours, showing that we got the stent in good position and that this patient is going to get a good response from this procedure.
And this is a case where I’m starting to deploy the stent, but it starts to dive a little bit posterior, if you watch that leading edge on the left hand side, you can see it dips down and going behind the iris root. And so instead of continuing, I just retract back and move to a new spot and deploy that stent. And that’s one thing you want to watch with this device, that it can dive a little bit posterior if you don’t have that proper starting position and you’re not in a good position in the canal. It’ll dive a little bit posterior, which isn’t a terrible thing, but what happens is the inlet that’s inside the eye next to the trabecular meshwork will actually face the iris and that’s when you can get some of the iris plugging.
Post-operatively what you want to watch from these patients. Again, it depends on the severity of their glaucoma. If they’ve got mild glaucoma, you’ve got a little bit more wiggle room. If it’s a little bit more severe glaucoma then you want to watch them extremely closely, of course. Again, I mentioned their IOP will settle somewhere around the mid-teens, somewhere one to three months post-op. And you can adjust some medications as needed and slowly peel them off. And you may stop them all at once and need to add them back on, it’s just something you need to be open with the patient at the beginning. But it takes a little bit of time to settle in.
And then of course you want to watch these patients and check their gonioscopy. Because the biggest thing that can happen with these stents is that every once in a while, you can get a little PIS to the stent itself. And if it’s blocking the inlet, then of course the pressure will go up a little bit. But in general, again, patients do quite well. They have an excellent safety profile, which we’ll show on these next two slides. And the biggest risk is just a little bit of reflex bleeding at the time of the procedure and of course, making sure there’s no PIS that forms over time.
So to summarize, in general, these stents, their ideal patient is mild to moderate open angle glaucoma. And their indication, again in the US, is to combine it with cataract surgery. Although, in theory, you could use it on any patient whether phakic or pseudophakic. They have a very good safety profile and they’re quite effective in helping these patients lower their IOP and get off some of their medications. Thank you so much and looking forward to the discussion.
[Jella] Hi, everyone, my name is Jella An. I’m a Director of Glaucoma and Fellowship Program at the University of Missouri in Columbia. We’ll talk about endocyclophotocoagulation, or ECP, today. The ECP’s a cycloablation with the additional advantage of direct visualization of ciliary processes during the treatment. The laser endoscope is comprised of 810nm diode laser, Xenon light source, and a high-resolution video camera that connects to a monitor. And there’s a foot pedal that you can control the laser duration and illumination. And the endoscope also comes in straight and curved designs and they’re reusable.
All of us are familiar with the transcleral cyclophotocoagulation, which is often reserved for end-stage glaucoma patients who are resistant to other forms of therapy. The concept of an endoscopic cyclophotocoagulation is similar. It uses the same diode laser to target the ciliary processes to decrease the production of the aqueous production leading to lower IOP.
But the end result of ECP is quite different from transcleral CPC, because with ECP you can really titrate the energy and duration, avoiding damage to the collateral tissue. And also require only 1/10th of the energy that you need for CPC. Because you don’t lose any energy to surrounding sclera and ciliary muscles as you do in transcleral approach. So all of these features minimize a commonly known vision-threatening complications of a transcleral CPC, including CME, hypotony, and phthisis. In fact, there’s been no report of a hypotony or phthisis with more than 50,000 cases of ECP worldwide in the past 10 years.
And here’s what it looks like en vivo. This is an ECP, you see the whitening of the ciliary body epithelium and a contraction of the tissue, which is the endpoint. And a surgeon can titrate the energy because you can visualize how the tissue’s responding and avoid a popping of tissue. And this is how the transscleral CPC looks like inside of the eye and it almost looks like a machine gun. You can imagine how this can relate to severe inflammatory response with acutely and chronically destroying the blood aqueous barriers and possibly leading to hypotony from complete destruction of the ciliary body.
This significantly reduced risk profile, the ECP, means it can be offered to a variety of patient population, of all types and severity. It can be easily required with the phaco or named any other MIGS procedure. And studies have shown the added IOP lowering benefit. The endoscope alone can also be used to visualize the angle and the focus can be pretty useful tool for any intraocular procedure, the complex procedures, trauma cases, and patients with a clouded cornea, or small pupil, or difficulty positioning, to verify or even to perform the placement of the IOL, the stent due to angle surgery or even the entire phaco.
All the ECPs are relatively easy to learn and pretty safe procedure. There’s a bit of learning curve getting used to looking at the monitors or microscope, and keeping the probe in the certain space, is a pretty tight space. So using a simulation can really help shorten the learning curve. So here I’m demonstrating how to use a simulation eye prior to procedure and the right side is a real patient. One thing that I found the use of a simulation eye is really helpful, is figuring out the correct angulation and range of motion to be able to use the widest angle without damaging the surrounding tissue.
One of the more common mistake that I see beginning surgeon, is not being able to use the wound as a fulcrum. So either burping the viscoelastic by pressing down on the wound, or excessively torquing the eye, while treating either superior or inferior quadrant. Also the difficulty in instructing the staff to properly orient the camera, or maintaining a constant distances from the ciliary body to the endoscope. So having a simulation session can really help figure out, it’s a small but important aspect of the surgery to maximize the benefit. And you feel much more comfortable your first few cases. So it could be really useful for training residents and fellows, of course. And not only that but it’s pretty critical for training the supporting staff who needs to be familiar with the setup of machine, and monitor, the pedal, proper handling in orientation of the probe that needs to be constantly adjusted during the procedure.
And this is how the simulation eye looks like. This company custom designs the eye with the ciliary body instead of the focused space.
The ideal first patient is a pseudophakic patient. Avoid phakic patients for the first few cases. It can also be combined with the phaco, of course. ECP can be done right after the IO insertion and before removing the viscoelastics. There’s no need to discontinue anticoagulants or any other pre-op medication. Patient remains face up and so no special positioning is required. But the procedure can be uncomfortable for some patients, so I suggest using intracameral lidocaine or a peribulbar block for the first few cases. You can use the same phaco incision, anything larger than 2 mm is recommended for wide range of motion.
Use a cohesive viscoelastic, so that it’s easier to inflate the focused space and also to remove it completely. Having a good space between the iris and the lens capsule is important,not only just for visualization, but also to prevent the treatment of the posterior iris surface, which can really increase the risk of inflammation. So for a first case, use a low-power no more than .2 Watts, avoid popping of the ciliary body, aim posterior side of the ciliary processes, avoid the iris, and treat widely, as widely as possible. Consider a second incision if you prefer. It’s important to treat the entire ciliary body, including the spaces, those valleys in between, to get the most effective IOP lowering.
The common complications post-ECP is inflammation, IOP spike. So treat them prophylactically. I usually give four doses of 250 milligram Diamox every six hour for the first 24 hours. And I bump up those steroids, usually use a Prednisone Pred Forte, every two hours for the first two days, and then lower it down to QID and taper over one month. You can consider NSAIDs or intraocular dexamethasone injection in patients who have a high risk of CME and inflammation. I usually continue all of the glaucoma medications until they’re done with the steroid, but avoid Pilocarpine because it can exacerbate inflammatory reaction.
It’s natural for new surgeons to treat conservatively but it’s pretty well-established 360-degree treatment is more desirable while still safe. And as I mentioned there’s really no reported case of hypotony or phthisis on patient with a full ag after ECP after 50,000 cases. This is Dr. Kahooks retrospective study in 2007 to compare under 300-degree treatment through one incision, versus 360-degree treatment of through two incisions, and 360-degree treatment was more effective in terms of lowering IOP and medication. And also importantly, there was no vision threatening or complications, including hypotony or inflammation.
How effective is the ECP? This is a prospective randomized match controlled study of 80 consecutive patients, combine ECP cataract extraction versus cataract alone. So you can see the baseline of IOP was 18 in both groups. But after three years, IOP in the treatment groups, so those who had ECP, was 15.4 on less than 1 medication versus 17.2 over two medications of the phaco alone group. The visual acuity outcomes and complications were similar between the two groups.
ECP can also easily be added as an adjunct procedure to an angle surgery, or Schlemm’s canal MIGS procedure. So a way to address the in-flow in addition to out-flow enhancement. And this is a longitudinal retrospective study, evaluating 12 months outcome of an ECP cataract extraction and iStent, also known as ICE procedure, in early to moderate open angle glaucoma patients, showed the addition of the ECP resulted in a greater IOP and medication reduction compared to phaco iStent alone. With similar visual outcomes and complication rate at 12 months.
Here’s another retrospective study demonstrating promising outcome of adding ECP to phaco KDB goniotomy in primary open angle glaucoma patients.
In conclusion, ECP’s ability to directly visualize the target tissue, titrate the treatment, leads to a safer and effective way to decrease intraocular pressure with a very low risk of vision threatening complications. And the endoscopy alone can also serve as a valuable visualization tool. The simulation and a dry run before the first few cases can really help the surgeon feel comfortable and shorten the learning curve associated with its unique setup. And avoid under or over treatment that can really affect the desirable outcome. Thank you very much for your attention and I look forward to answering your questions.
[Husam] Hello, everyone, I’m Dr. Husam Ansari from Ophthalmic Consultants of Boston and I’d like to thank you all for joining us. Today, I am going to be talking about the XEN Gel Stent. These are my disclosures.
The XEN Gel Stent is manufactured and distributed by Allergan, it is a six millimeter long stent made of porcine gelatine. And it is implanted through the sclera, such that it can then filter aqueous humor from the anterior chamber to the subconjunctival space. It does create a limbal bleb. And this draws comparison to the trabeculectomy.
Just some brief intraocular pressure results in comparison to trabeculectomy. So in general, you can see that the XEN Gel Stent is able to achieve mid-teens pressures, certainly, and in some cases even lower to mid-teens pressures. For the standard ab-interno approach, these are the instruments that I use. I have a 20 gauge sideport blade, cohesive viscoelastic, I’ve a 1.8 millimeter keratome blade, a marking pen with calipers. This is the Vera hook which allows for some fixation which you’ll see in the videos. This is a Katina single mirror indirect gonio prism, which is important for visualizing the stent in the angle, after deployment. This is the XEN injector itself, which we’ll go into more detail about later. And then I have some intraocular microforceps so that I can grasp the stent in the anterior chamber, and adjust its length, and even remove it if necessary. Not pictured here, but certainly required, mitomycin C antimetabolite.
This is a close up of the XEN injector, there’s a plastic cap with a metal post in the needle. And then this is the thumb slide that the injector slide that you advance forward to actually deploy the stentm and this yellow stopper is here to prevent accidental deployment. So some basic maneuvers. You simply pull the cap off exposing the metal post, you then pull off the middle post and you see the needle. Then you remove the yellow stopper and then you’re ready to deploy.
Now, as you advance this injector slide, as it’s going forward you can see the stent starting to come out. There’s a soft stop at the midway point of this injector, where you will feel it with your thumb that it stops. At that point if you go further, the needle will start to retract. So as the thumb slide is being brought more forward, the needle is retracting, and then the stent is fully deployed in the eye.
Now one trick if you actually deployed this stent outside of the eye, you can color it with a marking pen, and then reinserted into the injector. And this is actually very useful to visualize the stent after deployment if it’s underneath the conjunctiva, or you can see it in the anterior chamber, it’s just a matter of slipping it in with some forceps. And then pushing it in with a Weck-Cel sponge and then the metal post just to embed it. And then it’s ready to redeploy.
So there’s various implantation techniques. There’s the ab-interno technique, which I will show all of these. The ab-interno technique is the only technique that’s FDA approved. All the other techniques that are ab-externo are considered off label. But they are certainly in frequent use by many surgeons. There’s also a lot of variation in mitomycin C applications. Some surgeons do a subconjunctival injection, which is what I do. Some will open the conjunctiva and apply mitomycin via sponges. And then the total dosing of mitomycin is also quite variable, and no clear consensus has been achieved here. But we see dosing from 20 micrograms all the way up to 80 micrograms per case.
So this is our ab-interno close conj technique. Imagine the surgeon sitting temporally. Temporal for a right eye, after you make a small side port incision, fill the eye with viscoelastic, and I measure out three millimeters posterior to the limbus in three areas. It’s not in the video, but I made a 1.8 millimeter keratome incision inferotemporally, to allow insertion of the XEN inserter. I place the gonio prism on the eye to visualize the angle, and I’m aiming the tip of the inserter at the TM. And once I feel that it is in place, I use a Vera hook for fixation, and now advance the needle into the sclera to try to get to this distal three millimeter posterior point with the needle tip.
And once I get to that point, you begin deployment. And you move the thumb injector slide forward to get to that soft stop. And when you get to that soft stop, it’s important to actually give yourself some forward bias into the tissue so that as the needle retracts the XEN stent doesn’t come out of the eye with a needle as you withdraw it. And that’s it.
Visualizing with the gonioprism after implantation is important. And then irrigating the viscoelastic out of the eye and seeing a bleb form is the confirmation you need that you have outflow. There’s an ab-externo closed conjunctiva technique where you would start maybe seven millimeters posterior to the limbus, and advance in the subconjunctival space. And about two millimeters posterior to the limbus, you dive into the sclera and advance the tip into the anterior chamber. And then, in this case, the corneal traction suture is used for countertraction which can be very helpful. And then you deploy the stent as you normally would.
And then you can use some forceps to manipulate the stent in the subconjunctival space without actually breaking the conjunctiva. If you need to, say, pull the stent out a little bit and have it a little shorter in the anterior chamber.
The ab-externo open conj technique requires opening the conjunctiva with an incision. And then about two millimeters posterior to the limbus is where you begin the insertion. And it’s important to be able to see the tip of the injector in the anterior chamber and then deploy like normal. Now having open conjunctiva is great because it really allows you to grasp the stent with some forceps to actually pull it out or push it in, as needed, if you need to adjust the length.
And then this is very interesting, just getting rid of the injector all together and using a 27 gauge needle to create a needle track. And then simply removing the stent from the injector and feeding it in gently with some forceps.
We often get great pressures with this device, But inevitably, there’s patients where after surgery the pressure goes up a period and you have several options. One, of course, you can reduce topical steroid because there is a potential for steroid response. You can also instruct the patient on a self-performed digital massage. There’s always the option of adding back glaucoma medications, and bleb needling is commonly done with XENs. You also have to determine when it’s appropriate to return to the operating room to perform and open XEN revision, where you open the conjunctiva and see if you can break up scar tissue and re-establish outflow. You have to ask yourself when is it appropriate to implant a second XEN?. And then when is it time to do a separate procedure.
A lot has been said about the bleb needling rate after XEN implantation. Again, by comparison, the trabeculectomy group of the two versus trabeculectomy study, had an 8% rate of bleb needling. The XEN study seemed to show a higher degree of bleb needling. In the US pivotal study, 32% of XEN patients needed bleb needling.
So in summary, the XEN G el Stent provides very good IOP lowering and medication reduction. A low to mid-teens intraocular pressure are achievable. It allows for trans scleral filtration without opening the conjunctiva. The surgical times and vision recovery are probably faster than with trabeculectomy and tube shunts. The complication types and rates generally seem to be similar and perhaps lower than with trabeculectomy. There are many implantation techniques and options and it’s unclear which technique improves success, reduces complications, and improves needling rates. The post-operative needling rate seem to be high. And a lot of observation and vigilance is required because there’s so many different things that the surgeon can do when the pressure is going up.
[Joe] Hi, my name’s Joe Panarelli. I’m from NYU Langone Health. I’d like to thank all the organizers today for the invitation to speak, especially Dr. Kahook. I’m going to be talking to you today about the MicroShunt technique. Here are my financial disclosures. I am a consultant for Santen, which is the manufacturer of the MicroShunt.
So brief outline about what I’m going to walk you through today is just the background on the MicroShunt. And then we’re going to go through a step-by-step of the implantation technique with still images. Which is, I think, a nice way to learn. Then I’ll show you a video simulation with a SimulEYE. And then follow with my first MicroShunt implantation, to put all the steps together into one video, and show you some pearls on how to achieve successful implantation. And get blebs like we see here, which are not always so easy.
So what is the MicroShunt? It’s an exciting new device that is coming out here in the US. It is being used in Europe at the present time. It is essentially a tube or a shunt which is going to move fluid from the anterior chamber into the subconjunctival sub Tenon space, in a regulated manner. It has a lumen of 70 microns and a length of 8.5 millimeters. And you can see it here pictures, you can see what it looks like. It has this long center cylindrical shunt, it has these fins which are going to sit in the sclera and prevent migration.
So essentially, this is a tube without an end plate. Here’s some more of the specifications, in the terms of the size. And you see here what it looks like, the more proximal end will sit in the anterior chamber and it should enter through the trabecular meshwork, and the more distal end is going to sit outside the eye. So what we’re trying to do here is we’re essentially creating this hybrid surgery between the tube and a trab. We’re trying to get a filter in a very simplistic way. One of the exciting things is that the shunt is made of a SIBS material, which is a material that’s well tolerated by the human body. It’s used in cardiac shunts so it has been well tested before.
So in terms of the keys to implantation, I say at first because you can bury the technique once you’ve done many of these. But I think at first, here are five important keys. First is make a wide peritomy. It just gives you a lot of room to work, especially when you haven’t implanted the device. You want to be able to get back as far as you need to make that needle track into the eye, what you’re seeing here in the video.
I like to control bleeding whenever I’m doing a new procedure. There are some pros and cons to cauterisation when doing glaucoma surgery, but I think having a nice, clean, dry field is important at first. The needle track. I’m going to spend a lot of time on that because probably that’s the trickiest step in the implantation, but you’ve got to practice that. And that is something that you can practice with one of these model eyes.
You always want to make sure to check for flow. You don’t want to leave the OR, kind of like an Ahmed glaucoma drainage implant, you sometimes need to prime these devices and make sure you have a flow out the distal end. And like with all filtering procedures, a watertight closure. So if you want to get good results, you don’t want to have leaks. Because what do leaks do? It’s not that they cause low pressure, it’s that they cause the bleb to not have the height it needs and it can lead to early failure. So you really need watertight closure.
So let’s go step-by-step. We’re going to make a conjunctival peritomy, and like I said, I personally like about a four o’clock hour peritomy at first. You can maybe make this a bit smaller as you get more comfortable making the needle track into the eye. I often make a relaxing incision on one end and then continue my dissection across trying to make sure that I stay behind Tenon’s when I start my initial dissection. I often make a relaxing incision because it’s kind of hard to close with two wing sutures when you are trying to pull that pocket back further. It’s because you have to start that tunnel entry three millimeters posterior to the limbus. I like a good pocket, so I do some dissection posteriorly. Ike Ahmad is a big proponent of this. You want to be careful over the superior rectus because you can do a lot of bleeding, so you may want to stay a little more nasal or temporal when you start making this pocket.
I do like hemostasis with electrocautery. This is a procedure where you do need mitomycin C. And for the clinical trial, we all use the Mitosol kit. so use mitomycin C on four halfmoon soaked pledgets, .2 mg per ml. And we put these deep into the pocket and we left one of the pledgets kind of near where the distal end of the device was going to exit the sclera. You may end up injecting mitomycin C instead, but for most of us in the US, when we’re doing the initial pivotal trial, we used MMC soaked pledgets. Always want to be careful to avoid having the mitomycin C touch the leading edge of your conjunctiva. This is an area that you don’t want to be too avascular, this is an area that needs to be watertight.
This is a key step. So you removed your mitomycin C soaked pledgets, you’ve rinsed the area. Now you’re going to make a mark three millimeters posterior to the limbus. Here is a double step knife that you will use to make your entry. The reason is, is that you want about a one millimeter tunnel going into the anterior chamber. But you’ll see here, there is a wider portion of the blade, and this is used to create a pocket right here in the sclera where the fins of the device are going to get inserted into. You don’t really want this portion of the bleed making it into the anterior chamber.
This is what you want to see. You want to see the proximal end of the blade get into the interior chamber and this wider portion just make this pocket here in the sclera. After that’s done, you’re going to insert the device bevel up into the track and this is what you should see. The more proximal end should be coming into the anterior chamber here and here are your fins. Again, this purple circle, these fins are going to slide into these pockets here. It’s going to keep the device from migrating and it’s going to prevent any peritubular flow.
We want to, again, prime the device. You’re going to take BSS on a cannula, you’re going to go over the distal end of the device, and you’re going to backflush into the anterior chamber. And what you should then see is a reflux of fluid coming from the distal end. This is the percolation of flow that we want to see. It’s all about Poiseuille’s law. Based upon the length and luminal diameter we should have this nice trickle of flow that you get from the anterior chamber outside the eye. So we’re confirming patency. And then a watertight closure. That’s it, it’s as simple as that. So again, we’re trying to get a more controlled bleb-forming procedure and again I kind of consider this a little bit of a hybrid between doing a tube and a trab for me.
Where does the simulation kind of help? This is one of the SimuEYES. It’s nice because there is some rotation of the eye here, which is what you will do with the actual human eye during surgery. You’re going to mark again about three millimeters posterior to where you would think the limbus is. And I think this is the most important part and this is the step that you have to practice. Again, making that needle track into the interior chamber. Again, you want that wider entry into the sclera, it’s going to be a more narrow track into the eye. You’ll take the actual MicroShunt now and you’ll get a feel for how it is to grasp it with a non-tooth forcep. And how much give the device has. And you’ll want to then insert it double up into the track.
And again, sometimes you have to be a little careful, it can be a little bit more challenging to actually insert the tube, depending upon how you make the track. The reason I think the reason at the step is so important is that the three millimeter tunnel is rather long. And you’re going up the hill of the sclera. And if you stay too superficial, this tube will enter rather anterior, and be directed right at the cornea. So you can practice with the model here, trying to get a very level pass. And I think the key is when the tip of the needle gets to about the blue-gray line, you want to actually lift the heel of the blade and try to flatten out your approach. The other option is to try to take a slightly downward path through the sclera with the blade, which can be a little tricky because you may exit too posteriorly. But that’s where the simulation is going to help because it’s going to allow you to practice trying to get the right path into the anterior chamber, because you do not want these tubes pointed at the cornea.
So let’s see. This was my first MicroShunt implantation. You’ll see here, I’m going to make a pretty wide conjunctival peritomy. I do like a traction stitch place for most of my surgeries. Thought maybe not totally necessary here. Again, good posterior dissection making a nice pocket, here is our cautery. I’m going to apply the mitomycin next being careful to protect the leading edge of my conjunctiva. Once all the pledgets are in, again, I sometimes take that last pledget and try to have it sort of sit, as you see right here. Kind of where the distal end of the device is going to come out of the sclera. Remove all the pledges carefully, make sure you count them all. Rinse with BSS.
Now here’s the track. Here’s where I’m saying you want to stay deep and then lift a little bit right when you get into the blue-gray, and angle a little more posteriorly. We’re going to take then the MicroShunt, and we’re going to slide it right into the track. And the fin should sit perfectly into that little opening there and the sclera. Here’s where we’re priming the device with a BSS on a cannula. And again percolation of flow. Perfect. Bring the conjunctiva and Tenon’s up, making sure that you don’t catch the device with the Tenon’s. Some people actually close in two layers. That’s it. That’s how simple this procedure can be and that’s why many of us are excited for this new device.
I hope that is a helpful lecture there. I have 10 minutes here to kind of give you a run-through on the technique. But once again, I’ll take any questions later. But thanks, everybody, for the invitation to speak today.
[Malik] I have a series of questions. We’re going to try and go for about 25-30 minutes with some of the questions that have come in from the audience members. And this is really in no particular order. It might be good to just go through the panel and get an idea. Common question is what kind of gonio lens do we use? So maybe I’ll go on the screen here in front of me, it starts with Mike Greenwood. The question actually came in with the gonio lens you were using, which I believe is from Glaukos. Is that right?
[Mike] Yeah, the one I was using in the wet lab videos was just a disposable prism from Glaukos. The one I use in the OR is also from Glaukos, but it’s a reusable one. And I have a little clip on it, it’s called the Berdahl Stabilizer Ring from Storz. And I have no financial interest in any of those, but I like it because it elevates the prism a little bit, so if your hand gets heavy it doesn’t cause a lot of stria. So it kind of floats over the cornea. It does stabilize the eye so you can move it a little bit. And it also provides a little bit of space between your incision and whatever instrument you’re using, so that the prism doesn’t hit the instrument, and inadvertently move the stent up and down.
[Malik] Is the Berdahl Stabilizer usable for different gonio lenses or is it specific to the Glaukos lens?
[Mike] It’s metal, but it’s pretty flexible. So I would imagine that it can be modified and used on multiple prisms.
[Malik] Does anybody else have a?
[Mike] It’s reusable.
[Husam] Oh, it’s reusable.
[Malik] Yeah, I remember seeing it awhile ago, but I didn’t realize that’s what you were using on the Glaukos lens, or in the gonio lens from Glaukos. Anybody else have any tips for gonio lens? One you prefer over the other? Monisha or Leo?
[Leo] Yeah, I would say I use the standard Swan Jacobs lens, like I showed in the video. But occasionally, if you’ve got a patient who just can’t seem to fixate or hold their eye still, there’s an old lens from Transcend at the time. I think it was called the Vold lens, which has a stabilizer, or a fixation ring attached to it. And that can work really nice to help stabilize the eye. It was designed to implant side past. But if you’ve got an eye that just won’t stay still and you’re worried about causing more damage, working there in the angle, that can really help stabilize the eye.
[Malik] Great, Monisha, what were you going to say?
[Monisha] Yeah, I agree with Leo. I have used the Swan Jacobs for most of my cases. And anytime I have access to that Glaukos eye prism, I love it, because it has just such a nice, wider view as compared to a Swan Jacobs. So I think, especially, if you’re starting out, it’s really nice to have as much view of the angle as possible. Especially if there’s one area or clock hour of the angle that’s a little bit better suited for you to implant or do your MIGS on. Both of those seem to be helpful.
[Malik] Okay. Mike, I’m going to come back to you with another question. So you use a bunch of different devices, like most people on the panel. Which one should somebody start out with? (laughs)
[Mike] Yeah. (laughs)
[Malik] And why?
[Mike] Easy question. You know, if you’ve never done anything, I think it’s a little less stressful to use one of the devices that doesn’t have to place a stent. And the reason why I say that is what you learn from the videos and when you run into trouble, trying to regrab a stent that’s been misplaced. So I’d probably tell people to start with something where you’re not placing a stent and just get real comfortable with it. But from the first video, going through and just practicing can help. I guess my go-to when you’re learning would be the KDB.
[Malik] I would add to that and say that ECP is another really good option when you’re starting out. And it’s something that…I started doing ECP way before we started doing a lot of the angle procedures. And I thought just having that different flavor of what you’re doing inside of the eye was very helpful. Which leads me to a couple of questions for Jella. You did a great job on your lecture, a lot of good information. And some of the questions that came in, one is can you use ECP in angle closure glaucomas? That’s something that you’ve done? And do you approach things a little bit differently in those cases?
[Jella] Yeah, absolutely. Actually, I use ECP more on those angle closure patients than open angle glaucoma these days. There’s case reports on patients with a plateau iris syndrome who have a UGH due to the rubbing of a haptic, biohaptic, to the posterior side of the ciliary body after cataract surgery. You typically see that those people with the prominent plateau iris continue to have an angle closure even after the cataract surgery. It opens up a little bit, but it’s still narrow enough that it is still at risk of possible angle closure and a PIS after cataract.
I like adding ECP in those cases. I aim posteriorly, posterior side of the ciliary body to really retract it down, retract it posteriorly, to further open up the angle, and reduce the size of the ciliary body, as well, in those cases.
[Malik] How often do you combine an in-flow, out-flow procedure? If you’re doing ECP for in-flow, how often do you do an angle procedure?
[Jella] I actually often do not combine those procedures. I know it is a popular method. Because I feel like an angle surgery alone has a good enough IOP lowering in my hand, that I didn’t have necessity to add in ECP, which can increase the risk of inflammation post-op.
[Malik] Okay. So I have a series of questions for Joe and Husam when it comes to XEN and Preserflo. And I’ll start with you, Joe. The mitomycin question is a common one. And there’s a background story to that in the US, what we can use that’s approved by the FDA. Can you go into that a little bit? So why do you have to use a particular dose and then what dose do you ultimately use for either XEN or Preserflo?
[Joe] Sure. For our FDA trials, the only approved formulation of mitomycin C is the Mitosol kits. And the labeled use for that is .2 milligrams per ml and for two minutes. And so we use that on either two to four half moon soaked pledgets. I believe in the pivotal XEN trial it was two half moon pledgets and for the Preserflo we used four half moon pledgets. And that can work for a good number of patients. But I think, as all of us will tell you, it’s really all about individualizing the dose and the concentration depending upon that patient that’s sitting in front of you.
I’d say with XEN right now, and even when, probably when Preserflo is available, I probably will use it off label. I do like to inject mitomycin C. I think I know the amount of mitomycin C that’s being placed, I get a more diffused application, I think I get better posteriorly directed blebs. And I will typically use about 60 micrograms. So .15cc of the .4 milligrams. I inject it 10 millimeters posterior to the limbus before I start my first opening for the procedure.
[Malik] When you were doing the Preserflo work, how long were you keeping the pledgets in place? So it was the .2mgs per ml, but it was for two minutes.
[Joe] Two minutes, correct.
[Malik] I mean, those are the two nobs that are most important for us. The dose, the actual concentration and then the time. And you were sort of handcuffed for what you were doing with the initial Preserflo studies. I think people should look at the trial data with that in mind. That it’s going to probably be much different when it’s out there.
[Joe] 100%. And I think we all saw that with XEN. My XEN results got better when I started increasing the amount of mitomycin C that I was using. Remember, for both of these devices, we have very slow regulated flow. And pretty much any healing is going to jeopardize the success of these procedures. So you want as little healing as possible. I always joke around and say the best procedures, XEN, are the ones that are eroded through the tissue because the pressure’s perfect as it is. Because there’s no resistance.
[Malik] All right, we’ll go ahead and edit that out of the posted version.
(all the panel laughing)
I’m going to ask Husam a question that we probably both learned from Joe, which is the ab-externo. Using a needle and not the injector technique. I learned this, I remember talking to Joe about his technique and then coming back and trying it. I know Leo did the same on our service. But can you tell me, Husam, from your standpoint, do you like using the injector for ab-externo or do you like doing the Panarelli technique of not using the injector?
[Husam] Yeah, I actually, I really like not using the injector, to be honest with you. Because we’re so, many of us who have adopted XEN, are already very comfortable with placing aqueous shunts with a 23 gauge needle, and placing the tube in the anterior chamber. And we already know how to discharge the stent from the injector and handle it without the injector with forceps. It’s actually a very easy transition if you’re doing an open conj ab-externo technique. Needle tracks slip the XEN in and it’s very simple. And so the injector, actually, I hate to say it, it can be cumbersome. And so Joe was great to just get rid of it.
[Malik] Yeah, totally agree with that. In my hands, at least, it’s easier. But the one thing that can happen when you’re first starting out, and you’re going ab-externo without the injector, is if you go too slow or if the device gets wet, it becomes really hard to handle.
[Husam] And also, to be fair, you have to be very comfortable manipulating it with forceps because it’s so easy to tear, break, kink, all of the above. So it just requires, we’re all ophthalmic surgeons so we know how to be gentle.
[Malik] Yeah, right. And what we do and we’ve done this just a couple of times. Where we’re going back and forth, and I know Leo’s doing more of the XENs than I am, for sure. But keep the injector handy because if it does get wet as you’re trying to go ab-externo without it, you can put it back in the ejector and then do it that way. So let me go to Leo with a question. When you’re postoperatively, do you stop all the glaucoma medications or do you tailor to the specific patient? How do you handle that?
[Leo] Yeah that’s a good question, I think initially when we’re first doing goniotomy, you’d see a lot of pretty low pressures day one and you think things are great. And you’d stop them all. We started running into a few post-operative spikes, you get some steroid response, like any of these procedures. And I think it became more commonplace to keep at least one medication going even if their pressure looks good day one. If they’re still a little bit high, I may keep them all going. But as long as the pressure is down, I’ll keep one glaucoma medication on board at least to get them through that first week of QID steroids, where they’re more likely to get a spike coming up to the one-week visit. And that usually will blunt or minimize the incidence of that.
And then once you taper off the steroids, if they’re still doing well then we’ll take them off one by one and see, just sort of test the waters. But I think setting expectations is key with that because if you sell this to a patient as a way of getting them off medications and then you continue with it, day one they’re wondering what went wrong? Why is this failing? But you set expectations first and you say it may take a month to get them. And then things are much more smoother postoperatively I think.
[Malik] And I think this is something that comes up in discussions between all of the surgeons. There is some who really believe in just stopping every medication automatically because there’s a fear that you won’t remember to take the patients off their medications subsequent to that. So if you do start a medication or two after surgery, you always have to come back post taper off steroids and remember to try and wean them off those couple of medications. But I agree with the way that you do it, Leo.
[Husam] I think Leo’s point, just in general, is a very good general point about setting expectations. In general, I mean we do that with glaucoma surgery all the time. But with each one of these procedures it’s very important to give a patient a realistic impression of what might be coming in a month, two months, four months, just in general.
[Malik] Yeah, I made the point when I did the intro lecture to the session about letting the patient know that this isn’t just the cataract surgery, when you’re doing a combined. Because we’ve all had that patient who comes in post some sort of angle procedure and they’re like, you know I’m coming back a little bit more frequently versus my neighbor who had their premium IOL with no other glaucoma procedure. So setting expectations is extremely important.
I want to go with Monisha with a couple of questions here on OMNI. Or really any type of canaloplasty approach. So what OVD do you put in the anterior chamber, and what OVD do you put in the device, and have you experimented with that with the use of a different OVDs?
[Monisha] Specifically the device, it’s indicated to use a cohesive OVD, like Healon, for example. I typically will just put in the interior chamber, I use what I use during cataract surgery. For me it’s either PROVISC or AmVisc. And then to prime the device I will use what’s indicated, like a nice cohesive viscoelastic like Healon. And that does work pretty well. I sometimes have not had a certain viscoelastic available to me, so really I try to find whatever is the most cohesive as possible and let that be in the device itself. And whatever I have at my ready for the anterior chamber is fine whether it’s just visco, because we ran out of our cohesive visco, cohesive OVD, those tend to work just fine. And I haven’t really had an issue.
But it is nice when you have something cohesive because it really just helps, one, maintain stability of the chamber, and two, you want to maintain the patency of the distal collector channels. So like you said, Dr. Kahook, when you go in and check the episcleral venous system with a little bit of BSS at the end of the case, I always tend to do that. And I found that when I had the cohesive viscoelastic that’s primed with the device, I tend to see that blanching effect much more often. I tend to stick with something cohesive.
[Malik] That’s good. And because Monisha called me Dr. Kahook, I expect every one of you to call me Dr. Kahook for the rest of the session.
Next question is for Jella. Do you do angle surgery before the cataract surgery or after the cataract surgery?
[Jella] I tend to do angle surgeries before the cataract. Just because the cornea is more pristine, the eyes a little firmer. I feel like I get a better view, a clearer view of the TM. And as you show in your presentation, there’s really not much of a difference between either the wideness of the angle, either before or after. There’s a certain exception, if the patient has a really high lens rise, AC of 1.5 millimeter, then I would do it afterwards.
[Malik] Okay and Leo, you’re the lead author or senior author of that paper, and he comments of what we found in that work?
[Leo] We took Imaging before and after phaco of the angle, putting the gonio lens on and just seeing what kind of you did you have? Because, I think some surgeons are pretty particular in their preferences, but we really found no difference. We had masked observers look at the images before and after phaco. And these weren’t the most complex cataract surgeries, so it’s going to be a really dense lens that may impact your view. But for most combined surgeries, your view is going to be the same. The one thing that may help you after cataract surgery is that you can get a little blood reflux in the angle. So if it’s a really blond angle, where there’s not a lot of pigment, the heme reflex there will help highlight the TM for you and really show you the runway of where you’re targeting. So that’s one advantage to it.
[Malik] That’s a great point, yeah. One thing that, and we’re getting towards the end of the Q&A, because we don’t want to go too long with these. Especially since I know a lot of people listening in probably have other duties to do, a lot of people calling in between clinic duties. So this is a general question and I’ll try to call on a few of you. One thing that happens when we talk about angle surgery or when we mention MIGS, people think about mild to moderate combined with cataract surgery automatically. They’re thinking of that type of patient. But I think we have a wealth of data and I know our collective experiences show that that’s not just that small category of patients. We can do standalone, with actually anything that we covered today can be standalone, quite effective. Or we can do the more severe disease patients. So maybe Joe? Do you do MIGS surgery angle procedures in patients who have severe disease? And how do you think of that?
[Joe] Yeah, so what I think it’s a great point. I do, I think it depends on what the patient’s goals are. It depends upon what their pressure is, and the fields, and whatnot. I agree with you, there is this teaching that this fits this bucket, this fits that bucket. I think you can do an angle surgery in patients with more severe disease and I think you can do some of these subconjunctival MIGS procedures in patients with mild disease on a handful of medicines who you want to stop this disease earlier. I think yes on both sides.
[Malik] Yeah. And Mike, what do you think of that? So the severe patient thats’ coming to you whether they have a cataract or not would you consider angle surgery?
[Mike] Yeah, I do. And almost so there’s two separate things here. So if someone’s got really high eye pressure what we’ve learned is that angle based surgery, the higher the pressure starts the more lowering you’re going to get. And a lot of these devices that we talked about they all kind of settle in sort of the same area. But if you’ve got someone who’s pressure is 40, it doesn’t mean you have to go straight to a tube or a trab, you can try angle based surgery on that, and you’re going to get pretty significant lowering. You may need to do something more somewhere down the line, whether it’s add medications or more surgery. But you can start with an angle based or a MIGS based procedure or something small.
And then on the severe patient, severe visual field loss. If they’ve got a little bit of time, meaning like I don’t have to go straight to a tube shunt, they don’t have any neovascular glaucoma or something, I’ll always try and MIGS first and just see what I can get. Before making that next step to the big bad glaucoma surgeries, as I call them. So yeah, I think it’s worth giving a shot. Again, with the proper informed consent that you might have to do more. But if you can save that, or push that, or kick that can down the road a little bit, you’re doing the patient of favor.
[Malik] Yeah, and like Husam brought up about setting expectations. So if you take a patient who has severe glaucoma you can set the expectation that you’re going to do angle surgery to save them for a bleb, but there’s a 50-50 chance, let’s say, that they’ll still need to go to a trab or a tube. And I’ve never explained it that way to a patient where they said, no, just let’s just get the bleb right away. (laughs) So I think if you set expectations that way then things tend to work out. Husam, so do you place a XEN sub Tenon or subconjunctival? And does it make a difference to you?
[Husam] You know, I’ve tried a few different things and now that I typically do an ab-externo open conj approach, I am placing the XEN sub Tenon’s so that it’s laying nicely against the sclera, making a nice large posterior pocket under the Tenon’s. I was doing some experimentation with actually removing Tenon’s. And I found that my distal end of my stent was sort of rubbing up right up against the edge of my Tenon’s incision. So it was almost like I was inviting Tenon’s to get into the lumen of the stent. So by just not doing that anymore, I’ve actually achieved some better pressure control and reduced needling.
[Malik] Okay, I wouldn’t have thought of that. Joe what do you do in your XEN cases?
[Joe] I’ve been and continue to be just open conjunctiva sub Tenon’s. I think it’s just consistency and it’s reproducible. I think the subconj approach is very nice when it works well, but a lot of times it’s either a home run or a strikeout. And I think that’s the hardest part about the subconjunctival placement is that it’s just very hard to get consistent results every time. So that’s why I like the sub Tenon’s placement.
[Malik] Okay. Jella, do you ever repeat ECP?
[Jella] No, I do not. No. I didn’t have to because you can see the endpoint when you’re in there which is this contraction and whitening of the tissue. I haven’t had to repeat.
[Malik] Yeah, it used to be that when I first started out doing ECP, which was a long, long time ago now. We would talk about doing 180 and then potentially coming back and doing another 180 or retreating the 180 and doing the rest. Kind of like the old teaching for an ALT or SLT. But a lot of people do 300 or 360 going through a second incision. And rarely do most of us go back and do another ECP. We’ll typically move to another type of procedure. So I think it’s just something good to know for people starting with ECP.
We’re coming towards the end of the time that we had allotted for this. And what I wanted to say and just take a couple minutes here, is that when people are starting to do angle procedures, you’re going to hear a lot of dogma. You’re going to hear a lot about you need to start with this, you need to start with that. Or you have to do three different things in order to serve your patients well. You can’t just pick one thing and learn it well. And I think, try and avoid some of the dogma and learn by talking to several people. Because we all have our own habits and our own likes and dislikes.
I think for a lot of what we’re doing, bread-and-butter angle surgery, a lot of the devices that we just heard today we are going to do about the same. They’re all going to serve the patient very well especially when it’s combined with cataract surgery and mild to moderate disease. A lot of these are going to get you really good IOP lowering with a decrease in medication. But we have our likes and dislikes based on our training, some of the economics also factor into it. And I think a lot of the panelists that are here, pretty much all of us, would be happy to answer any questions. We’re really easy to find on social media or our emails are on a lot of our publications. So feel free to reach out to us.
I also want to thank all of the companies that helped out. All of the companies that you saw in the videos today provided devices. Several of them also provided some of the simulation eyes. So this is a really group effort, not just on the physician part but also on the company part. And of course, lastly thanking Cybersight and Orbis for allowing us to put this together.
We all get to see each other, we’re all friends, and we haven’t seen each other live, well I get to see Leo, I guess, because he’s my neighbor. He’s like that way. (laughs) Although he’s in the office right now. But the rest of you, we don’t get to see that much so it’s nice to see your faces and to do an educational session, where I’m a hundred percent sure we also learned something from each of the lectures today. So thank you very much.
And for everybody else watching, this is going to be posted online on Cybersight, so you can go back and listen to the pearls, and really learn before you do your first cases. So thank you, everybody, and have a good rest of your day.
March 25, 2021
2 thoughts on “Lecture: Surgical Simulation & Minimally Invasive Glaucoma Surgical Approaches”
Excellent discussion. One comment why choose a MIGS for severe glaucoma patients is the lesser incidence of wipe out involved particularly if the field defects are closer to fixation where trab becomes slightly risky. MIGS serves as a good intermediate option and helps achieve a low teen IOP with additional medication. At the end, helps reduce IOP or reduces the number of medications. I am happy with results with iStent W in severe glaucoma.
excellent. very informative. thank you.