Lecture: Optimizing Your Glaucoma Filtration Surgical Results

This webinar will be largely case- & video-based discussions on the planning, construction, and completion of a trabeculectomy to optimize patient outcomes. The speakers are at all levels of experience from current fellows to professors and talk about the “pearls”/tips that they have learned throughout their ophthalmic careers.

Moderator: Dr. Leon Herndon


[Leon] Hello. Happy Saturday morning, or afternoon, or evening, wherever you may be from around the world. I’m Leon Herndon, Professor of Ophthalmology and Chief of the Glaucoma Division at Duke University Eye Center. And I’m honored to serve as moderator for our first Duke Glaucoma Surgery Series Program. The Trabeculectomy is Not Dead: Optimizing Your Glaucoma Filtration Results.
We know that worldwide the number of trabeculectomy procedures are going down. But we also know that there’s no other procedure that will lower the intraocular pressure as low as trabeculectomy can. We’re concerned that the next generation of glaucoma surgeons will forget how to do a trabeculectomy as other surgical procedures are being emphasized in many surgical training programs. So we see today’s program as an opportunity to teach some pearls for success with this important procedure.
So the plan for today’s program is to break down trabeculectomy surgery into its individual steps and to share expert opinion with you on various tricks that have led to success in our hands. This program is being recorded and will be available for attendees for future review. I want to thank Ocular Therapeutix for their support of this program.
Now, I would like to introduce our faculty and fellows for today’s program, all of whom have ties to Duke. We have a collective 147 years of experience doing trabeculectomy surgery. First for our guest faculty. Jonathan Myers did his glaucoma fellowship at Duke in 1996 and 1997. And in fact, he, along with Chuck Yang, was my first fellow at Duke. Jonathan is Chief of Wills Eye Glaucoma Service in Philadelphia, Pennsylvania. Welcome, Jonathan.
Gayle Howard did her glaucoma fellowship at Duke 20 years ago. She has a practice at the Eye Physicians Medical/Surgical Center in San Diego, California since 2007. Welcome, Gayle.
[Gayle] Thank you.
[Leon] I want to also introduce Pratap Challa, who is one of my partners in crime at Duke. He’s Associate Professor of Ophthalmology at Duke. Welcome, Pratap.
[Pratap] Hi.
[Leon] Divakar Gupta is Assistant Professor of Ophthalmology at Duke. Welcome, Divakar.
[Divakar] Thank you.
[Leon] Stuart McKinnon is Associate Professor of Ophthalmology at Duke. Welcome, Stuart.
[Stuart] Thank you, Leon.
[Leon] Henry Tseng is Associate Professor of Ophthalmology at Duke. Welcome, Henry.
And Joanne Wen is Associate Professor of Ophthalmology at Duke as well, welcome, Joanne.
[Joanne] Thanks, Leon.
[Leon] We have two stellar fellows with us today, two of our five fellows. Ang Lee will be finishing her fellowship in another two weeks. Ang’s going to Cleveland Clinic in Cleveland. Welcome, Ang.
And Minjy Kang. Minjy also will be finishing her fellowship with us in a matter of weeks. And will be going to Northwestern where she’ll start her glaucoma faculty position. Welcome, Minjy.
At this time, I’d like to turn the program over to our chat master, Divakar, to give details on the Q&A feature for today’s program. Divakar.
[Divakar] Excellent. I was going to say good afternoon, but I don’t think that’s accurate, we have an international crowd today. I was going through the registration lists and people spanning Africa, the Americas, Europe and Asia. So good afternoon to our friends in America, South America, and Central America, and Canada. And then good evening to our friends in Asia and hopefully we don’t put some of you to bed.
I’ll be mostly monitoring the question/answer features, depending on what platform you’re on. In the toolbar of the Zoom window there’s a Q&A section that you can click on that and all the attendees can write their questions. As they get answered, either live or in the feature we’ll mark them off and so there’s an answer tab in the Q&A feature. If you’re having any problems, you can send us a chat, but we’ll be checking the chat less frequently. So we’d prefer if you could use the Q&A feature.
[Leon] Thanks, Divakar. To start off, we’re obviously all dealing with this COVID pandemic. I want to start off by asking how different practices are dealing with their glaucoma patients as they ramp back up to speed.
Gayle, how has the COVID pandemic affected your glaucoma practice?
[Gayle] Well, in general, in San Diego, we have been fairly spared in the sense of a fairly low percentage of positive cases. But in my region of San Diego which borders on Mexico, we’ve had the higher percentage positivity in our area and our hospital has been at its limit a couple times. For our practice, early on, we immediately started calling our older patients in the beginning and letting them have the option of telehealth, trying to postpone their visits. And then there was a period in the middle where we actually closed completely and were only open for emergencies. And we alternated our staff and doctors so as to not have any one group that was exposed that then couldn’t be replaced by another group.

And then about a month or six weeks ago, we started slowly adding back. And we’re at about 50% capacity now which lets us have time to do very thorough cleanings and keep social distancing in place in the office. For a lot of our patients it’s the very first time they’ve actually come out is to come see us at the office. So we’re trying to do everything we can with screening before they come, when they first get here, and of course for our staff. And we’ve been fortunate so far but we’re trying to maintain that high level of precaution.
[Leon] What about you Jonathan at Wills?
[Jonathan] We did many of the same things so well described by Dr. Howard. The other thing we’re doing now that we’ve reopened, because we actually did have a fairly significant peak, is we’re following a sort of one patient, one room, one tech approach. Where each patient has very limited exposure to other people in the office. We check people out and make their appointments from the exam room. The technicians, during the down time, were all trained in making scheduling appointments. And the technicians also in this way meet fewer patients.
It’s a much quieter process but the challenge here is to keep the waiting room empty is our main goal. It’s a challenging situation for everyone. I think everyone’s unique situations may lead to unique solutions.
[Leon] I’ll ask Divakar to summarize the experience at Duke. Divakar?
[Divakar] I think our strategy has been similar to the strategies laid down in San Diego and at Wills. We primarily, now that we’ve opened up, have been trying to emphasize social distancing and cleaning. So we’re cleaning all our rooms, patients are getting temperature checked and asked to wear a mask, are really required to wear a mask. And we’re thoroughly cleaning our lenses, our visual field rooms, and exam rooms.
One other thing that we’ve tried to do is whenever possible, we’re trying to use telehealth. During the peak of the pandemic, when we were only seeing urgent patients, as mostly in late March and April, and we weren’t doing elective surgery. We were really doing a lot of our encounters on telehealth when possible. And that’s spearheaded some innovation in our department and in the future we hope to have more creative workflows to promote social distancing and encourage telehealth.
[Leon] One thing we’re seeing that’s unique to this pandemic is getting visual field defects from patients wearing masks. It’s been reported on AJS Med and I’ve surely seen it in my practice. It’s been important for us to have our patients have their mask taped to their nose, otherwise they fog, and fog up the lens, and cause an artificial defect. One of many things we’re having to do differently now in our practices.
Now I’ll turn the program over to our fellows who will start out with some slides about the history of filtration surgery and then we’ll organize the various surgical clips of the different steps of trabeculectomy surgery. Ang, Minjy?
[Ang] Can you see my screen and my slides? Thank you, Dr. Herndon. I was going to start with some background slides and the historical perspective in trabeculectomy. Glaucoma filtration surgery is performed to provide an alternative route for aqueous drainage from the anterior chamber, and past the pathologic obstruction in the trabecular meshwork, to a space underneath the conjunctiva known as the filtering bleb.
The desired result is to decrease IOP to a lower level that would halt progression of the optic nerve damage and vision loss. Typically, trabeculectomy is a surgical management option after medical and laser treatments have failed. Many variations in technique have been developed throughout the years. Let’s take a look at the historical perspective and review some of the major milestones that led to what trabeculectomy is today.
Von Graefe made contributions to the field of ophthalmology in the 19th century. He distinguished between three classes of glaucoma: acute, chronic, and simple. And he was the first to use iridectomy to lower intraocular pressure. So when he first described iridectomy as a treatment for acute glaucoma, it was also performed for seclusion of the pupil and the complete posterior synechiae in secondary glaucoma. His dissemination of the technique established iridectomy as an important treatment which we still use today for angle closure.
Louis de Wecker was a French ophthalmologist who introduced the interior sclerotomy in 1858 as a treatment for chronic glaucoma. In this technique, de Wecker made a full thickness scleral incision, one millimeter posterior to the limbus. And this was the first procedure to make a filtration cicatrix, through which aqueous fluid might leave the anterior chamber.
Many modifications were introduced after de Wecker’s sclerectomy. Intraocular drainage via a pathway between the anterior chamber and subconjunctival space became a focus of glaucoma surgery innovation at the beginning of the 20th century. The original type of limbal fistula involves creation of a direct opening through a full-thickness cut at the limbus. And in 1906, LaGrange described the technique in which a full-thickness limbus incision was made and then a piece of tissue was then excised from the anterior lip of the wound to create a fistula. Three years later, Holth modified this technique by performing the sclerectomy with a punch.
One way to minimize the complications of the full-thickness sclerectomies was the development of the partial thickness corneal-scleral flap over the fistula. This was developed by Dr. Sugar in 1961 and later popularized by reports of John Edward Cairns. Both authors described this new technique as the trabeculectomy and it has become the golden standard of filtration surgery ever since.
It was originally thought that the major mechanism of action of trabeculectomy was aqueous flow through the cut ends of the Schlemm’s canal. Subsequently, studies however show that there are fibrotic closure of the canal at its cut ends, in monkeys and human eyes after surgery. It was then discovered that the most successful cases of trabeculectomy have a filtering bleb. And the amount of aqueous in the filtration area correlated with the success of the procedure. So adjusting that external filtration was the main principle mode of IOP reduction. Flow could be either through or around the partial thickness scleral flap.
Scarring is the enemy of trabeculectomy. Various forms of wound healing modulations were later developed to combat the eye’s natural response to scar formation. In 1965, Cohen suggested beta irradiation to the surgical site as an adjunct in Black patients. The potential complications for beta irradiation including conjunctival and scleral necrosis and cataract formation were the main reasons for its abandonment.
Post op steroid have been widely used since Dr. Sugar described their effect in filtration bleb. And Gressel described the success of filtering blebs in monkey eyes that received subconjunctival 5-FU. Dr. Chen in 1990, found that mitomycin C, when used in conjunction with filtering surgery enhanced bleb survival. Mitomycin C is an antineoplastic antibiotic isolated from Streptomyces caespitosus and it acts to inhibit fibroblast proliferation from Tenon’s capsule. And has become, obviously now, the gold star the main method for which we prevent fibrosis.
The perfect bleb that is most often associated with a good IOP control is avascular with numerous microcysts. And are either low and diffused or more circumscribed and elevated. There are a couple of well-described established bleb grading systems to describe the bleb architecture. The Indiana Bleb Grading System utilizes descriptions of bleb height, horizontal extent, vascularity, and seidel leakage. And according to Moorfields grading system, the bleb is characterized by different zones, by three zones and with respect to height and vascularity in the central bleb, peripheral bleb, and non bleb.
At this point I’d like to hand over to my co-fellow, Minjy, and panelists, to start discussing some of the preoperative considerations that would help enhancing and achieving the perfect bleb.
[Minjy] Thanks, Ang. Before making the first cut in pursuit of the perfect bleb, there’s some factors to consider. Such as the status of the conjunctiva, whether or not to do combined surgery, and patient factors. If you could click forward for me, Ang.
As far as the conjunctiva, some things to consider are whether or not the patient might need a preoperative drop holiday or steroids prior to surgery. In terms of combined surgery, what the lens status is and whether you’re going to combine it with a cataract surgery. And of course patient factors in terms of whether or not you want to stop anticoagulation if the patient is on it, the ability of the patient to actually attend follow up visits, and the ability of the patient to be able to physically put in frequent steroids that are necessary after the procedure.
So I’ll hand it over to Dr. Herndon.
[Leon] Yeah, Minjy, Thanks for starting this out. I think it’s really important to hammer this home. The types of things we’re looking for when we first see the patient. Gayle, can you expand a little bit further on what you’re looking for when you assess the conjunctiva?
[Gayle] Sure, of course when you get to the operating room, you’re able to identify a lot more details about the conjunctival tissue that you’ll be working with. But prior to that in the clinic, you can assess from both the history of prior surgeries that might affect the conjunctiva, both prior glaucoma surgeries or possibly retinal or pterygium surgeries. As well as on examination, what appears to be the status of the conjunctiva. And you can even test it with a wetted q-tip, usually wetted with anesthetic, to try to move around the conjunctiva in the area that you’re planning for your surgery to see whether you have mobile conjunctiva, and whether it is fragile or it appears to have some substance to it. Also, you could be looking to see whether the conjunctiva appears to be inflamed. And if you think that’s related to current medication usage, you could consider a drug holiday, sometimes even substituting for a topical medication with an oral medication temporarily. And you might even want to suppress inflammation preop with steroids, either a short course of prednisolone or a slightly longer course of a weaker steroid.
[Leon] Thanks, Gayle. Henry, anything else to add?
[Henry] I agree with everything Gayle said. With the drop holiday, that’s something that’s very important because most of these patients all pretty much are on maximum meds, four, five different eye drops with really injected conjunctiva. So it’s nice to get the conjunctiva to be nice and quiet. I may or may not use steroids. Because any additional drops you add is going to really drop the compliance. So they may end up using steroids and they’re not using their glaucoma meds. And sometimes you’ve got to be careful because even though they might be scheduled for surgery, they may get delayed or rescheduled. And they might be steroids for weeks, even up to a month. So be careful there too. Especially recently with all the COVID rescheduling.
One thing I would like to add, also, is in addition to everything Gayle said, also it is a good time to look at how the orbit looks. How the eye sits in orbit. If there’s a huge orbital ridge, or the eye is very sunkun, that is also an important consideration, especially if you want to look at your approach. Whether it’s fornix or versus limbus based approach. And I think there’s going to be a discussion on that much later.
[Leon] Thanks, Henry. So Jonathan, many of our patients who have trabeculectomy surgery also have visually significant cataracts. What is your thought process involve with determining to do cataract surgery at the same time or not?
[Jonathan] Complex discussion and I’ll try to be brief. I think there are a lot of factors to consider in terms of the patient’s current lens status and acuity, and likelihood of having progressive cataract. I think for some eyes that have shallow chambers it can really help the postoperative management to have the greater space of the lens being gone. But at the same time, if you decide to do a combined procedure, you have to take into account that published by Frank Cashwell and others, even back in 1999. For every 10 points of pressure reduction, it’s about a half diopter of potential change in refractive effect. So it helps if you know what your pressure is going to be after the trab, as you adjust your lens calcs.
Further, there’s the whole discussion about toric IOLs in this day and age. And if your trab technique is not rock solid on astigmatic effect, that can be a zone you may not wish to get into. And then I guess I would have to say that if I think in my practice if the patient needs a trab, I think they don’t need a multifocal lens. I know some people do multifocals in glaucoma, but I think if you have real glaucoma, the visual quality issues of multifocals may not be in some patient’s best interest.
[Leon] Thanks, Jonathan. Anything else more to add, Divakar?
[Divakar] I think that’s an excellent summary of the things that I think about when I’m thinking about a combined procedure. Certainly, my preference is in situations that a patient’s medically controlled, if it’s possible to do sequential procedures, such as a cataract and a minimally invasive surgery prior to a trabeculectomy, that would be preferred. But many patients need a combined procedure.
A couple things that I think of during my surgical planning is in patients that may have a lot of cyclotorsion, I’m marking at six o’clock so that I know where to orient my trap flap. I also think about where my paracentesis sits. I’m a right handed surgeon so I notice when I operate on patients’ right eyes, sometimes my paracentesis is near where my conjunctival sutures or flap may be. So I am just more cognizant of that. And then I do suture my main wound. I do two side surgery, operating the cataract surgery temporally, so I do suture that would before I inject mitomycin. And I think that also helps stabilize the anterior chamber during the trabeculectomy.
[Leon] Thank you, Divakar. So Pratap, talk to us about the patient factors in addition to what’s listed there that you consider before trabeculectomy surgery.
[Pratap] A couple things. I guess we have a few that are here, we can start with those. Anticoagulation. You have to be careful in these patients who are on anticoagulation, particularly with agents that really are pretty potent like Coumadin and some of the newer anticoagulants. The problem is not just the problem at the time of surgery, but it’s the after surgery care of these patients as well. The difficulty in controlling patients, what their activities are after the surgery is done. If they strain, stress, pick up things, they can really be at increased risk for subcortical hemorrhage. And those become very difficult to control in patients that are on anticoagulation. Has to be a patient that’s very compliant who’s going to follow your directions. But if you have any question about that, it may not be the best procedure on a patient on anticoagulation.
Also, the ability to follow up, it’s important because we do do a lot of post op management in these patients, in terms of adjusting whether we want to cut sutures, adjust the steroids, even potentially use quite a few regiment therapy in the post op period. So they really need to be able to follow up. And if the patient’s not going to follow up, again, this may not be the best procedure because those patients really need to, the long-term success of trabeculectomy really depends on early post op care.
And also the ability to use frequent steroids. Sometimes some patients that just can’t either mechanically have difficulty using drops or don’t have anyone to assist them. Sometimes depo steroids can help in these patients as well.
[Leon] Stewart, are there any other factors that you would consider?
[Stewart] I think the factors that we used to consider in using mitomycin still hold. Patients tend to scar down more if they have uveitis, if they’ve had prior surgery in that area, if they’re young, if they’ve had neovascular glaucoma And potentially raises a factor, you might want to ask about prior dermal surgery, whether they had formation of keloids, And you may also want to assess the amount of Tenons. As Gayle mentioned and the slit lab, to see whether you need to do more tenonectomy if they have very robust Tenons or perhaps if they have very little Tenons to take super extra care about handling the conjunctiva.
[Leon] Do any of the other panelists have anything else to add? This was a very important slide to make sure we assess all factors when it comes to starting this out with a good result.
[Joanne] Yeah, Leon, I have just a couple things to add. I think something that’s really important to discuss with a patient is the long-term infection risk. And their situations and risk factors for having infection. So if I have a patient who swims a lot in fresh water and that’s a huge part of their life, a trabeculectomy may not be something that we consider a good surgery for them. Somebody who really wants to stay in contact lenses we’ll have a discussion about long-term infection risks related to that. When I was in Washington, and here too, farmers who are in a lot of dusty, dirtier environments. We think a little bit about that. Especially if they’re on the younger side and they have a lot of years to live with that bleb.
[Leon] That’s interesting. I tend to agree when it comes to contact lens wear. Not a lot of my patients wear contacts. But the literature’s all over the place when you look at the risk of bleb infection related to contact lenses. Especially soft contact lenses. If at all possible, I do agree, I try to have patients come out of their contact lens. And tell them that they may not be able to go back to them.
Also it’s important to have a discussion with patients that this might be their last surgery. Now, we’re going to give you pearls on how to have success, but we have to be realistic. We’re not going to show you how to do 100% success, we would love to give you that. But let patients know that this might not be the last procedure, but also give them hope that there are other future procedures if needed.
[Divakar] There’s a nice question that came in on the chat for Dr. Howard and Tseng, “How long should the drop holiday be knowing that the IOP will rise after stopping meds?”
[Gayle] And that actually is going to lead into one other comment that I wanted to make. Usually I would say not for very long. When I have had patients with intolerance of medications, I usually advise them that after stopping the medication they’ll notice a very significant improvement. Usually around two weeks. And if I bring them into the office, I can detect a difference in their inflammation at that point. So I probably would not go beyond two weeks. And also I wouldn’t want to introduce them to either the prolonged course or the steroids, or perhaps the oral medication and the side effects that go along with that, for much longer than that as well. And I would reinforce the idea that if the surgery’s going to be postponed, they need to be revisited and the plans need to be changed.
The other part that I was going to mention is that if you know going into surgery that the patient has a fairly high pressure, meaning probably in the 30s or higher, I also advise the patient and I make plans that I’m going to step down their pressure very early on in the surgery. And I may even use IV medications to help so that during surgery we’re not going to have a drastic drop in pressure. We’re going to try to step that down to just create the most safe situation we can.
[Leon] Thank you.
[Henry] I was just going to add that it really depends on your clinical judgement. But typically one week most people go out. And don’t forget when you do a drop holiday, typically you also add steroids. And that combination is fairly deadly, so definitely need close follow up.
[Leon] Any other questions, Divakar?
[Divakar] Not yet.
[Leon] Okay. All right, Minjy, let’s go to the next slide.
[Ang] We can move on to actually talk about the different steps in trabeculectomy. Starting with a conjunctival incision. We have a couple videos here. The first is a limbal based approach. This is Dr. Challa’s technique. I will ask to see if Dr. Challa could share your approach here.
[Pratap] Sure. I guess this is a more traditional approach here. You can see the conjunctival opening here is about eight to 10 millimeters posterior to the limbus here and balloon the conjunctiva up with local anesthesia. I don’t block any of my patients. And then dissect down through Tenon’s and then try to keep the conjunctival wound as minimally wide as possible, usually between four to five millimeters, so that then the closure will be as small as possible. Then dissect forward, as you can see here, up to the limbus, disinserting Tenons as we go anteriorly. Then we will cauterize here shortly the vessels. As you can see here, we have to extend it a little bit as we’re doing there. And usually trim Tenons trying to leave the conjunctiva as small opening as possible.
[Leon] Gayle, you also do a similar technique. Can you address your approach?
[Gayle] Yes, I do a similar approach where I try to keep the conjunctival incision small. And I do cut the Tenons at each of the edges of that wound more anteriorly to release that tissue to make that a little bit easier and not have quite so much tissue that has to be reflected back in order to then do your scleral flap dissection. And I’m looking at doing this technique in more of the situations where I feel like there may be difficulties of healing at the limbal edge.
[Leon] Thank you. Okay, Minjy or Ang?
[Ang] And we’ll move onto the next one. Minjy will talk about the different, especially for beginner surgeons, understanding what limbal based and fornix based really means. Can be confusing so, Minjy will talk about the anatomy of approach in her paper right here.
[Minji] Yeah, so Dr. Herndon was mentioning that he really switched from a limbal based to a fornix based approach based on this article by Peng Khaw and colleagues from Moorfields. And just to review, this is a diagram from the paper. When we’re talking about a limbal based flap, or incision, it means that the incision is actually in the fornix. So the base of the opening is in the limbus. Basically the bottom two pictures shown there are demonstrating a limbal based approach. And then the top two pictures are showing a fornix based approach where the incision is actually at the limbus and they’re showing, also, the application of sponges there are well.
This paper was a retrospective, non-randomized case series of 37 patients, and all these patients were under the age of 30 in this case. And they showed that the risk of cystic bleb formation was higher in the limbus based compared to the fornix based. Higher in the trabs with an incision in the fornix as opposed to the limbus. And there’s also a higher rate of late hypotony and bleb-related infection with the limbs based trabs.
And if you click to the next slide, Ang. You can see this is a photo from the same paper, just demonstrating the difference between the two. On the patient’s right eye you can see the right eye has had a fornix based incision at the limbus. And he has a nice diffused bleb. And then in the left eye, the bleb with the more cystic appearance and also had an episode of leakage and blebitis, that was a limbal based and so the incision was performed in the fornix.
[Leon] Let me stop there because this is important. Because I did change my approach to a fornix based surgery based on Sir Peng Khaw’s paper and others. But also, before, I was using only one sponge. And what Peng showed, as we’ll show with the further videos, that the more you can spread mitomycin, the more diffused and less cystic bleb that you’ll have. Any other panelists? What was your impetus for changing approaches if you did?
[Pratap] I’ll speak, because I really haven’t changed-
[Leon] You haven’t changed, Pratap!
[Pratap] This is a good point, because one thing we teach all the trainees here is when you read a paper, you have to ask questions about the paper. So one is, of course is, is the study powered adequately? To answer the question here. This is a retrospective review, can’t really answer that question. What’s the inclusion/exclusion criteria? And of course, does the patient population match your own? So these are mostly young individuals, European, doesn’t really match our population that we see here quite as much. But the one thing that I thought was really interesting about this paper when I came out a long time ago, was that they had a really high rate of bleb infections amongst their limbus group. And I think if I remember right, Minjy you may have to correct me on this. It was like 20% or something like that? Four out of their group and they had zero in the other group.
[Minjy] Yeah, it was three out of the limbal based and zero out of the fornix based.
[Pratap] And that is such a high rate. If you look at all the studies that are out there. The average rate of bleb infection is about 1% per year, in most of the studies. That was kind of odd to have such a really high rate of infections in that group. And the other thing too about that, is that if you look at the Cochrane Data Base, try to do a meta analysis of this. I think two or three years ago I think they published it. I can’t remember if it was AGO, but they didn’t really show much difference. Harry Quigley’s group didn’t show, it showed a higher rate of cystic bleb formation, maybe if I can recall it correctly, maybe a little bit higher rate of bleb leak. But not that much difference in terms of a limbus based versus a fornix based.
That’s why I really haven’t changed it. It’s relatively predictable. Every now and then I’ll do a fornix based one if they’ve had previous, particularly retina surgery in the past where their conj is a little more scarred anteriorly. And it’s not so scarred posteriorly. Sometimes I’ll do it that way, but yeah. I wasn’t really compelled to change the way that I do my procedures.
[Divakar] There’s a couple comments on the chat about this. One, Dr. Quigley’s actually on the call and he added that contact lens wear after trabeculectomy raises infection risk by 5X. And he provided a reference that you can all see in the Q&A. Also someone asked, Jesessy asked, “What is explanation for the higher rate of bleb-related infections in limbal based?”
[Pratap] Yes, Jesessy, that’s what my point was, it’s really very high in this group. But I think the bleb infection are primarily related to avascular blebs, which cystic blebs are avascular blebs, any sort of bleb leak, if you go by looking at generally at what’s out there in the literature.
[Jonathan] Those are great points, Pratap, I have two thoughts. I switched to fornix based because I was unassisted in a surgery center and switching to topical anesthesia. I just found it was easier for me to do the surgery with less fumbling and manipulation of the tissue and the patients were more comfortable. Also being the simple guy that many of you know me to be, I really prefer to talk about anterior incisions and posterior incisions. Because then I don’t have to stand on my head to figure out what we’re talking about. I know that in 20-some years in the business I should have figured this out. But it’s an alternative way to talk about things. But sometimes it’s a bit more intuitive.
[Gayle] And I would just comment, Jon, exactly. In a private practice setting, I most of the time do not have an assistant with me that I would feel comfortable having handle the conjunctiva. So in most of the cases I am using a posterior incision or a fornix based. But as I mentioned again, with Dr. Challa’s technique, that there are times when I use that as well. So it really depends on what the conjunctiva looks like, what your exposure looks like, and then the other factors where you’re concerned about later infection, the age of the patient. There’s many factors that go into making that decision of which incision’s best.
[Pratap] It’s not my technique. Actually, Leon taught me that technique back when I was a fellow two decades ago.
[Stuart] Another consideration is with a limbus face or posterior incision, sometimes you see the classic ring of steel of scar tissue, you go back and do a bleb needling and you really try to plow through that scar. And you don’t see that with a limbal base, excuse me, or an anterior incision with the fornix based. And typically, hopefully, get a more diffused, lower bleb with the anterior incision.
[Leon] Okay, let’s go on to the next slide.
[Divakar] Dr. Quigley agrees with you, Dr. McKinnon.
[Ang] And this is Dr. Herndon’s technique of the fornix based anterior incision.
[Leon] Yeah, I use a small peritomy, I think this was an Ex-PRESS shunt surgery and I inject lidocaine, tubes of epinephrine anteriorly for this anterior, fornix based dissection. Again, I found that, so the differences between the two, I’ve found they’re more likely to have a leak with this approach than if you take a posterior approach as Pratap does. So that is one difference that I’ve seen with this technique. Joanne, can you comment on your approach to anterior surgery?
[Joanne] Yeah, sure. I do mine very similar to you, you trained me. As similar to, I think, Gayle and Jonathan, I was in a situation where I really didn’t have a reliable assistant. While I very much enjoyed learning both techniques, Dr. Challa taught me his technique as well, it was just more practical to do it this way. But you’re right, I think early postoperative leaks can be more of a problem so you need to be mindful of your closure quite a bit on this approach.
[Leon] Next slide, Minji.
[Ang] So we can actually move onto flap creation if that’s okay Dr. Herndon.
[Leon] Yes.
[Ang] There’s a couple of videos on that. The trapezoidal shape. This is your video, Dr. Herndon.
[Leon] Yeah, so all of us on the panel probably have gone through different geometries of our flaps. Start out with a rectangular 25 years ago and when to a triangular. I’ve liked the trapezoidal for the past few years, just because with this I can pretty easily close it with two sutures, most times. Now this is a larger flap that I typically use for an Ex-PRESS shunt, I think this is probably a standard trabeculectomy flap. But I found that, again, closing this with two sutures at the apex, two 10-0 nylon sutures, is a way to streamline your surgery. And I teach the fellows about being careful with their surgery, but also being very efficient with their technique.
Stuart, do you have a word about the geometry?
[Stuart] I don’t think the geometry is really of huge consideration. Whether you do a rectangular flap or trapezoidal flap. I think the main consideration is making sure that your sclerostomy itself, the edges, is far away from the flap edge as you can. If that entrance-
[Leon] Pause here, Minji.
Pause on the video. So Stuart, you do a rectangular flap, it looks like.
[Stuart] Yes.
[Leon] And how many sutures do you normally need to close?
[Stuart] I use two as well, through the corner. I like to get that nice even seating of the corner right into that bed. I tend to tie my flaps fairly tight to avoid post op hypotony. And then release the sutures as necessary.
[Ang] We’ll show the suture positions later as well.
[Leon] Any other thoughts on geometry regarding trabeculectomy surgery, guys?
[Henry] I was going to chime in. I do, exclusively, Ex-PRESS shunt. I’ve tried triangular, trapezoidal, rectangular. You need a flap that’s large enough to stabilize the expression. So I found that triangular with smaller flaps tend not to work so well. But in terms of trapezoidal, rectangular, I haven’t found a difference in my experience.
[Leon] Thank you, Henry. We have questions now, Divakar?
[Divakar] Yeah, a couple of questions are coming in and some of these I think we’ll get to. But Dr. Cohen asked, “Do you believe that past angle surgery, such as a Kahook dual blade affects trab success?” And Dr. Vanhassel also asked, “Given the current options of traditional trab, Ex-PRESS shunt, ab-interno Xen, how are you choosing?
[Leon] I’ll answer Shawn’s question first. That’s the thing about MIGS, we’re not going to get into MIGS much in this lecture. But I don’t think it precludes doing trabeculectomy surgery in the future. I haven’t seen any data, that’s really my personal experience that suggests that trabeculectomy surgery’s going to be less effective if you had a prior MIGS. Any other thoughts of the panelists?
[Gayle] No, I would say that I couldn’t say I have enough experience with trabeculectomy after MIGS to really comment. But other than the fact that most of the MIGS procedures are in the nasal portion of the angle. So as far as directly affecting the anatomy during the surgery, I would not think it would be an issue.
[Henry] I was going to say I agree with that. In fact, this is something we can go into. Typically nowadays, by the time we get the trabeculectomy, I’d tried Kahook dual blade and some of these MIGS procedures first before I even getting into this point.
[Pratap] Any conjunctival sparing procedure doesn’t seem to make much difference. I think we try to look at that with one of the fellows. Didn’t get a high enough in to really publish it. But if you have anything that affects the conjunctiva like the Xen implant, I think, that’s where there may be a difference.
[Jonathan] The one exception I might throw in, which is a rare case, and I don’t think really should influence practice patterns. But there is the occasional patient after going the otomy type procedure, that when experiencing hypotony, the eye may fill with blood. Not a common thing, in our series of some 200 and some trabectomyeses about 5% made hyphema spontaneously. But occasionally you can see that in the OR. So just.
[Leon] And regarding Sarah’s question as far as which approach do we take, Xen versus trab Ex-PRESS versus standard trab, we’re still evaluating Xen. My approach is external Xen and I’ve found good success with doing a tenonectomy.
Primarily, patients who have fairly think conjunctiva, certainly haven’t had good success or they’ve had previous conjunctival procedures. Trab Ex-PRESS versus trab, there’s some considerations we talked about earlier, if the patient’s on anticoagulation, the trab Ex-PRESS is really, in my hands, the way to go. There’s not an iridectomy that’s required and we’ll talk about iridectomy later in this program.
But Trab Ex-PRESS is still my go-to trabeculectomy. Any other thoughts on the panel?
[Gayle] I use trab Ex-PRESS also, almost exclusively. The rare situation of a phakic patient with a fairly shallow chamber would be the exception where I might actually do an iridectomy instead of the shunt.
[Pratap] I might be the youngest old person around. I still don’t use the Ex-PRESS shunt just because I just, it’s another piece of hardware in the eye, just a philosophical difference is all.
[Leon] Sure. Next slide, Ang.
[Ang] Next we can talk about mitomycin C application techniques. I believe I have three or four videos on this. The first one is Dr. Challa’s technique with the sponges.
[Pratap] I still like sponges, I like to spread them out, get them past the edge of the conjunctiva, that seems to give a nice wide bleb. It does tend to be more cystic than some of the other ones and more localized. But the other reason I like the sponge is because if you come back and do endocyclo in patients you’ve done trabs on, if you look in the area where the sponges were applied and all of you do this, with the endoprobe, you’ll see the ciliary bodies usually knocked out in that area or at least considerably affected compared to the other parts.
I think we’re having two effects here. One is an effect on the conjunctiva, but a little bit of the mitomycin is diffusing through and affecting the ciliary body underneath the decrease, some fluid production as well. But we see that. Because patients that have relatively low blebs can still have very good pressure control with trabeculectomy surgery. I do all with mitomycin.
[Leon] Harry, I think you use sponges.
[Harry] Yeah, nothing more to add than what I do, the same thing like Dr. Challa does. I guess we’re going to get to this next. I think the main difference would be whether you do the flap first or flap second. I think that probably makes a big difference.
[Pratap] We all may be going away from sponges now, because I think we’re going to start having some restrictions, right? On the way we handle mitomycin?
[Leon] Yeah, that’s a good point. There’s this thing called the USP 800, where products like mitomycin, which might be toxic to our staff, are being further evaluated. So the thought is that we should go away from sponges because of the handling process. That’s where Mitosol might have some benefit. We don’t use Mitosol, some of I think do. Gayle, you have some experience with Mitosol.
[Gayle] I do. Yeah, a couple years ago our hospital mandated a change from the compound in mitomycin over to Mitosol. And at the same time then, I changed my technique from the sponge technique where I used to a corneal shield cut in half and spread most posteriorly under the incision, over to a dilution of the Mitosol 50/50 with lidocaine with epinephrine. And I inject that at the beginning of the case inferiorly, on a 30 gauge needle fairly far away from the area I’m going to be working on and then I will massage it into the area. And I have not been able to tell any significant difference in the healing of the trabeculectomies with that Mitosol diluted approach. As well as with the injection versus the sponge.
[Leon] Anyone else on the panel use Mitosol?
Okay, Ang, who’s video is this?
[Ang] Dr. Gupta actually uses the 30 gauge needle and injects a combination of lidocaine mixed with mitomycin.
[Leon] Divakar, can you talk about your technique?
[Divakar] Yeah, I like this technique because I think it’s led to more diffuse blebs than sponge. It also allows me to adjust the concentration of mitomycin. So in some patients that I think are more prone to scar, I’ll use full strength, which for us is .4 mgs per ml, but I can dilute it in patients that I think I’d be more worried about a leak. And give a lower dose of mitomycin. I think this, I inject usually superotemporally, and try to spread the mitomycin bleb nasally and protect the limbus.
[Leon] Next video.
[Ang] And this is your technique, Dr. Herndon.
[Leon] I might have the most aggressive approach. This is mitomycin 0.4 milligrams per mL, .2 ml of it. And as you’ll see, I inject it just sub-Tenons. And I do it, to Henry’s point, I usually cut my flap first, as you’ll see. We did a randomized controlled trial a couple years ago, Michael Quist was the lead author, where we randomized 50 patients to sponge technique, this conjunctival incision technique versus 50 patients who had this injection technique. And we followed several parameters, again, this was with Ex-PRESS shunt surgery. And it’s a short term study, we followed patients out at least until six months. But we found lower pressures with this injection technique compared to the sponge. The sponge eyes required more fibraview injections. Required more BP glaucoma surgery. And we also looked at the Indiana Bleb Grading Scheme, and there were some more positive parameters associated with this technique than with the sponge.
The thought is that if you look at any study that’s used mitomycin with trabeculectomy study, most all of them have shown that if you have a wider area of diffusion of the mitomycin, then you will have better pressure control and more diffused blebs.
Now, I will tell you I use 0.3 mls of this for the study. But if you follow some of these patients out, three or four of them did have quite ischemic blebs. So my recipe now is .2 or 80 micrograms, mitomycin versus 120 micrograms is what I used for the study. Pretty aggressive approach.
[Ang] All the videos I have for mitomycin C application and also if you think this is a good time to talk about whether one prefers to do complete the flap before or after?
[Leon] Any thoughts on that, Jonathan?
[Jonathan] I typically inject mitomycin C with lidocaine like Dr. Gupta, superotemporally, at the very start of the procedure. It gives good anesthesia and makes it easier with a topical approach without any traction suture in most cases. And that’s why I do it for the anesthesia approach. There was a study from BJO a million years ago that found better pressures in people who had spongest, actually, underneath the flap. But of course, all of us worry a little bit about mitomycin C getting in the eye. On the other hand, many of us now inject mitomycin C after a Xen, or after a bleb needling.
[Leon] Good point. Any other thoughts?
[Divakar] There’s a question for you, Dr. Herndon. From Dr. Amally, “Do you irrigate out the mitomycin?”
[Leon] Yeah, yes I do. This is such a very short video clip. After applying the mitomycin for the number length of time that you want, then I do irrigate with copious balanced salt solution, just as I would with sponge, yes.
[Stuart] Just another quick note about if you use sponges, the mitomycin is actually absorbed very quickly within 45 to 60 seconds. So I will repeat my application of sponges. If I want two minutes, then I’ll do two separate applications, four minutes I’ll do four separate applications, rather than doing one sponge for four minutes or one sponge for two minutes.
[Leon] I will also bring to your attention the TB syringe that I use has a really tapered tip. If you use one of these Luer lock TB syringes, they’re really fat and they can tear the conjunctiva. So for our technique it’s important to use this really tapered tip.
[Gayle] I would just make one comment on the sponges because again, up until a couple of years ago I did use sponges. I had switched over to using that cornea shield because I felt that it was less friable. And very easy to identify that fact that there were only two halves that I was using. I have had an occasional call from another frantic surgeon worried about leaving a piece behind or having a small piece that they thought may have been under the conjunctiva. And that concerned me enough to try to find a material that wouldn’t do that.
[Leon] Do any of the panelists have any experience with Ologen? I tried years ago. But this really is a fairly thick material, it can cover the, I do suture lysis. So it can cover your sutures. And I had not gone back to using it.
[Ang] Still me, Dr. Herndon.
[Leon] Ang, I’m sorry.
[Ang] We can move on sclerotomy creation and there are a few videos on this. We can talk about the use of the supersharp, Kelly punch, and Ex-PRESS shunt.
This first one is Dr. Challa’s technique in using the supersharp.
[Pratap] I like to use a supersharp to demarcate exactly how wide my opening will be. And usually I go about a millimeter and a half on each side. If there’s a little bit of cautery that makes it such that there’s going to be a little bit of asymmetrical flow, I may shift it over slightly to the side that won’t have quite as much flow from cautery at the edges of the scleral flap. And you can see here, once, just punch it out and you get a nice opening at that point.
[Leon] Does anyone cut their flap? I think you, Pratap, being the basic scientist would want to keep that flap and study it.
[Pratap] So we did, several years ago, we took them and we accumulated them and we did some gene expression analysis of it and published it. Maybe a little bit what prompted me to do this technique. I used to really use it, used to outline it and then just cut it out with a Van Ness scissor, actually, get a nice little block. But now just punching it is just as fast, so just punch it out.
[Ang] The next video is yours, Dr. Herndon, your technique.
[Leon] So I do something similar. I use a Kelly punch on my standard trabs, I make a little larger incision, I go in with a super blade, about .5 millimeters from the edge of the wound, I often then go all the way to .5 from the other end. And I like to get a good 3 punch sclerostomy. And one thing that, when I teach trainees, many times when trainees start doing this, they’re a little nervous about it. And are a little afraid to get a full-thickness bite. It’s amazing, the first few trabs they do, they get these partial bites. You really got to clamp down on it on that lip to get the full-thickness sclerostomy, so don’t be uncomfortable with really placing the Kelly punch and turn a bit perpendicular in getting a good bite for the sclerostomy.
Any other comment?
[Stuart] Real quickly on I think it’s important to come in with your supersharp blade perpendicular to the globe. That way you don’t get this lip if you come in more parallel to the surface of the globe, which I think is what the beginner’s problems are. That way you can get the Kelly punch over the lip rather than fighting to get it forward over that very thin beveled lip.
[Leon] Right.
[Gayle] Leon, I was just going to mention that prior to your actual entry, whatever technique you’re using, to definitely be sure that you have created your paracentesis and have good access to the anterior chamber. Because those are the situations where you want to be able to add fluid to the anterior chamber immediately to help you at certain situations and trying to do it afterwards is much more difficult.
[Leon] Yeah, that’s a great point. Clearly make your anterior chamber access prior to making your sclerostomy.
[Ang] And this is your Ex-PRESS technique, Dr. Herndon.
[Leon] Yeah, so Ex-PRESS, I use a use a 25 gauge needle to make a sclerostomy. I like to turn to Ex-PRESS 90 degrees and then just sort of tunnel it in, screw it in place. And once you pop through, you rotate that Ex-PRESS back. You always want to make sure that, let’s pause it there. You always want to make sure that. And one thing this illustrates very nicely, if you’re going to do Ex-PRESS shunt surgery, I like to and I would recommend using a smaller flap. Let it run a little bit.
[Pratap] In general, with all trabeculectomies if you make a thinner flap, the sclera tends to sort of disintegrate over time with flow. So the thinner flap you make, you can actually end up with a little bit better flow.
[Leon] So stop there. That’s good. The point is, these Ex-PRESS shunts only come in one flavor now, P50. 50 micron lumin, have a posterior slit. And if I’m doing Ex-PRESS shunt surgery, my thought is you want to help to facilitate posterior filtration. So if you have a huge flap, then aqueous needs to traverse a greater surface area to get subconjunctival. I like to have the back end of Ex-PRESS shunt near the back end of the trabeculectomy flap.
[Divakar] Dr. Herndon, there’s a comment by Dr. Leonard Rappaport about difficulties recovering bleb function after Ex-PRESS shunt, do you have any thoughts on recovering failing blebs that have an Ex-PRESS shunt?
[Leon] Hey, Len. I’m not a big needler, unless there’s an encapsulated bleb. One thing that is different with an Ex-PRESS shunt, you can’t be as aggressive as you might be with a standard trab, I know some of my colleagues will go inside and they’ll do external needling, actually go into the anterior chamber through the sclerostomy. Well, you can’t do that with Ex-PRESS shunt. Nor can you do an ab-interno revision with a spatula with Ex-PRESS shunt. So you do have some limitations in your postoperative options with Ex-PRESS versus a standard trabeculectomy.
[Gayle] So Leon, I’ll just add that that I also do again, mostly Ex-PRESS shunts and I use a sapphire blade, which I believe is now currently available from MST. That’s a more trapezoidal shape at the tip and actually I find that it makes a very nice shape for exactly the insertion you’re speaking of when you’re turned 90 degrees. And then once in your turn it so that the flange is now upright. And then I have found that when I have done an actual bleb revision of my own, patients with an Ex-PRESS shunt, that the area of fibrosis and scarring that is limiting the flow is the same as if it were a trabeculectomy flap with a punch. Which is that it’s along the ridges or along the grooves and it’s an episcleral type fibrosis or membrane that has formed. The Ex-PRESS shunt usually still has significant flow coming through it.
[Leon] One thing I also would emphasize, when you place the Ex-PRESS shunt through the sclera the needle sclerotomy, you want to make sure that the Ex-PRESS is flush with the scleral bed. If it’s tilted at any, if you don’t feel comfortable about it, if it’s in the cornea, as I’ve seen, you’ve got to take it out and convert to a standard trab.
[Joanne] I had a quick question for Leon or Gayle, who do a lot of these. And I think you’ve may have already somewhat addressed this. But when you’re entering with that 25 gauge needle, are you thinking more of like a tube placement, where you want it pretty close to the iris? When I’ve worked with trainees, sometimes, like you said, they end up in the cornea and you’re assuming really that’s not endothelium friendly. If you could address a little bit what you’re thinking when you’re putting in your sapphire blade or the 25 gauge.
[Leon] Ex-PRESS shunts typically don’t work very well if they’re in the cornea. So I do tend to have trainees make sure they’re doing perpendicular or more parallel with the iris. More parallel is going to be the approach you want, you surely don’t want to have it too anterior. But yes, that’s a good point.
[Gayle] Right, I agree. I would try to aim for either midchamber or closer to the iris surface. Given that you have a lumen on the end as well as on the anterior surface of the Ex-PRESS shunt, you can have it fairly close to the iris surface and you’ll have no issues if you have some occlusion towards the tip of it. Because you’ll have the anterior area that’s also open.
[Leon] Okay, Ang?
[Ang] Next we can talk about iridectomy. There’s only one video for this. And this is your video, Dr. Herndon.
[Leon] Yeah, so iridectomy I do standard when I do standard trabeculectomy surgery. I know some on the call do not utilize an iridectomy. It’s important to be full-thickness. Now this is a point of the procedure where you can get a little interesting with bleeding, especially too far posterior. But I’ve used it forever with all my standard procedures. I use a .12, bring out a little peak of the iris, Van Ness scissors to make a nice cut. Jonathan, I think you mentioned you don’t do an iridectomy in all your trabs?
[Jonathan] It’s a wise thing to do an iridectomy. Let me not say anything else. That being said, for people who have deep chambers or are pseudophakic, I typically don’t do an iridectomy. Dr. Debarros put together a series of Dr. Spaith and my patients, was published in Eye in 2009. And we really found that the outcomes were the same. But there was less inflammation in the first month without an iridectomy. Every so often if you haven’t done the phaco, you get a surprise where vitreous comes forward when you do the iridectomy. It’s a source of bleeding. But if you don’t do an iridectomy, it’s really pretty critical to control the anterior chamber. And so if you’re planning high flow, the chamber’s at all shallow, that’s a case where an iridectomy is just plain smart. But in a pseudophakic patient where you’re planning to leave things fairly tight and you’re confident that you can control the chamber, it’s an option not to do it.
[Pratap] And issues with patients on Flomax? Their irises are more floppy?
[Jonathan] No, I can’t say consistently that I’ve seen that. I will say that, again, for patients on blood thinners as you were talking about earlier, it’s lovely not to do an iridectomy.
[Leon] Okay, Ang?
[Ang] We’ll move on to the flap closure. There are a couple of videos here. The first one is Dr. Herndon.
[Leon] Again this is my trapezoidal flap technique. I use a 10-0 nylon suture. It’s important to have as far posterior pass as you can. That makes it a lot easier for laser suture lysis. I employ laser suture lysis procedures on my sutures. I don’t do releasables, Stuart has a video of that. But for if you’re going to be doing laser suture lysis, it’s important to have a very long 10-0 nylon suture. And I also test the wound. I want to make sure that the anterior chamber is maintained, and I’ll do, I’m not sure if I can show it here. But I do a Carlo Traverso maneuver. I think is probably the most important step of the procedure, once you’ve rotated the sutures. Then we’ll apply pressure to either side of that flap. And based on the side that has the greater flow, that’s the side that I’ll make a little note in my op note that I want to cut the suture first with laser suture lysis.
[Ang] Sorry, I thought I had a CT on video, I guess I don’t.
[Divakar] While you’re setting that up, there’s a couple questions about the iridectomy. Do any of the panelists use Miostat? And did patients with more inflammation post iridectomy have different outcomes in trab’s success or longevity than those without?
[Jonathan] The answer was no. So the two groups were equivalent in terms of outcomes. So although we saw less inflammation in the charts, and this was a retrospective review, it didn’t seem to make a difference. Both groups did okay overall.
[Divakar] And I tend not to use Miostat during trabeculectomy mostly because I do want the chamber to be deep. And so I antroponize patients at the end of the procedure, even if I do or do not do an iridectomy.
[Henry] I guess the question also reaches back to whether you do a cataract surgery combined with trab or not. So obviously if you’re doing a cataract surgery you’ll need to get that pupil down. But otherwise, in general, you don’t need Miostat if you’re just doing trabeculectomy by itself.
[Pratap] Henry brings up a good point. If you don’t use it post cataract, you’ll end up with a much larger iridectomy than you anticipated.
[Henry] And blue eyed patients will be very upset afterwards. (laughs)
[Ang] And this is Dr. Challa’s video which is a similar releasable technique. You will see it’s more meticulous in terms of checking for the tightness of the suture before actually tying down the slipknot.
[Pratap] I like to check flow, so I’ll inject the BSS in the anterior chamber several times to make sure I have good flow of the flap edges. You want it just to well up and fill up the flap edge over about one to two seconds. You don’t want a gush of fluid where it’s coming continuously out where it will over filter. Is that what we’re talking about here?
[Leon] Yes.
[Pratap] Okay, good.
[Joanne] I’m curious for the other panelists too, is anybody using an AC maintainer? I don’t routinely use one, but it’s something that’s always been in the back of my mind that I feel would maybe make me feel a little bit more comfortable with I’m trying to rapidly close down this flap.
[Leon] I don’t use the anterior chamber maintainer, there was a question also on preplaced sutures, which is another step one might take to make one of them more comfortable. But I don’t utilize either of those techniques. Anybody else?
[Divakar] No.
[Gayle] No, sorry, I don’t tend to use anything to maintain the chamber if it’s a fairly standard case. But I will say if there’s a case where I am expecting that large drop in pressure, then I might stabilize the anterior chamber with a viscoelastic. But only a small amount. I really don’t want to distort the architecture near the area where I’m either going to place the Ex-PRESS shunt or do a PI.
[Divakar] I agree with Dr. Howard. In rare cases I do use viscoelastic. And I used to use it a lot more but then I also found it difficult to judge the flow through the trabeculectomy when I was getting to that step. So I’ve tried to do that less.
[Henry] I often do preplaced sutures. And mainly because when I’m working with trainees, it’s actually easier to suture while the eye’s pressurized. Even before going into the eye. Once the eye’s softer and they’re pushing on the sclera as they’re suturing, it becomes harder and also messier. And so often preplaced suture will be pretty easy to do.
[Leon] Next, Ang?
[Ang] This is the release of a suture of Dr. McKinnon.
[Leon] Stuart?
[Stuart] Yes, you’re taking a corneal bite here first.
[Leon] What suture are you using?
[Stuart] This is a 10-0 nylon. And then you’re going to pass, well, the other side I guess. So now you’re going to pass very thinly under the limbus, under the vascular limbus, super thin, paper thin, and come out down the flap. I have not actually entered the anterior chamber at this point. So it’s very important to make sure that pass is very thin. If it’s too deep then you might pass through the point where you need to do your blade. So you basically have preplaced sutures at that point. And then you can do your sclerostomy. Then you’re passing through the corner of the flap, and into the corner as well, a fairly long pass, as Leon mentioned. And you leave a loop. And then you’re going to tie four throws and pull the loop down in the same direction as the corner.
I really like to tighten it in there so everything’s just super, super tight. And at the end of the case you’ll end up trimming the corneal edges so that they retract a little bit and not poke out of the cornea. The advantage of the releasable is you can put it out at the slit lamp and occasionally if they get scarred down you can always go to laser to do a laser suture lysis.
[Leon] What about the risk, Stuart, of infection with the corneal sutures?
[Stuart] I haven’t seen it. Because they come out within the first month, typically. That’s your window after four weeks, typically. The pulling it out isn’t going to affect the flap architecture at all.
[Leon] Again, a note to the attendees. We will share this lecture with you, I know you want to look through this technique several times. We’ll be passing this on to you after the call.
[Stuart] It’s a modified technique of Al Coker, who actually does it in the reverse direction, but I do it from the anterior direction so that I can put these sutures in while the mitomycin sponges are sitting there. So I’m more efficient in the OR.
[Leon] Okay, any other comments?
[Jonathan] I think it’s a great technique. I use this releasable in people with really thick Tenons or conj, sometimes when I’m afraid to suture lysis or laser won’t be possible. I used to do it on every case. I’ve had one infection in 20-some years that was a corneal infection where the suture had come loose. But I left all of mine in when I didn’t need to release them. And so there are lots and lots of people with these things left in for many, many years. But I did have one.
[Leon] So let me clarify this, Jonathan. You’ve had just one infection in your 20 years of practice?
[Jonathan] One infection at the external releasable suture.
[Leon] Okay.
[Jonathan] Yeah. (laughs)
[Leon] Well, I did teach you well, I guess.
[Ang] We can talk about conjunctival closures next. There are a few videos on this.
[Minjy] The first video that we’re going to show addresses the question of whether or not people do tenonectomy, or what to do with the Tenons. So Dr. Herndon, the first video is your video.
[Leon] I do the standard on my external Xen. But I typically don’t use it in my trabs, unless it’s really thick and anterior. I found that Tenons can block your visualization for suture lysis. So you want to make sure that you’re cutting and spreading on the Tenon side, not too high on the conjunctiva otherwise you can cut the conjunctiva. And then that’s, you have to be creative in finding ways to close that. But yeah, it’s fairly simple to do that. You just have an assistant. Again, you need an assistant to do this. Grab a .12 and pull the Tenons forward and just light that section with Van Ness and then Wescott scissors and excise as much as you can.
Maybe someone on the call can comment on the success rate of trabeculectomy surgery with or without tenonectomy. I haven’t seen studies that addressed that.
[Joanne] I was actually curious about this and I looked in the literature. Actually, there was a paper that we published out of Duke with Bruce Shields. But it was a limbus based study where they compared partial to total tenonectomy and didn’t find a significant difference in the outcomes. I’m like you, I don’t routinely do this, but if I have a patient who has a lot of Tenons and I’m worried about visualizing the sutures for suture lysis, then I might try to excise some of it so I have better visualization. But typically I don’t do it routinely.
[Leon] You sure this is my case? Look at that big conjunctival incision. (laughs) It’s rare that I do a big iritomy like that, but that’s interesting.
[Gayle] Leon, I would comment that I switched, probably at least 10 years ago now, to the Blumenthal lens for my laser suture lysis. And with that pinpoint area, I have been able to find all my sutures. So I have not felt the need to remove Tenons in order to have better visualization. So that’s been a game changer, I would say for me, with laser suture lysis.
[Leon] Right, I use a Rich lens and the key is, as I teach trainees, you’ve got to really spend a lot of time blanching the tissues. Just give it time, eventually that suture will come into view where you can laser it.
[Minjy] All right, and in the next video, moving on to just closing the conj. Dr. Herndon this is your technique.
[Leon] So it’s great to have fellows because Thomas Hunter taught me this technique when he was our fellow years ago. Each of us on the call has gone through different closure techniques, I do two wings, use a 9-0 Vicryl on a CS needle. I’ll pull it together on one side, I determine which side I close first based on the mobility of the tissues. And let’s actually go back, Minjy, if you can rewind that just a little bit.
And it’s important to do, here we go, stop. Stop there. It’s important to do a circumferential pass. In Mike Quist’s paper we looked at radial passes and that had more effect on astigmatism than circumferential. So I take a big circumferential bite at the cornea, go ahead and forward it. And we’ll bring the conjunctiva forward, take a really big bite. My trainees hear me talk about big bites all the time. Big bites, big bites.
So do a 3-1-1. And then I like to give Kenalog, posteriorly as far back as you can. And then I run this dog ear close with usually two passes, I don’t lock these. And I keep a tail on the other end where I will suture to. So I’ll do a 3-1-1, going back to the tail that was already there and close that. You can probably get by with just this, but then I really to give a little more security, I will place another wing again, keeping circumferential in the pass through the conjunctiva is trapezoidal as well. It kind of cinches up the wound at the limbus. And with this technique, my leak rate is very low. And so I’ll keep this until I’ll have more leaks and then I’ll change to something else.
[Divakar] Just a couple questions on what suture you use, Dr. Herndon, and whether you have a preference between monofilament or braided, and if you’ve noticed more bleb leaks with tenonectomy or not?
[Leon] In this case I used either a CS cutting needle or BV if the conjunctiva was really thin, probably 10% of my cases I’ll use a BV needle which is much flimsier, hard to pass through the cornea. But in this particular video I used a 9-0 CS Vicryl needle. And with a tenonectomy, as long as you don’t puncture the conjunctiva, the leak rate is not any increased.
[Minjy] Okay, so then the next video is a video of Dr. McKinnon’s closure which is pretty similar. But he uses the traction suture as part of his closure.
[Stuart] My traction suture is placed right as the vascular conj border. So it will reapproximate to the same position. I also bring my needle on the wing suture up through conj underneath first, so that the knot tends to be a little more buried. Then I run the dog ear just like Leon mentioned. And now I’m converting the traction suture to just a horizontal mattress suture. So it really spans quite a bit of the incision and really tightens it down. I have had virtually no wound leaks anteriorly with this technique.
It’s important to make sure that you place that suture at a point where that limbus is all the way across tight.
[Leon] Stuart, it looks like you leave a little conj flap at the anteriorly?
[Stuart] It sort of depends how much conj you take and exactly where your sutures are. But that all tends to retract over time.
[Leon] And tell us what suture that is, what Vicryl?
[Stuart] That’s an 8-0 Vicryl on a TG needle because episcleral bite, I think, is important so that you have a good footing for that suture because it’s at a lot of tension. And I haven’t seen conj ripping really. This is also 8-0 on a TG for the mattress. It’s a good solid technique. You get three points of fixation plus the mattress suture is holding down the portion of the conj that’s directly over the flap.
[Joanne] There was a question about braided versus monofilament. I know I think among us we kind of vary. I personally do a braided because it’s probably a little more comfortable for my patients, I think. But I’d be curious to hear my colleagues who do monofilament, what the pros and cons are. I remember as a fellow we had a series where the monofilament dissolved too quickly, which might be helpful in some circumstances but in other cases it led to early wound leak. Thoughts?
[Gayle] I have a similar closure to Dr. McKinnon and I use the 8-0 braided Vicryl as well. And I make probably one or two more episcleral bites on that radial side as well. Generally trying to divert some of the flow more posteriorly so that you don’t get this circumferential fluid that may go down and block the puncta, create all kinds of hyphema problems. And then also I will most of the time, put a 10-0 nylon wide horizontal mattress suture at the anterior edge so part of the end of the cornea and the other part over the anterior edge of the bleb. Also pushing it posteriorly and it’s kind of a belt and suspenders approach so that if the Vicryl dissolves a bit too early then the nylon is there holding it.
[Minjy] Okay so the next video is a Condon closure. And this video is from Dr. Amir, who is on the call but not here as a panelist.
[Leon] Yeah, I’ve employed this technique in the past as well. One thing that Kelly is doing is she’s leaving a lip of conjunctiva anterior. Looks like about 2 millimeters of conjunctiva. This is a nice tight closure. Modified Condon closure. And I think she uses a 9-0 Vicryl in this case.
[Minjy] I think this was an 8-0 on a BV.
[Leon] Okay, but you’ve got to have, obviously, meticulous passes and it just takes a little bit longer than a wing technique. But we’ll have this loaded up for everyone who wants to spend some time trying to perfect this technique.
Any other thoughts on the Condon?
[Divakar] My only concern with the Condon closure is just the number of passes through the conjunctiva. I have adapted your technique, Dr. Herndon, just because it puts all the tension away from the flap and most of your passes through the conjunctiva are away from the scleral flap.
[Leon] I think Garry Condon got this from Wise, he modified this from originally a Wise technique. But yeah, it really gives you a nice water-tight seal. And that’s what we’re all interested in. There’s nothing I hate more than a bleb leak. Because when you have a bleb leak, the conjunctiva is scarring and you want to have that belb elevated. If you have a conjunctiva in touch with episclera, then you’re going to have episcleral fibrosis, and your bleb is going to die. Not to mention the risk of infection. Did I mention that I hate bleb leaks?
Yeah, that’s a nice closure.
[Jonathan] I do want to say this is a meticulous closure and a great demonstration by Dr. Amir. The thing we’re not saying is it’s an elegant closure but it’s not only the quickest closure and there’s some effort and work involved. And this is very well done. But I think that’s part of the reason it’s not 100% popular.
[Leon] Yeah.
[Minjy] This should be the final pass and it’ll be going through episclera, so that when you’re tightening everything down it’s taking the tension off of the conjunctiva. And the next video that we have is this is Dr. Challa’s video closing the posterior incision.
[Pratap] This is just as standard closure, couple of interruptus, depending on how wide the wound is. And then just a running at the end. The one thing to keep in mind is that all wounds when they heal they bring in fiberblast, when they bring in fiberblast they contract. So if you have a wound anterior or posterior, the main thing is try to control the contraction of the wound here. You can’t see it here, but take little passes through the posterior pass of this you grab a little bit of the posterior Tenons and that way you’re incorporating that into the closure and it keeps that wound pulled back away from the flap.
One thing I will mention, anteriorly, if you’ve taken the conj down right at the limbus and Leon showed this nicely, is you drape the conj further over the limbus than where the natural position of the wound opening is. And the reason for that is the wound is going to contract. And when it contracts you don’t want it to contract back beyond the limbus.
And then here it’s just a standard running closure here. You can either lock them or non locking. I usually do non locking just because it doesn’t make any difference really in the outcome. But the one key here is you always pull towards the limbus as I put there in the video. The reason for that is that the weakest part of the underlying strength of the conj is at the limbus. Because we’ve disinserted Tenons there. So if you pull posteriorly you will cheese wire the conj, so you always want to pull anterior when you’re putting tension on the wound.
[Minji] And then the final video is a video of Dr. Herndon’s last check before the end of the surgery, once everything is closed. Doing a CTM to check for leakage.
[Leon] Yeah, this is very important as well. This is a Carlo Traverso maneuver. I tell my patients, we all rub our eyes when we wake up in the morning. So this is an early morning eye rub test. I’m pretty firm, I’m pretty aggressive with pushing down on the flap. You want to raise the flap and really spend a lot of time at the limbus making sure there’s no leak. You can run that again. Again, just use a cotton tip, and just apply a Carlo Traverso maneuver and really get the bleb elevated nicely, want to make sure the chamber remains deep, and that there’s no leak.
You can tell your patients all you want to, we all rub our eyes without thinking about it.
[Minjy] So then moving on to the final section of our talk is talking about postoperative management once the surgery is done and some things to consider. The first slide is what people do considering what they do in terms of steroids. So we saw a video earlier where Dr. Herndon injects Kenalog posteriorly. And then postoperatively what do people like to use in terms of drops or a newer optio?. And we have a video of here is the Dextenza implant that goes into one of the puncta and releases dexamethasone over 30 days as long as it stays in place.
[Leon] Yeah, so this a new addition to our momentarium. Primarily it’s done to control inflammation and pain at the cataract surgery. But there are larging indications, as I would use this with phaco and phaco MIGS. But here lately, I’ve been utilizing this with tubes and trabs. To me, the point is that some patients don’t remember to take their Prednisolone four times a day or six times a day. And it’s nice at least through that first few weeks to have that dexamethasone on board. I can’t tell a difference right now, on the bleb morphology, but this is a nice addition to these patients who qualify for having a Dextenza implant. And actually Pratap, you turned me onto this.
[Pratap] And I think the way to look at it is equivalent to QID steroids tapering off over about three or so weeks or so. With trabs, I still supplement it with topical steroids. With tubes, depends if they start getting a little big inflammation I’ll add topical steroids on top of that. But if they don’t, I won’t just leave this in. But with trabs I definitely still supplement with topical steroids. Phacos also, I usually don’t use steroids. Most of the patients don’t seem to, although I’ve had a couple that have broken through and have some later onset inflammation which I’ve had to come back and put steroids on.
[Leon] Any other thoughts from the panelists? With their postoperative regime?
[Gayle] So I start my trabeculectomy patients on medications within three to four hours after surgery. I don’t patch them closed, I just use a shield and ointment. So they start using every two hour, Prednisolone, generally on the first day. And then when I see them on day one in the clinic, I rarely would make a change to that unless I felt like their conjunctiva was quite thin or fragile during the case. And then I might back off already to four times a day. And then I’m tapering slowly, usually over three months or so. I don’t often extend it out, but I have some colleagues I know that use at least very low level steroid for six months.
[Leon] Jonathan?
[Jonathan] I’m a believer in steroids, as everyone has said early on. I dose steroids for six times a day for the first week at least for most of my patients. I think not using steroids, there’s definitely a higher rate of failure. I mean us not using them, I mean the patient’s choosing not to use it. I don’t patch my patients and the sooner they start the drops the better. But usually about four to five weeks is how long most of my patients are on steroids. Unless there’s inflammation or.
[Divakar] For the panelists that use steroid implants, have you noticed a difference with block patients?
[Lean] No, I haven’t. We, the past four to five months, And I can’t tell a difference in my phacos, my phaco MIGS, my trabs or tubes where I’ve used it. I think it’s been effective in all patients.
[Pratap] I agree, same here. I haven’t seen any difference. Like I said, the one thing to think about if you’re going to use one these implants is it’s about to QID probably for about three weeks. So then you adjust the rest of your medications around that. And I agree that more steroids are better in a trab and I think most of us who don’t block anymore for our procedures, we don’t patch the eye so then the patients, I’ll have them start medication right away right after surgery. If you block the eye, you can patch it, then you’ll have to wait and start the next day when you take the patch off. So all the patients get shields basically.
[Leon] One thing I would say in this age of COVID, we really want to try to limit the number of drops our patients take. Post operatively, even glaucoma drops, if we can find some ways for sustained release deliverables for them. Obviously, trabeculectomy requires a lot a follow up. And so in this age of COVID, that sounds sort of counterintuitive perhaps. But if we can find some way to limit their eye drop exposure necessity because many times they have caretakers who are putting their drops in, touching their eyelids. You’ve seen the video from Alan Robin with how patients don’t do as well as we think they do with putting drops in their eyes. If we can find ways to limit their topical drop burden that’d be real beneficial.
[Pratap] For trabs, I still give a lot of patients post op, just after surgery injections of subconj dex. But that varies from person to person.
[Minjy] Okay and so the next thing to consider when dealing with post op management are the flap sutures. We talked about either doing laser suture lysis, or if you’re using a releasable technique, doing releasable sutures. And the main questions there are when do you do this and how do you do it? I know at Duke our Attendings often tell us to remember to treat the bleb and not the pressure. So looking at bleb morphology to guide these decisions. And also trying digital pressure first to see their response as well.
[Leon] Anybody’s thought on that, Henry?
[Henry] Sure, yeah, let me chime in. I typically do this somewhere between two to four weeks. Rarely the first week unless you really, really have to. Especially if the bleb’s not rising and the sutures are just too tight. Typically I find that in the past month, like four weeks, laser suture lysis doesn’t help as much anymore. So if you want to try to rescue the bleb through laser suture lysis, you’ve got to do it soon. Sometimes we have to be very aggressive. We might have to cut one, or two, or three pretty quickly to get that bleb to function. The key is you want to maintain flow through the bleb. The moment the bleb’s flat, there’s no flow, it’s just going to scar down.
[Leon] Yeah, I agree. I know the take home point is you don’t want to do suture lysis post op day one, but if you’ve got a flat bleb that doesn’t elevate with digital pressure or Carlo Traverso, you’re going to lose that bleb if you don’t. Occasionally I will do a suture lysis post op day one.
[Gayle] I will say that if I have done a laser suture lysis and at that moment with a little digital pressure have not been very impressed with the amount of the pressure drop, it does take a certain amount of restraint to not go ahead and cut another stitch right then. And I will literally have the patient back one day later. Because it’s amazing over a few hours, or overnight, how things might change and then you might not want to have been doing another laser suture lysis on that patient.
[Jonathan] Great advice, some of my biggest regrets have been that second cut right then and there.
(panelists laughing)
[Henry] I guess a good question for the panelists would be which sutures would you cut?
[Gayle] So I still draw a diagram on my notes when I come back to the office of where my stitches are and which ones I would cut first. And when I make a note in the chart I describe exactly which stitch I’m cutting and which one would be the next one. Hopefully it’s a matter or two or three and no more than that. So it’s worth taking those extra notes.
[Leon] Yeah, I’m the same way. When I do the Carlo Traverso maneuver on the table, I decide which side has a better flow and that’s the suture that I typically will cut first.
[Divakar] There’s a question. If you do get hypotony after laser suture lysis, what do you?
[Gayle] Well, it’s a similar response or treatment to hypotony under other conditions. You’re going to make sure that your chamber is maintained and you may need to use cycloplegics to deepen your chamber. And then you’ll usually modify your Prednisolone or your steroid of choice regime to allow a little bit of healing. And if they’re using medications in their other eye, which might be suppressing aqueous, even in the surgical eye I might change that temporarily. Same reactions that I would have for a hypotony under other circumstances.
[Jonathan] The nice thing about that scenario is that if you have to go back, it’s easy to know what you have to do. And the transconj suture technique has really made that a lot easier. Where you just put the suture through the conj, through the flap and tighten it up. That often makes these revisions simpler. Although, hopefully in most cases just waiting it out with the other measures as Dr. Howard said, saves you.
[Minji] Okay, and then the next topic is how people use antimetabolites during the postoperative period. I know at Duke we only have 5-FU in the clinic. And again the questions are when to do this and how to do this? Typically we tend to inject inferiorly because like Dr. Challa says, it’ll get to the bleb anyway. So I was wondering if people had other thoughts or comments?
[Leon] When I do 5-FU, I inject it right adjacent to the bleb. I know the idea is it goes through the tear film and eventually will get up there. But why not put it there right away? Same thing with Kenalog, I used to give Kenalog at the end of the case inferiorly, but I got a lot of patients and their family members asking what’s the white thing in the bottom of my eye. And so I like to place that adjacent to the bleb as well.
[Pratap] The point is, no matter where you put the 5-FU it’ll get there. So that’s okay. The mitomycin’s a different issue. I usually use mitomycin, I don’t use mitomycin in the early post op period. I use it sometimes when I do repeat bleb needling, otherwise I’ve needled the bleb, didn’t seem to respond very well and then I come back and needle it again within a short period of time, within about six months. Then I’ll consider using mitomycin at that time. I use a dilute mitomycin one to three over the .4 milligrams per ml that we have. I give it about eight to 10 millimeters away from the bleb, give it about 15 to 20 minutes and then when you needle, needle from that area into the bleb. And that’s the one time I don’t go into the anterior chambers when I’m doing mitomycin needling. Mostly needle the wall of the bleb in the capsule.
[Henry] One issue that’s not on the slide is how often would you do injection? Would you have the patient come back every couple days, once a week? And I’m just going to start. Early on I would bring them back every few days. But then they would really hate it because of really severe dry eyes and cornea issues. So I learned to just monitor how the cornea’s doing. And usually it works out to be about roughly once a week. The patients typically tolerate that, once a week. But I’m curious what other people do and what they’re experiences are.
[Pratap] I think mostly it depends on how the vascularity of the bleb looks. Most of the patients I end up actually not giving 5-FU, but occasionally give patients where they have a fair amount of vascularity. And either they’re not taking their drugs, their steroids, as you prescribed or the steroids just aren’t sufficient. And then I’ll give 5-FU if I start seeing the vascularity of the bleb pick up. Particularly for me it’s around that suture line that’s in the back because that’s where all the really thick part of the capsule starts to form back there.
[Gayle] I would just comment, Henry, that if you see pretty significant epitheliopathy develop in one eye, and you’re going to eventually do trabeculectomy in the other eye, I keep notes that tell me not to do 5-FU again. Because the cornea tends to behave exactly the same in the second eye.
[Divakar] There’s a comment about Avastin, and Dr. Mundorf was commenting that Avastin placed by retinal specialists lets the retina colleague enter the posterior temporal aspect of the bleb and use the edge of the needle to lift the flap and it’s okay if he gets in the AC. Is anyone using Avastin?
[Jonathan] I’ve not tried that but I’d like to applaud Dr. Mundorf for transferring post operative management of failing blebs to the retina group. Genius, genius, Dr. Mundorf.
(panelists chuckling)
[Pratap] When the antimetabolites first came out, there were quite a number of people that had done it. And quite a number of Argo abstracts and a couple publications. And by in large, they work as long as you’re giving the injections. But once the injections stop, it seems to, the bleb success rate seems to come back and parallel that as if you hadn’t given it. In general, I don’t use it.
[Divakar] Dr. Challa, there is a question. What sequence do you follow with needling and using subconj mitomycin, is the mitomycin first or the needling or the other way around?
[Pratap] First I give the mitomycin like I said, about eight to 10 millimeters away from the bleb capsule. And then, like I said, we use a .4 milligrams per ml diluted one to three. And then give about .1CC subconjunctivally, let it sit there. Usually I try to let it sit there for at least 15 minutes, so usually let it sit there for a while. A little bit longer’s fine, but then I’ll needle it at that point. So usually about on average probably about 20 minutes after giving them the mitomycin.
[Minjy] And then our last slide is along the same vein about bleb revisions. And I think we also might go into more depth about this in a different Duke surgery session where we talk about complications with trabeculectomies. Wondering if people had any thoughts in terms of when to do bleb revisions and whether you do it at the slit lamp, or take them back to the OR?
[Leon] I’ll just say that I was not a big believer in bleb revisions until several years ago. Roy Whitacker, colleague in Greensboro, asked me why don’t you just revise the blebs? Oh, okay. So if the bleb is elevated, and encapsulated I found really success with that. If the bleb was flat and scarred, I move onto the next procedure. But I do these in the OR. I go to the theater. And typically I do an open revision, or we’ll call an excision of pull down technique. We published our results years ago when Jonathan and Chuck were our fellows. And so, those results are really pretty good. There’s an ab-interno revision that we’re starting to utilize now for patients who have had Ex-PRESS shunt. But my approach is always to do these in the OR.
[Pratap] Two different things. Go ahead, Stuart.
[Stuart] I agree with you, Leon. I always go to the OR with these blood needlings so that you really have good control of what you’re doing. I don’t use a needle, I use an MVR blade to actually do the lysis. Needle is not designed for cutting for one thing. But the tip of that blade is very sharp so you want control. If you start to get flow right away after you’ve done all the conj scar excision, then you’re pretty much okay. But if you don’t get flow, after your dissection, then I’ll go in, try and find the edge of the flap, and try and lift the flap, or enter the anterior chamber to the point where I start to see the conj come up. At that point then I’ll just inject some mitomycin on a 30 gauge needle and close it with a single Vicryl.
[Pratap] I do all my needlings at the slit lamp. I do a lot of things in the slit lamp. To me it’s just quicker, it’s faster, I use a 27 gauge needle with preservative-free lidocaine. Enter about eight to 10 millimeters away from the bleb, balloon the conj up so that you don’t puncture the conj on your way towards the bleb. And then I try to puncture the capsule in several points and then use a horizontal motion to try and connect that opening there. And then I like to go under the flap and into the AC and then really try to put the flap up a little bit and go through my sclerostomy into the AC. And then see the needle tip in the AC and then come back out again. Usually, I’ll use 5-FU in almost all those patients as well. But the key is, when you go to needle it, you have to think about, is it going to function long-term or not? If the bleb is scarred down, it’s probably only a temporary measure that’s going to work for a short period of time. The bleb has to be at least somewhat elevated to give it a chance for its survival. If the conj is really injected, sometimes I’ll use post op steroids in those patients as well.
Now, true bleb revision that I do, sometimes I do those. But those I do in the OR because I do like to go ab-interno and come out underneath the flap, under the conj, and then go the other direction as well, to come from both directions. But that, of course, you have to do in the operating room. My vast majority, I’d say 95%, I initially try needling in first at the slit lamp.
[Gayle] As a person that uses the Ex-PRESS shunt, I know Dr. Crandall has made a comment about using a cannula from Alcon, that’s used for viscocanalostomy to open internally, the Ex-PRESS. I’ve also had success in the clinic with using a YAG laser to actually laser the opening and almost ping up the device to remove whatever membrane might be in there. That has worked on several occasions to avoid even having to go to the OR.
If I’m doing a real bleb revision, I do go to the OR for that. And I think Jonathan would agree with me that if you want to have a really exciting day, you try to revise someone else’s bleb. You really have no idea what you’re going to encounter. And it’s always good to put a lot of possibiles on the consent. Possible trabeculectomy, possible tube, possible scleral patch. All the things that you might find.
[Henry] I was just going to add, sometimes it’s very hard to determine whether the bleb actually became elevated or not. Sometimes it can be very subtle. So I guess the comment here is that we assume you’re going to be measuring IOP before and after digital pressure at the slit lamp. So if you couldn’t tell the bleb’s really elevated, especially those diffused blebs, but the pressure comes down, then that’s a good sign. In that case you could probably wait a little bit longer before revising.
[Divakar] There’s a question, is anybody using autologous serum or blood for bleb repair?
[Pratap] I’m assuming you’re talking about a bleb leak, correct? Okay, yeah, I do. I use blood, autologous blood to inject. The key behind that is, of course you want to prep. I usually take it from the hand. You want to prep it with iodine so you can get everything sterilely. And then use a new needle up top, usually use a 27 gauge needle as if I’m going to needle the bleb. But when I get into the bleb with the needle, then you inject the blood under very low pressure. Because if you push hard, you can actually pop the bleb and create other openings in the conj. But you let it percolate in and the blebs are usually loculated, it’s not like one big channel. They have little loculations in them, so sometimes you have to advance it further and fill up another loculation. But I like to fill up the bleb as much as possible and then when you come out you’ll see the blood streaming out from where the leak is. And then sometimes-
[Leon] Also streaming into the interior chamber.
[Pratap] It can stream into the interior chamber, usually it does. So you always warn the patient the vision might get worse, but that usually clears up in about 24 hours. And then if sometimes you can see it close right away. The fibrin will close up right away. And other times it may not but I like to put a bandaged contact lens on afterwards, just to help act as a tamponade to help the blood seal it up.
[Leon] Okay, Divakar, do we have any final questions?
[Divakar] The only things we didn’t comment on were, is anybody using non-steroidal drops or trab? And how do people modulate their steroids if there’s a leak or the morphology of the bleb changes?
[Joanne] There’s also a question in the chat about optimal period for needling. When is the latest time you would consider just moving on to something else like a tube?
[Leon] I don’t use non-steroidals in my routine cases of trabeculectomy.
[Henry] I don’t use non-steroidals either. I try to emphasize that the patient keep doing that Prednisolone every hour to two. If you add another bottle, another drop, that compliance is going to drop very severely.
[Pratap] Yeah, I don’t use non-steroidals that often either, unless there’s some other reason to do it CME, but not. It’s an interesting question. Non-steroidals do affect neutrophil migration. So maybe there is a role in there that we haven’t figured out. But no, I don’t use them routinely.
[Stuart] I’ll use non-steroidals in combination with steroids for my combined phaco trabs. That’s about the only time for me.
[Henry] How about the question about leaks? I do modulate my steroids based on leaks. So sometimes if the patient’s one Q1 to two hours steroids and you discover a leak, you have to really drop the steroids. We may even go down as much as down to BID. But I wouldn’t stop it completely.
[Gayle] So I would just comment I agree with Henry. The trick with that is that if you have backed off on your steroids considerably to allow a leak to heal, you need to be checking the patient very frequently. Because as soon as you feel comfortable that the leak has healed you’ll probably need to go up on your steroids again, or you’ll lose the rest of the morphology of your bleb.
[Pratap] The more flow you have out a wound leak, the less flow that’s going subconj, so naturally your bleb height will start to decrease. I actually tend to use bandaged lenses in those patients as well. Because what’ll happen is the less flow you get through the leak, the better the elevation of the blb will be.
[Leon] All right.
[Joanne] Sorry, one more question from the chat was optimal period for needling. My take on that is I don’t have a time period where I absolutely won’t try revising it. And I, like some of my colleagues, will only do it pretty much in the OR. I rarely do it at the slit lamp. So I think in patients who’d had a really functioning trab for a really long time and then maybe had a bout of low grade inflammation, blebitis kind of thing, then it started scarring down, I’ll still go in and try and revise it because I think there’s a good chance that it’s reviviable. If it’s a trab that failed very quickly and immediately and the patient just has a really exuberant scarring, then I probably would just move on. Interested to hear what you guys do.
[Jonathan] I’ve been surprised that I have patients who fail at trab, five, six, seven years out. And I needle it and get another couple of years. As you’re describing, it depends on how it looks and I think the early failures are sometimes a bad sign because that’s someone who aggressively scars. Depends on how the tissue looks and that affects the timing a lot.
[Stuart] Plus I think if you have some bleeding around the flap immediately post op that can just pace that flap down and no amount of suture lysis or releasing is going to get the flap up. Those you could potentially, even if the bleb was all you could come back, because the mechanism was just that early fibrin closure of the flap, as opposed to over exuberant scarring down the road.
[Leon] Okay. Any other questions or comments?
[Henry] I think there’s another question that just got posted. What is your approach to repair bleb leaks surgically if the leak continues despite reducing steroids and trying BCL, bandaged contact lens?
[Leon] Let me hold that answer to our next program.
Thanks, everybody. It’s amazing that we kept everyone’s attention on a Saturday two hours talking about trabeculectomy. That shows how much this procedure needs to continue to be taught. There’s several indications that trabeculectomy is really the way to go. I like the new technology but don’t forget about trabeculectomy.
And we hope that you learned some pearls today that you can take to the operating theater next week. Help to improve your outcomes, that’s what we’re all about. I want to thank Ocular Therapeutix for their support of our program, I want to thank our guest speakers, Gayle and Jonathan, for their expertise. I want to thank my colleagues, our fellows, and all of you who have chimed in. So the next program in this series will be July 25th at one o’clock New York time. In that discussion we’ll talk about complications. You’ve perfected trabeculectomy, now our next program will talk about how we deal with complications.
Again, thanks so much for your attention and everybody stay safe.

August 26, 2020

Last Updated: October 31, 2022

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