This webinar will review the basic steps of trabeculectomy and how to approach each step to minimize complications. We will then review how to assess the success of the trabeculectomy, how to determine the cause of post operative complications and how to treat any post operative complications.
Lecturer: Dr. Jody R. Piltz-Seymour, Clinical Professor, Perelman School of Medicine, University of Pennsylvania, USA
Jody Piltz-Seymour: Good morning, everybody. It’s a pleasure to be here with you this morning. I know these are odd times and everybody, I’m sure is affected by what’s the COVID crisis and what’s going on across the whole world. So I just want to start by wishing everybody safety, safety for your family, safeties for your countries. And we’re happy to have this time at least to share some insights into trabeculectomy and have some time to just spend the morning a little bit and go over some ways that we can take our mind off the COVID crisis for a little while and think back about what the work that we’d love to do in glaucoma surgery.
And when we think about trabeculectomy, we think about what is success? And we have a different perspective in our patients. We think about lowering intraocular pressure, stabilizing visual function. But our patients are thinking about good vision and are they happy with their eyes, are their eyes comfortable, and maybe they don’t have to take so many medications.
We need to address both our goals as well as the patient’s goals. And we really need a proactive approach, so we can improve success rate, improve comfort by improving the profile of our blebs and minimizing complications, intraoperatively and postoperatively. And this is what we’re striving for, we’re striving for a nice diffuse bleb as opposed to what we used to see a lot more small, localized blebs or huge overhanging blebs.
We want to avoid complications like leaks, hypotony and all the things that hypotony brings on, pressure that’s too high, bleeding, encapsulated blebs, infection, pain, bleb dysesthesia. And in order to do this, we need to look at preoperative factors, intraoperative factors and postoperative factors. So intra – before you get into the operating room or before you start your surgery for sure, you want to know about your eye. You want to know where prior surgeries may have been in this area, there’s scarring that conjunctiva is not moving. But this area has nice mobile conjunctiva. So it’s important to know where your prior surgeries were, where the areas of scarring, maybe you had disruptive zonules from trauma, and there’s risk of vitreous loss. And you also want to know the degree of damage and the central corneal thickness and that’s going to help you set your goal intraocular pressure.
Some people preoperatively will stop anticoagulants. I personally like to if possible. I never want to put the patient at risk. So I always discuss this with their primary care doctor. Many times, it’s nice if you tend to stop irritating glaucoma drops if the patient gets red and irritated from brimonidine, it’s nice to stop that. You can try to pretreat with a little bit of steroids. Sometimes it’s a fine balance because your patients around a lot of medicines they may get confused if you give them new pre-op drops, those steroids may raise the pressure if they had – and they already have high pressure to start with. So it’s always a balance. We certainly want to try to control lid abnormalities, blepharitis or other lid conditions, like, in this patient with the entropion.
We want to maximize exposure. I find a corneal traction suture works best. Most people do this with a vicryl suture, which is very hard to control. If you use a silk, an 8-0 silk suture, it’s nice and easy to control. We definitely want to betadine prep. And we want to use powder-free gloves, which I think most gloves are.
Let’s go back here for a second. We want to be careful with using antimetabolites in people that are a high risk for hypotony. We’re going probably to use them but we’re going to use them very judiciously in young myopes and an elderly white patients for sure.
I’d like to encourage people to inject the mitomycin rather than use a pledget. It gives you a more diffuse application and it’s actually just easier than having to worry about pledgets. Every now and then, I’ve heard cases where pledgets have gotten lost, hard to find, you put them up into the – up through a fornix – through a peritomy into the fornix and people had sometimes trouble finding small pieces. So I don’t see a big downside to injecting the mitomycin other than the small risk of subconjunctival hemorrhage. I like to dilute the mitomycin, 2.1 mg/ml. And I dilute it with lidocaine. And I usually inject 1.2 cc subconjunctivally. So it’s a low concentration and a bit of a bolus (phonetics), so it diffuses, use a 30-gauge needle.
For re-operations, you can go higher. There is a risk of mitomycin toxicity. And that’s where it looks avascular. And so if you use too much mitomycin or the eye has a sensitivity, the conjunctiva will go white and thick and leathery. So it looks avascular, but it does not filter. So I like to err on the side of lower dose especially for first surgeries.
Here we go. And if you’re using a pledget, use a large pledget. And I like to try to get a single large piece in there. I haven’t done this in quite a long time because I pretty much always inject. But if you are doing a pledget, use a large piece. And this was a re-operative case with a limbus-based trab. And we’re going to just move on from here.
Intraoperatively, you want to handle the conjunctiva very, very gently. You want to use non-toothed forceps. And in general, we try to avoid a tenonectomy. Tenons is actually your friend in terms of keeping you from having a very thin avascular bleb.
Just let me take a quick peek at these questions. So, someone asked about a patient that has had a trabeculectomy three weeks ago, that has a pressure of 10 with an absent bleb and normal pressure and normal AC. Sometimes your pressure can be low from an – it can look like the bleb is absent if there’s some inflammation in the eye. You could have some aqueous shutdown. But I’d really be concerned or not concerned, but I would ask you to check to see that the bleb is not just a low-lying diffuse bleb, which is really lovely. So, sometimes we don’t get the big elevated bleb. We actually don’t want to get a big elevated bleb. We want the fluid to percolate very gently. So, you could take a slip beam of light. And just see if there’s a little bit of gap edge between the sclera and the conjunctiva, where a fluid could be flowing nice and smoothly. Even though it does not look like an elevated bleb. I’m going to minimize those for a minute.
I think what I’m going to do is go through a little bit of the talk and then we’ll come back to the questions before we go into the second half. And we could just stick with the first half if there are lots of questions.
For a Fornix-based flap, which is what most of you are going to be doing. We have a peritomy, and we’re going to try to keep that peritomy relatively small. And if mitomycin was injected, you don’t have to do a large conjunctiva dissection. You just need to make sure that the conjunctiva has no tension when you bring it back to the limbus. And remember, while you’re doing this, your eye may be rotated down. So when you check for tension, you want to release the traction suture to make sure the conjunctiva can just easily fall back to the limbus. You want to be sure to place your peritomy superiorly or slightly temporarily. If you can avoid the nasal area, it’s better because when patients have extension of their blebs into the nasal area, they tend to have more likely have bleb dysesthesia. And this is just an edited version of a limbus-based – I’m sorry, a fornix-based flap, there it’s your peritomy, not too big. And I’m looking to see how much traction, I want to loosen it up a little bit. But you don’t need to loosen it up a lot. And here we could just see another patient, and I’m just checking to see that I have no tension. I can bring that back up to the limbus with no tension whatsoever.
What about the limbus-based flap, most people don’t do this anymore. I still actually like them very, very much. They allow watertight closure, your risk of blood leak is not, never zero but near zero, very, very, very low. The key – so limbus-based flaps used to get a bad reputation because they used to lead to localize blebs where there was a scar line. But if you make your incision far back 10 mm posterior to the limbus, and you use a large pledget of mitomycin or better yet inject mitomycin, you can develop the same kind of beautiful nice diffuse bleb that you can with a peritomy. The surgery is a little bit more challenging. It’s nice if you have an assistant but it’s a nice technique to know because your risk of wound leaks are very, very small.
And this is just a little video showing a limbus-based incision. See how high up I’m in the fornix and you cut through tenons and cut through conjunctiva, go all the way, push all the way up to the limbus. And then when you try to get up to the limbus, you see a nice blue zone right there. The conjunctiva has already released all the way up to the blue zone. You want to be sure to release your traction suture, so the eye can rotate back. And that way you can have nice exposure up to the limbus.
Now, in terms of making your – once you make your peritomy, you want to make a scleral flap and try to avoid old surgical sites or areas of conjunctival, scleral thinning, use some cautery. But I don’t like having bleb, but you don’t want to have too much cautery that you can track the tissues. Once you get good at making a scleral flap, you don’t need it large, three to four millimeters is fine. And to form this flap, a third to two-thirds of scleral thickness.
I’d still make a flap where I delineate the soft sides of the flap and then dissected forward. But I find in teaching, most people have a lot of experience with M6 and they can do a beautiful scleral tunnel. And that’s all you really need. You make a nice scleral tunnel and then you cut the two sides up and you have a beautiful trabeculectomy flap.
And this is just, again, a very quickly edited version. You’re going to see that cuts happen very dramatically, quickly to delineate the two sides. That was after a little bit of quartering. And this is one point that’s very, very important. I want you to see how far forward we go here. We want to get into that corneal lamellae (phonetics). You see how the tip of that blade is all the way up there. That’s very important. You want to be far anterior into clear cornea.
Peng Khaw has talked a lot about the Safe Surgical System. I agree with a lot of what he says, it’s nice to try to get fluid moving posteriorly. I don’t agree that he says you have to do it with a peritomy, not with a limbus-based flap. But certainly it’s nice to get the flow posteriorly.
When you – after the – when you will go to make your sclerostomy, I like to replace a paracentesis. And I like to preplace an apical suture and enter very far anteriorly. We want to place, as I mentioned this sclerostomy as far interior as you can anterior to trabecular meshwork. I know this is called the trabeculectomy, but it’s really a cornuectomy. We really don’t want to punch as far back as the trabecular meshwork because there is vascularization in there. We want to do our punch mostly within clear cornea. You want to re-pressurize the globe as soon as possible after tying the apical suture. And you can keep the chamber maintained with viscoelastic or an anterior chamber maintainer. You don’t have to, you can just do your punch, close it up fast and re-pressurize the globe. I would not advise this in patients that are at high risk for suprachoroidal hemorrhage though.
Most of the time, I do use a viscoelastic and you have to be able to get it out of the eye in order to assess – after you close the flap you want to get it out of the eyes so you can assess the amount of fluid flow through that trab side. And if you’re doing a surgery combined with cataract surgery, you want to leave the viscoelastic in the eye until it enter your chambers, until you – until after, you want to leave the viscoelastic from the cataract surgery in the eye until after you do the trabeculectomy.
Iridotomy are optional in many cases. I don’t do an iridotomy if I’m doing a combined with cataract surgery, I don’t do it with pseudophakes. And I don’t do it in high myopes and have deep anterior chambers. I would suggest that you avoid doing it in aphakes eyes or an eyes with prior complicated surgery and especially, complicated cataract surgery. Your iris acts as a barrier to keep the vitreous back. So if you don’t know what went on surgically behind your iris, better to leave the iris there than doing iridotomy and find vitreous coming through your iridotomy.
I’m going to back and this is just showing, let’s see, I’m just closing the – I’m putting here preplaced apical suture, making a paracentesis. I put some viscoelastic in and punch, punch. Now, this punch, I will show you goes almost a little too far back but it’s still good, still in the blue zone. So you want to do all of your punching in the clear cornea part before you anterior to the trabecular meshwork.
So, for your scleral flap, use multiple sutures. Here are three permanent sutures. Here’s a permanent and a releasable suture. And then you want to assess your filtration, intraoperatively and adjust. You want to aim for your ideal postop intraocular pressure. You want to adjust your suture tension intraoperatively using adjustable sutures or if you have your releasable you can adjust those as well. And you have to prepare for how you’re going to manage the pressure postoperatively, whether you’re going to do laser suturelysis or use releasable sutures. If you don’t have access to a laser, you know, you have to do releasable sutures.
So, releasable sutures, there are many different techniques, the one, that’s used most commonly – sorry, is to make a small pass in the cornea come out, then make another pass into the cornea and come out, actually it come out here and then make your regular pass through the flap and through the bed. Three or four throws on your needle holder and pull it down and you should have something that looks like that. This is another technique where you just go up through the flap, back down and sew it on the cornea, both work quite nicely. You want to evaluate and adjust your suture tension to obtain your designated intraocular pressure. And what you need to do here is you have to make sure if you use viscoelastic, the viscoelastic is out of the eye, pressurize your globe with BSS, then test the globe and see how firm it is. Some people use the BSS bottle. I tend to use my finger. And I just test the eye and see how firm it is. You want to make sure there are no leaks at your paracentesis and no leaks at your traction suture site. And then you evaluate the flow through the trabeculectomy site.
So here, we’re putting in multiple sutures. And I just want to take a second to show you that is an adjustable suture. So let’s watch it again. This is in real time, so you single pass through there. You’re going to make a single throw on your needle holder, a single throw. This is to make an adjustable suture, not a releasable and adjustable, single throw. Now, you’re going to come underneath there, underneath the suture and around. And you’re not going to move your needle holder, you’re just going to slide that knot over and down. And you know, that is a slippy knot, so it’ll hold. You can take the viscoelastic out and you can adjust. Here, I’m checking the pressure. I will have tested my wombs. I pressures a little too high, so I’m going to loosen that suture. Loosen that suture, I’m going to recheck my flow, maybe put a little bit more fluid in the eye, test it and just evaluate the flow, a little bit more BSS and see how it flows. I can see fluid coming out right there. And then I’m going to tie my sutures down when I get them to the place that I like I’m going to put two extra throws in. And then you want to be careful when you put these extra throws and not to pull too tight because you don’t want to tighten the suture. So you just want to place those knots down. If you can vary the knot trim and vary the knots, that’s great.
And then, of course, you want to just double check your flow at the end. So you see how that’s just wetting the wedge cell and the wound is just in that little gap-edge. There’s just a nice little bit of flow each time, it just relax a little bit. That’s exactly where you want to be, just a little bit of rewetting at the side.
And then you need to close your conjunctiva. There are multiple techniques. I tend to keep it simple and use wing sutures, like when you have the short cord length in your peritomy, you can usually get very nice closure with just wing sutures. And I like to have it overhang the limbus and have it be quite taut. I use 9-0 nylon. I don’t use vicryl because I like it to stay nice and secure. And I tend to use two sutures on either side with buried knots. You really want to try to bury these knots because otherwise people are going to be very, very uncomfortable. You can do wing sutures with a central mattress suture. I find sometimes that that destabilizes the traction across the limbus. Some people use a running mattress across the limbus and other people leave a small lip of conjunctiva at the limbus and then do a running suture conch to conch. You have to find the technique that works best for you.
And so this is two wing sutures on either side, quite speeded up. But you see how my knot is buried. I don’t have to rotate it. By coming under the conch first and then through the peripheral cornea that knot will automatically be buried. And then I would like to anchor two extra sutures in. When you have a short cord length, you generally don’t have big relaxing incisions. I tend, when I make my peritomy, I don’t make a big relaxing incision. And you see we injected fluid here and look how lovely that bleb elevated side on negative at the limbus.
Now, if you have a limbus-based trab, you can do a running mattress. You can do it one or two layers. I like to do a quick technique where I anchor the needle, then I hold the needle up and I just go in and out like a mattress suture. I placed the conch on the needle rather than sewing this way, my needle stays still and I placed the conchs on the needle. I’ll see how clearly we can see this. So here, the suture is already anchored. And then I’m going to go in and out with the mattress. So now, I’m going from out to in, from in – here, from in to out, and out to in. And then, in the inferiorly, in an out and out to in. And you just place all the conjunctiva on the needle itself and you can do the whole wound, sometimes in one or usually two passes. And it slows down quite nicely.
Let’s see. And it can pull and you can cinch it up so that it’s sort of shortens the wound, which gives horizontal as well as anterior-posterior pressure to that wound to keep it watertight. And it’ll stay that way. And this I generally do with vicryl because it’s just easier and you don’t need to worry as much about leakage. And you’ll see it’ll cinch up. But over time as the vicryl releases, it’ll smooth out again and it’ll actually move a little bit more posteriorly. You’ll see when I tie it down here, how it will cinch up and grab on that side, so you can tighten it up, pull it down. And it cinches up so nice, so it won’t leak. And all those sclera will go away and it’ll all loosen up and fall back as the vicryl loosens over the next couple weeks.
So, some things to be cautious about intraoperatively, you want to minimize the risk of choroidal hemorrhage by slowly decompressing the eye. And you have to be very prepared for the worst, especially in patients with Sturge-Weber or nanophthalmos and take things very, very slowly.
You want to use vigorous topical steroids. So if you’re using prednisolone and if it’s the acetate, you need to really instruct your patients to shake that bottle a lot and use it eight times a day. I tried to use difluprednate, durezol, and we can use that six times. Brief topical antibiotic, we want to discontinue systemic carbonic anhydrase inhibitors if the other eye is safe enough to do that. I tend not to use cycloplegia. But certainly, if it – unless it was a chronic angle-closure patient. And then cycloplegia is important. You want the patients to avoid coughing, avoid valsalva. You want to keep their head above their heart and you want to be prepared to modulate flow in the post-op period.
So, modulate flow, you can do a little bit of digital pressure. And I do it very, very gently. I just have the patient look down, my fingers on the lid and I give a little press on the side of the bleb. And that’s only if the bleb doesn’t look elevated or if the pressure is higher than I like. You want to modulate flow by giving lots of steroids; you want to keep that flow down. And then we do laser suturelysis or we pull releasable sutures when we don’t see the bleb the way we like it to look or if the pressure is too high.
But if you want to try to avoid releasing any sutures that first week, you want to try to get them out to two weeks because you don’t want to do it too soon, the pressure can go too low and we much rather have a little higher pressure than a little lower pressure much easier to deal with. And even if you started at two weeks and you cut one, you wait a few days you cut another. You wait a few days, you want to be very cautious if you have three stitches in there to cut the last – well, however many sutures. You want to watch for cutting that last suture, not to do it too early. Try to get out to at least three weeks. Sometimes you have a stuck flap where there’s just fibrin glue sticking that flap down. If you have access to tPA (tissue plasminogen activator), you can unstick the flap with a very tiny amount. I would – it’s very rare to me that I’ve only needed to do that a few times in my career.
Cutting stitches with the laser Argon or Krypton. There is a way also to do with a diode. There are multiple lenses available.
There are lots of questions coming in. I’m going to get through this first half of the lecture and then we’re going to spend some time on the questions. And we can see if we need to go to the second half of the lecture just spend the time answering questions. So, there are multiple lenses available. I like this blumenthal lens. It really focuses and really can pinpoint where the suture is.
So, performing a successful trabeculectomy requires pre-planning. There are lots of risks and we really want to try to diminish those risks. And it’s very, very important to be meticulous, plan ahead, every step that you’re doing is important. But it needs to be individualized for each individual patient because every patient is unique. But I want everyone to – as you work through this that success can be maximized and complications can be minimized if you really plan ahead and watch each step as you do it.
Okay. Let’s go to the videotape here. Okay, let’s see. Okay, let’s see. So, one person noticed that their patients always ended up with hypotony. Any tips? So, a couple of things, you want to make sure you have a nicely formed scleral flap, not too thin. And you don’t want to have too much cautery because cautery will shrink the tissues and the flap won’t sit back in the bed. You want to solve it so the trab flap down with multiple sutures and you want to test it in the eye. If you can keep a formed chamber in the operating room, your patient’s going to have hypotony. So you want to check and adjust those sutures intraoperatively to make sure that the eye has a good pressure and that’s my best advice on that.
How do you prepare 0.1 mg/ml concentration from the powder? You know what, I’d have to look that up because we always get it already diluted down to 0.2 or 0.4 mg/ml. So I’d have to do a little algebra, if I find out what – about the powder and we can get back to you on that.
There’s a question about whether the mitomycin should be injected under or into tenons? And I don’t really think it matters so much. I know we hear a lot about being above or below tenons when it comes to XEN implants. But for mitomycin injection, it really doesn’t matter. We just want to flip up, you know, elevate the tissues there and let it have time to percolate. If it’s in the tenons, it’s going to be affecting the surface of the conjunctiva and affecting the sclera. So I think that’s one thing we don’t have to worry about.
What is the best site for the sclerectomy to avoid valving? So there’s a lot of different thoughts on this. Sometimes valving is not the worst thing, as long as you can demonstrate that you have adequate flow. In fact, some people will make a scleral tunnel, a short scleral tunnel and do a punch and not even cut up the side, so it does valve a little bit. But you have to be able to establish the amount of flow that you want in the operating room.
So, one problem that happens with valving is that you don’t cut their sides up far enough, so that there’s too much overlap. So, if you’re having a problem getting adequate flow and you feel that it’s from valving, bring your scleral flap sutures up a little farther.
Do you use atropine? So, do I use atropine? I only use cycloplegics in chronic angle-closure glaucoma patients at this point. I used to use it routinely. There’s nothing wrong with using atropine. And you can play it by ear, if the chamber staying deep and you’re using atropine, you can discontinue it after a couple of weeks.
And then the next question is about stopping glaucoma medications before you do your trab? That’s a hard one because usually you’re doing the trab because the pressures are high or the patient’s glaucoma is getting worse, so it’s hard. So I don’t always stop glaucoma medicines beforehand. Again, this is one of those situations where you have to play it by ear for that patient. If it’s not safe, don’t do it. It’s going to be a little harder to adjust to know your flow postoperatively because the glaucoma medicines are still on board. And so you just have to – but if you have medicines that you know are irritating to that patient’s eyes, particularly, brimonidine, sometimes like the prostaglandins or the ROCK inhibitors, you may want to try. But again, if it’s putting your patient at risk for high pressure, you don’t want to do that.
Thanks for the greetings. Do I need to go for suture lysis or just wait with the pressure of 10? So with the pressure of 10, I’d be very, very, very cautious to do suture lysis. So, this is going back to that first question, where the patient had a pressure of 10 but it doesn’t look like they have much of a bleb. I would first check for inflammation in the eye and make sure there’s no inflammation, maybe check for cyclodialysis cleft or check for choroidal (serous choroidal). Because sometimes you can have a far peripheral choroidal and that can drop the pressure without shallowing the chamber at all. But I would think very, very strongly suggest that you look and see maybe you have a better bleb than you think. Maybe it’s just a very diffuse low-lying bleb. I would watch carefully, I would keep the steroids going.
What is the suggestion for surgery with rubeosis? If there is active iris neovascularization, trabeculectomy is not a good idea. Glaucoma drainage tubes are much better. You can try to get the rubeosis to go away with intravitreal VEGF inhibitors and then consider trabeculectomy. But usually, time is of the essence. So if you need to operate when there’s active rubeosis, I would do a glaucoma drainage too. But I would still try if you have access to anti-VEGF medicines, get an intravitreal injection before you do the glaucoma drainage too. Things just work so much better when that rubeosis is in the resolving phase rather than the active phase.
Oh, this is a hard one. How do I identify the limbus in advanced ophthalmic cases? It’s hard. It’s really, really hard. For doing a trabeculectomy, you’re just going to most likely make a peritomy and you’ll see where that iris inserts. You may wind up doing your entire scleral flap in the blue zone and that’s not uncommon. But as long as you can get the conjunctiva backup to where the limbus was, where you removed it, you should be fine. So, in these cases, the blue zone, everything is so stretched that the blue zone can be so big, but it’s fine. Even if you do your whole trab flap mostly in the blue zone, that should work fine anyway.
I do my trabeculectomy under topical anesthesia. Except in rare instances, and then I use peribulbar anesthesia. But you don’t have to do, especially, when you’re starting first, starting to do trabeculectomy, it’s a very good idea to have a peribulbar block. But once you are used to doing it, topical is fine.
How do you massage postop? First of all, I’d like everyone to try to forget the word “massage” because massage implies that you’re moving around, where you’re really just doing digital pressure. Because if you tell your patient to massage the eye, they can start rotating around and they can hurt their conjunctiva tear sutures and things like that. So I’d like to try to talk about digital pressure. And basically, I just have to make sure the patients wash their hands. Oh, if they’re doing it by themselves, if you’re in the office doing digital massage, I have the patient’s look down, I put my finger on their upper eyelid and I just give a little pressure through the globe, through the lid on the globe right next to where the trab flap would be or a little bit above.
You can also press right in the center of the cornea. Have them close their eyes, put their finger on the middle of their eye, look straight ahead or you put your finger and press straight back. And that sometimes works quite nice. It doesn’t deform the scleral bed, but it pushes the fluid from the anterior chamber out the flap. And sometimes some globe respond better to digital massage from above, some respond better from straight ahead. You have to if you’re teaching the patients to do it or when you’re doing it for the patient, you have to remind them to look straight ahead because if they just close their eyes and you press, there’s a Bell’s phenomena. So you put it on, have them look straight ahead and that way you’re pressing through the closed lid on the clear cornea.
Post-trab patient. Sometimes, I find post-trab patient with releasable sutures buried under the corneal epithelium. The surgery was three months prior with controlled IOP. Would you still try to get the suture out or leave it in? So, if it’s the kind of releasable suture where it’s a three or four throws and then pulled up a little slip-knot kind. If the pressure is good, I would not remove the suture. But what you can do is you can get it out of the cornea. You can – if it’s in a first little scleral – corneal paths, you can pull it out of that and then you give it a little bit of tension and snip it right at the base of the cornea and it’ll retract up, just so you don’t have – you don’t want to have a suture exposed on the cornea for a long period of time. So if you’re three months out, you haven’t had to pull that releasable, just cut it so it can just retract without actually releasing it.
When do I prefer a limbus-based conjunctiva flap? If I have, I mean, and this is my preference. This is not what the vast majority of glaucoma surgeons do. But I know that I can get a beautiful diffuse bleb with a limbus-base flap. I know it’s going to take me more work in the operating room. But I know that my postop course may be easier. So, my criteria is, if I have good exposure, if I have nice mobile conjunctiva that is not too thin and if I have a good assistant. So if I don’t have someone that can help me that I know and work with, I don’t do it. So you’re much safer to do a peritomy a fornix-based flap unless you have a good assistant.
How long do you wait to enter for choroidal drainage to choroidal detachment drainage? So, if you have serous choroidals, you want to try to weigh them out. Most of the time, they will go away. If you use a high dose of mitomycin and the bleb is extremely exuberant, it might not go away. But for choroidals, and this is something I get to in the second half of the lecture, which I hope you have time for. If we’re a serous choroidals, you really want to try to wait it out as long as possible. You can’t wait it out if the chamber is flat, if you’re losing your bleb or if you have kissing choroidal that are there for a few days, you usually need to drain them but or if the patient needs rapid visual recovery, this is their only eye. They had a patient one year that had to get the crops into the fields before the season started and it was his only eye. And so that’s another reason, just logistical issues.
Maybe this is a good time to take a break from the questions because I still see I have a lot of questions. Let’s do the second half of the talk because it talks a lot about this postop complications and how to assess. And then we’ll come back to some questions. How is that? All right, let’s see if I can figure out how to get back, there you go.
So, assessing the post op filter in the early and late periods. Oh, we have some questions, that’s right. What is a common cause of low pressure with a flat bleb in the early post-operative period? Wound leak, exactly. So the majority of people said wound leak. So if you had overfiltration, you would expect to see a large bleb. And if you would have suprachoroidal hemorrhage, you would have usually an elevated pressure.
All of the following are associated with elevated IOP and a shallow anterior chamber except suprachoroidal hemorrhage, encapsulated bleb, malignant glaucoma or angle closure.
Very good. So, an elevated pressure and a shallow anterior chamber, you would not see that with an encapsulated bleb. Encapsulated blebs gives you high pressure but a deep anterior chamber. But the other three would. And the most common cause of low pressure and an elevated bleb is overfiltration, choroidal effusion, inflammation, and/or retinal detachment.
Beautiful. So, I think we can all go home now. You have the overfiltration, it’s the right answer. Almost everybody got that. Maybe we can skip the lecture.
So here, we’re going to identify the various complications in the early and late postoperative period. So, when we’re in the early period especially, and we’re assessing the postoperative filter, we want to assess many things. We want to look at the pressure. We want to look at the appearance of the bleb. And we want to look at the anterior chamber depth. Of course, we still want to look in the back of the eye and we want to assess the anterior chamber inflammation in that as well.
But the most thing, the things that we’re going to concentrate right now or pressure, bleb appearance and anterior chamber depth. And here, let’s just look at these blebs for a second. This is a nice diffuse bleb. You can see our flap is here and a nice low-lying bleb. This is a diffuse flap, but it’s a little bit avascular and a little bit off to the side. I like them just a little bit higher. And this is one of those older blebs that had a scar band through anterior, so it formed a localized bleb. This is the reason, blebs that look like this is the reason that limbus-based trab got a bad name because they used to perform them like this. But if you say again, high in the fornix, you should be able to do a limbus-based trab without forming a bleb that looks like this.
So, in the early postoperative period, if you have a low pressure and a flat bleb, you have to be very concerned about inflammation, a wound leak, choroidal effusion, and cyclodialysis cleft. So inflammation, you can get aqueous shutdown and the pressure just goes very, very low. And so this is about similar to that case that we were talking about earlier with the pressure of 10 and the flat bleb. These are the things we want to be looking for.
So, bleb leak, we try to prevent it with meticulous wound closure. We can try contact lens or patch or glue. If it’s leaking, we can try to use some aqueous suppressants, a contact lens. Here’s a large diameter contact lens. But eventually, if you have it longstanding, you may need to do a conjunctiva flap revision.
Coronal effusion, here’s a serous choroidal in the periphery. You want – as we were talking about just a few moments ago, we want to try to treat these conservatively, unless you have a flat anterior chamber or your bleb is failing. Try to be patient, stop beta blockers and carbonic anhydrase inhibitors, if you can, both in that eye and in the contralateral eyes, so there is crossover from beta blockers. There’s a weird phenomena, where even contralateral carbonic anhydrase inhibitors can cause serious choroidal. So if you can stop these in both eyes, that is great, you do the best you can. If they require it in the other eye to maintain pressures, you can. And we generally do cycloplegia.
Some vigorous steroids are often needed because very often it’s associated with inflammation. Some people use systemic steroids. There is really no good study that shows it’s helpful. But sometimes you can try it, you can – if the chamber is shallow, you can reform it with viscoelastic usually or you can use gas. And only in rare instances where you need to drain them, drain and reform the anterior chamber.
I would caution you though, that if you just go in and drain and reform the anterior chamber, you’re at significant risk of having them recur because they occurred in the first place, usually because of overfiltration. If it was just because of inflammation and you control the inflammation or you develop some scar tissue just from having the choroidal and the hypotony, you may be okay. But I would certainly intraoperatively watch about and check to see if you need to resuture the flap — the scleral flap.
If you have a cyclodialysis cleft, you can look at this through gonioscopy. It’s better if you have some pilocarpine or viscoelastic in the eye. If you have access to ultrasound by a microscope, you can use that to visualize it. You can fix this sometimes with cycloplegia, not one as big as this for sure. Some laser diathermy, very often you have to just go in and surgically close these. But it’s they’re pretty unusual. And you have to be where the pressure usually sheets up super high after you close them.
So, in this early postoperative period, when you have the low pressure and the flat bleb, you have to be aware of bleb failure. So you have to watch and make sure that your bleb is not failing because of a wound leak or choroidal effusion or the like.
What about low pressure and an elevated bleb? Everybody, and almost everyone knew this is overfiltration. So, what do you do if you have overfiltration? You can try a pressure patch, you can try a large diameter contact lens. If the chamber is shallow, you can reform with viscoelastic. You can try to decrease your topical steroids. Again, here you can talk about draining choroidals and re suturing the flap.
We tried to give it some time, again, but used to be before mitomycin, you could wait almost anything out and it would reverse, you would get more – you were able to elicit scarring. Sometimes with mitomycin trab, you can’t. So you have to be cautious.
So you want to treat aggressively, if there’s lenticulocorneal touch, if there’s corneal decompensation. So if you’re starting to get lose your cornea or lose your bleb, you want to treat more aggressively.
If you have kissing choroidals with blood in the vitreous, some people say that kissing choroidals by themselves with their touching that that’s not a problem. It’s more of a problem if there’s some blood in the vitreous, which then makes them seal together. Again, you can drain the choroidals, if you need rapid visual rehabilitation. And when you drain you often need to resuture the flap.
What about high pressure, a flat bleb and a shallow chamber? This is the bad scenario. This is what you really don’t want to see. These are the bad things. Suprachoroidal hemorrhage, malignant glaucoma or angle closure. Suprachoroidal hemorrhage is a sudden onset of pain. Intraop, if it happens, just close the eye. And this is when you are happy that you have that preplaced suture. You just close the eye and try to pressurize the eye as much as you can. Postoperatively, it develops supportive therapy with analgesia, try to get the pressure down with aqueous suppressants and cycloplegia. It’s no sense going into drain it. If you try to drain it right away, by the time you get into that already clotted, so watch this and drain when there’s ultrasound evidence that the choroidals are liquefying. Yeah.
What are predisposing factors for choroidal hemorrhage? Well, quite a few things as this list would indicate, but certainly older patients apex thin myopes, high myopia, buphthalmos. Coughing and valsalva is kiss- it’s really a high risk. The thing that causes suprachoroidal hemorrhages more than anything else is straining when moving your bowels. So, when people, when I talk about postop instructions for my patients, I’ve talked about the bathroom every single time because the one time that the most common time to get a suprachoroidal hemorrhage is when people strain moving their bowels.
What about aqueous misdirection? There’s a lot of different names from malignant glaucoma, aqueous misdirection, there are a lot of different theories. Some people think it’s not really aqueous misdirection, but the clinical picture is that you have a shallow chamber, even centrally, the whole back of the eye moves forward. The chamber is shallow, the pressure is high, you have iridotomies, they don’t help. So, we can try medical therapy, laser therapy, and surgical therapy. About half the cases will respond to medical therapy and the key to medical therapy is cycloplegia. So, atropine, atropine, atropine and aqueous suppressants, so you can try some hyperosmotic, some steroids, and you can try it’s usually if you have a pseudophakia, it’s very easy to yag the hyloid face. You can also do it through an iridotomy of someone phakic.
You can try ECP to shrink the ciliary processes, but if you have a case that will not break with conservative therapy, you need to undo surgical therapy. We used to talk about a vitreous tap or pars plana vitrectomy, but they can re- it can redevelop after either of these. You really need to develop some type of unicameral eye. A pars plana vitrectomy with an iridocyclectomy, you have to be able to get from the, get your vitrectomy probe from the back of the eye to the front of the eye or vice versa. You need to have an opening from the anterior chamber all the way into the vitreous cavity and iridocyclectomy or move the zonules in that area and everything.
You can have an a unicameral eye that way. You can also have a unicameral eye by taking out the interocular if the patient aphakia and you have a single chamber they can be a malignant glaucoma. In the end, you can also put a glaucoma drainage tube into the vitreous cavity certainly after a thorough vitrectomy and that will keep the fluid, keep the eye from having the shallow anterior chamber.
Pupil block were used to, this is the least of the bad of the three bad things. You can perform an iridotomy, lower the pressure, control inflammation. If you’re having trouble breaking the attack with and can’t get an iridotomy and you can sometimes do a pupilloplasty.
Okay. What about high pressure, a flat bleb and a deep chamber? That’s usually, you’re not filtering, so you have a tight flap, your sclerostomy may be blocked or your flap may be stuck. So, with tight flap, you first always check gonioscopy though first to make sure that there’s nothing blocking the sclerostomy. If there’s nothing blocking the sclerostomy you can try a little digital pressure. You want to get lots of steroids and you want to do laser suturelysis or pull releasable sutures.
Again, you don’t want to do that too soon but you have to. If your pressure is very high, you may have to do it much earlier than you would like to. A stuck flap that’s when the, if your sutures know they’re loose, maybe it’s later on and you’ve already cut some stitches, but the flap is actually glued down. You can get more steroids, you can again try digital pressure, just try to give it some time. And in rare instances, you can use tissue plasminogen activator either intracamerally or subconjunctivally in a very, very tiny dose, like point one two micrograms or even 0.6 six mcg. And you can always try blood needling just go in subconjunctival with a 30 gauge needle or 27 gauge needle and just lift up that flap a little bit.
Bleb needeling is for late failures you can come in or even earlier in the postop period, after mitomycin injection will come in from the side or higher up in the fornix and you just want to get underneath that flap, lift that flap up, I usually like to come in through this sclerostomy and see my needle in the anterior chamber. And here we just have here we’re injecting some mito, we’re coming in with our needle high up in the fornix. And that’s why I still like to do my blood needles in the operating room. I feel like it can be more aggressive. And we want to pass underneath the scleral flap, see it in the anterior chamber, break up scar tissue by wiggling your needle back and forth as you go in and out. And then you can see a nice elevated blood back there.
Sometimes you can have a block sclerostomy, can be blocked by fibrin, it can be blocked by iris, it can be blocked by vitreous. If it’s blocked by fibrin try to wade it out, steroids this is where tissue plasminogen activator is lovely. Again, you’ll rarely need this though, you can usually just wade it out. I’ll often give a little subconjunctival injection of decadron at this point, if I see lots of fibrin. If the iris is blocking the sclerostomy, you can try laser. If it’s vitreous, this is probably not going to work. You have to get in with a detector and get it out because your flap is likely going to fail.
What about in the early postop period if you have a high pressure and elevated blood and a deep chamber? One second to think about that one. And this is your encapsulated bleb. This is always so disappointing because everything’s usually going well. And then at a month out, the bleb gets high, domed and thick. Sometimes things weren’t going so well at first, sometimes it’s you have hypotony and the pressure is low maybe have some choroidals, and then you get the choroidals to go away, the pressure equalizes and the next time they come back, they’re in this kind of scenario. These are encapsulated blebs, they’re domed shaped, they’re thick walled and the fluid gets into them and then can percolate out. More common when we use 5-FU compare to mitomycin and as it says here it’s often a sequelae after hypotony.
Generally started about a month, treat these with heavy aqueous suppressants, you want to soften the blood, soften the eye and then that bleb wall can start to percolate fluid again. Some digital pressure, some steroids, we’re not sure if the steroids are going to help or raise the pressure, it’s hard to know. And then you may try bleb needling or you may need to do a revision. Sometimes if you have an encapsulated bleb and you want to go and do a bleb needling, you can find a spot where it’s not encapsulated and come in near the limbus and you can extend it outwards. Sometimes just needling an encapsulated bleb, it’s going to rescar right away and reform. So, that’s the early postop period, the late postop period, this could be a whole separate lecture. So, we’re just going to go touch on a few things.
In the late postdop period, you can have too much flow, you can have too little flow, you can have infection, and you can have pain. We have a lot of questions coming in, I’ll stay until 10:30, so we don’t have to rush through them but we can try to get through as many as possible. And if you have hypotony in the late postop operative period it can be from over filtration, it can be from recurrent inflammation, wound leak, serious choroidals, a lot of similar things to the early postop period.
You want to check the retinal detachment, cyclitic membranes, some drugs, it can be from ocular ischemia or you can have some ciliary body toxicity of the mytomicin C. So, sometimes that might mitomycin can actually damage the ciliary body itself through transscleral flow and you can have less aqueous being made. Having hypotony can lead further to further complications. Maculopathy it can lead to serious choroidals. Serious choroidals can cause hypotony, hypotony causes serious choroidals and you can get into this loop. It can cause bleb failure. You can develop corneal edema and corneal decompensation, shallow/flat anterior chambers, inflammation, post peripheral anterior synechia, cataracts certainly you can develop from hypotony and the worst suprachoroidal hemorrhages.
Hypotony maculopathy is a serious problem. We see it more with high myopes people within sclera. The problem with hypotony maculopathy is that it causes immediate visual compromise. And so, sometimes you’ll take a patient with good vision and you say we need to do trabeculectomy because we want to save your vision and you give them hypotony maculopathy and you give them immediate bad vision as opposed to theoretical future bad vision.
So, with mitomycin, very often these will not reverse on their own. So, you can watch for a little while, you can cut back on the steroids. But you need to act a little bit more aggressively on these because they can – if you don’t act within the first few months, your chances of getting good vision back decrease. So, you want to stop the aqueous suppressants even in the contralateral eye if you can, you want to decrease topical steroids. Other things like external compression and trying to scar it up usually don’t help. And very often, you just need to go back and put more sutures in your scleral flap. If it’s happening from a – whatever the issue that’s causing, if there’s a wound leak or something like a retinal detachment, you certainly have to treat that. But most of the time it’s over filtration and you need to go back in and resuture your flap. You can take the conjunctiva down and put a suture. And sometimes you can suture right through the conjunctiva and put the stitches down and that suture will work its way through the conjunctiva.
If you have a bleb leak, we see that more commonly with the use of antimetabolites, higher dose antimetabolites, when you have thin avascular or localized blebs. There’s a lower incidence when there’s diffuse blebs and that’s why it’s good to do those inject the mitomycin to get a diffuse application. And we can see it with a seidel test. And sometimes they can be subtle. We want to treat blebs leaks because they can lead to infection and they can lead to hypotony. But the risk of blebitis with a bleb leak is much – bleb leaks greatly, greatly increased the risk of blebitis and the risk of endophthalmitis.
So, treating a late stage of bleb leak is different than an early bleb leak and an early bleb leak you just normally have to watch it or go back in and close it. Late bleb leak, there’s a little bit, they’re less likely to close. But you want to use aseptic wipes and like I have my patients use an aseptic wipe on their eyelashes every night to decrease the periocular flora. Here we have something called OCuSOFT plus or there’s hypochlorous acid wipes that are very good at decreasing the bacterial flora. I give aqueous suppressants, you can try pressure patching, you can try a large-diameter contact lens but you have to be very cautious with the contact lens in an eye with the leaking bleb and risk of blebitis. Some people will use doxycycline even low dose of 50 bid or erythromycin ointment as helpful.
Glue is poorly effective. Cryo and all of the like are also poorly effective. We used to do autologous blood injections, we rarely do it because they’re just not as effective as we would like. What you can do surgically though is you can try to convert a focal bleb to a diffuse bleb. Because if you can make a bleb more diffuse, it’s much less likely to leak and it’s more likely to heal leak. So, you can do a bleb needling, I will usually combine the bleb needling with a compression suture. So, here this person had especially it works well especially for leakage towards the edge of the bleb. So, this patient had a localized leak, I did a bleb needling, tried to make the bleb more diffuse as well as decompress the bleb, and then put a very tight suture here right across the side of leakage. You can eventually you may need to go back in and do a reoperation with a conjunctival flap or in some cases you may need even to use a conjunctival graft. That’s pretty rare though.
If you have bleb failure in the post-operative period, you can try digital massage, restart eyedrops, see where you wind up, check the pressure off the steroids, but then you may often need to try a needle revision. And I always try a needle revision before almost always before going to a trab or a tube and we’ve seen these photos before. Infection is associated with wound leak or thin/avascular blebs. Decrease risk if you use those antiseptic wipes, it’s good to try to treat those underlying conditions like lid infections, dacryocystitis, keep those lids clear. We definitely want to avoid inferior interpalpebral bleb, see how this either this little teeny localized bleb is, it’s really in the interpalpebral space.
If you get infection, we call it a blebitis if it’s in the bleb. So, an infection in the bleb is a serious problem but can usually be treated if caught early. So, we tell all our patients that had glaucoma filters that they need to call us, if they have a red eye they need to call us that day. They should never wait to see if it goes away. And when they call they need to tell the staff that they need to be seen that day, doctors’ orders. Because your staff as many times as you train them, there’s turnover, you know, they may not realize oh, red eye is probably conjunctivitis they can wait a couple of days. So, you have to tell – empower the patient to make sure that they say to the person at your office, my doctors told me I need to be seen today, my eye is red and I’ve had glaucoma surgery. And I actually have a contract that I have patients sign that tells them exactly what they need to do, who they need to call if it’s, you know, New Year’s Eve or Christmas Eve, you know how to make sure that they can get care that day.
So, in blebitis, if the infection is limited just to the bleb, there may be a small AC reaction, but there shouldn’t be a hypopyon. You can start with topical fluoroquinolones if the risk is low or if the blebitis is mild, and see them that later in the day. If the blebitis looks a little bit more severe and you want to use fortified topical drops and reevaluate again within hours. And it can have actually a good prognosis. But if it advances, you can get more of an AC reaction and then eventually a vitreal reaction and then it’s true endophthalmitis. And we need an intravitreal tap with injection of vancomycin and amikacin or other medications. Now, we sometimes do some cephalosporins. We use topical subconjunctival and systemic antibiotics and vitrectomy.
Yeah, you want to try everything in your power to avoid a blebitis turning into an endophthalmitis. What about bleb dysesthesia? This was more common in the past when you had these large elevated blebs that overhang the limbus and you want to try to alter the bleb profile. You can do a bleb needling and then put compression sutures down. So, just like that compression suture over the leak that I did in that other patient, you can put multiple sutures over these blebs and you want to treat it there’s a dellen at the limbus, you want to treat that dellen aggressively with lubrication and erythromycin if available erythromycin ointment at bed time.
We have going on here, oh this is just showing putting in a compression suture so you do a corneal bite and a bite high in the fornix and then you can tie that wound and it gives you a tight compression suture over the bleb. I sometimes like to crisscross them, but you can do them either way. So, in terms of assessing the postop filter, we want to look at the pressure, the anterior chamber, the anterior chamber depth. And we want to look at the bleb, we want to know common underlying conditions and beware of the flat bleb which is a risk of failure. Be very, very cautious when you see high pressure and a flat bleb with a shallow AC that’s where you have your most serious problems, your suprachoroidal hemorrhage, your aqueous misdirection. Be patient with shallow chambers and serous choroidals, they will often resolve but be more aggressive with hypotony maculopathy. But I don’t think we have to do those again.
So, let’s take a look at the questions. Let’s see where we are. So, there’re some concerns about not being able to get mitomycin since January, it was withdrawn due to safety problems. We’re using 5-FU, in some patients the tenons is too thick. I do think that’s a risk factor for encapsulated blebs. Now, you can inject mitomycin and you don’t have to do it as a pledget just as – you can inject mitomycin intraoperatively, you can also use a mitomycin pledget intraoperatively. So, we used to just get 5-FU postoperatively but we know now that you can inject it or use a large pledget intraoperatively and that may help. But yes, there is an increased risk of encapsulated blebs with 5-FU. But you can often get good filtration without mitomycin but I would suggest using it intraoperatively and getting a diffuse applications.
Years ago we used to see small localized blebs with the 5-FU, so you want to have a nice diffuse application. How to prevent post operative bleb leakage? Do you put in 8-0 vicryl suture in con? So, for the conjunctival closure for fornix-based conjunctival closure, I use nylon because it stays longer. You don’t have to especially if your patients are going to be going off and you may not be able to see them back as regularly as you would like. But I find a tough closure over the limbus with a small peritomy usually and there’s knots with a nylon usually hold that flat in place.
What happens if postop two weeks patient develops glaucoma secondary to steroids. So, at two weeks, you shouldn’t be having steroid glaucoma because you should have a working filter. And with a good working filter, the steroid shouldn’t be affecting that much at two weeks, I would loosen the stitches on the bleb. I would cut those, cut one stitch at a time until you try to develop filtration. And if you can think about earlier bleb needling, do you have a preferred taper schedule from immediate postop? So, with pred acetate, I generally use every two hours unless they’re high risk, then you can do every one hour. And then I usually keep them on every two hours for at least two weeks. And then they yeah, I do go to six times a day for a few weeks and four times a day for a few weeks. And it all is based on how they’re looking.
How many trab can we do? Well, we can probably get three and but I don’t recommend it. Because if a second one doesn’t work, I would try to get glaucoma drainage tube in place, or maybe even try a little cycle destruction. But I would definitely try bleb being aggressive with bled needling before moving on to a second trail. And even with the second trab, be aggressive with bleb needling before moving on. So, there’s a few things on trab.
Okay, what type of needle do you use for the conjunctival closure? I use not a spatulated needle, I use a taper, it’s a taper needle but it has a sharp tip. I can look up the numbers if you have similar companies that sell but it’s generally not a spatulated. It’s a taper needle but it has a sharp cutting tip. How do you deal with a tenon cyst formation postop? So, as we mentioned, you want aqueous suppression and steroids and you may need to revise but aqueous suppression and given a little bit of time because the pressures they may not ever be as good as they would have been without a tenon cyst but they may come to a level that is adequate. So, you with tenon cyst you actually want to restart medicines.
What is your, okay, what is your preferred follow-up schedule? So, I generally will see people on postop day one. And then if they look really excellent. I will wait a week. I used to always see them postop day three and that is a very legitimate time to do, one day postop then three or four days postop and then weekly for the first month. But you’re going to gauge it as how they look. If you find that you’re, if you can judge from the first post operative day that they’re looking fine and can go a week, you can go a week. But I usually get patients appointments, postop day ones and once a week for the first month and then every two weeks for the second month and then I gauge after that.
What do I think about MIGS, is trabs so your favorite among glaucoma surgeries? So, there’s a role for MIGS but it’s not for the same patients, who’re usually doing trabs on unless you’re talking about the XEN and the ForeSight might be. But for all the other makes they are usually for patients that are not as advanced. The nice thing is, is you could, you know, if someone is on the borderline, you could consider a MIGS like a gag procedure which can be very effective in semis. You can try that because you have not disturbed your conjunctival tissue at all. So, the nice thing about MIGS is you generally don’t lose a lot in terms of damaging the tissues you want for your trab.
We used to do canaloplasty ab externo, we used to use up so much real estate it just wasn’t worth it. But you can try the things. But usually the population for males is a little bit different than the population for trab. And one thing I like to keep in mind sometimes when I hear people talk about MIGS they say well, we can do this, we can do an eye stent and you can do a canaloplasty and you can repeat the canaloplasty and then do it with a, you know, you can do goniotomy procedure. Sometimes your patients don’t want to go back to the operating room once a year or every few months. They want it and they want to be done. And not to say that doing a trab is going to be risk free and it’s going to work every time, it’s not, it’s going to work back three quarters of the time if done well.
But sometimes it’s just more definitive and you can do it and in more cases your patients will be, you know, done or will have fewer trips to the operating room. Because a lot of people, you know, don’t want to spend their life just worrying, you know, going in and out of the operating room for another maintenance procedure for their glaucoma.
To whether there’s a – to decide between whether using a viscoelastic or an AC maintainer, which is your preference? I tend to use viscoelastic, just because I have it handy. It’s easy, but an AC maintainer is excellent. When I drain choroidals though I always use an interior chamber maintainer, because you want to really keep that eye pressurize the whole time if you’re ever draining choroidals. But for trabeculectomy, you can do either one. And some people for years, I didn’t use either, I would just do it quickly, I would have my preplay suture in my scleral flap, I’d lift the flap and go in and punch it slow it down quickly. And then we formed the chamber.
If the pain in the neck with using the viscoelastic is that you need to get it out of the eye after you saw that flap down. And you need to get it off the fields, you need to wash the outside of the eye and get it away because it’s incredibly important to check and assess the amount of flow you have during the surgery. And so, you need the viscoelastic gone, that’s the best way to make sure that you don’t have hypotony or high pressure is to really assess the amount of fluid flow you have intraoperatively and the viscoelastic has to go away.
Does ocular massage help after one or two weeks in case of high pressure? It can in some patients. I’ve had some patients go where I teach the massage and they go home and they’ve changed the course of their trabeculectomy. You have to be careful, you also hear horror stories sometimes the patients that were too exuberant, depressing, but yes, ocular massage in some cases can help even after one to two weeks.
Question was asking, do I need to put mitomycin under the flap? No, you don’t have to in fact, I don’t usually put it under the flap and in general I do injection. So, I don’t even use a pledget.
What is the ideal size of a sclerostomy – the sclerostomy under the flap? You wanted, it can be really small, it doesn’t take a big flap to have complete lack of resistance to outflow. So, you want it small and in the center and you want it to have the center so that there’s overlap between the underlying scleral bed and the flap. So, you don’t want to come into the edge of the flap, you just want a small central, so 1.5 mm maybe but you have a lot of leeway.
So, I think we talked a bit about 5-FU instead of mitomycin. So mitomycin, if you have a person at very high risk someone like an 85-year-old white person with blue eyes and thin conjunctival, you can try 5-FU instead of the mitomycin. We tend to still use mitomycin and just use very low dose maybe 0.05 mg per ml maybe 0.1 cc but you can consider 5-FU in those high risk cases for mitomycin.
What do I prefer limbus-based of fornix-based? The vast majority of a glaucoma uses fornix-based. And they can get beautiful blebs. If I have the opportunity as I mentioned to do limbus-based if I have a good scrub team with me, so good assistant and the eyes is enabled to a beautiful exposure with nice conch, not too thin, then, I love doing a limbus-based trab even though it’s more work in the operating room. I know I will never, I will not have a bleb leak.
Young patients have thick tenons, how do you handle it? Most of the time I just ignore it. I make my flap, when you make your conjunctival flap, when you’re doing the peritomy you have to be sure that you get through tenons insertions which is a millimeter to posterior to the limbus. So, you can do a very fine peritomy of the conjunctival but then you have to punch through the tenons and cut it. But once you do that, you don’t have to worry that much about your tenons. Some of it will retract. I’d still and only in rare instances do I cut out any tenons because you can usually get good flow and it protects you from having thin blebs. Different story with, you know, dealing with tenons when you’re dealing with XEN implants, you have to be really careful about your tenons in those cases.
What is the best surgery if trabeculectomy is not effective in a few years? I will again try bleb needling with aggressive bleb needling in the operating room with subconj mitomycin. You can try another trabeculectomy with higher dose mitomycin if you, and you then you can move on to a glaucoma drainage tube.
Let’s see, 17-year-old male TRAB with mitomycin bleb reformed times one is that, I wonder if that means AC chamber reformed. Now, shallow with diffuse bleb posteriorly both steps fail to control pressure and now back on acetazolamide and topical.
You know, I’m a little confused about that. Whether I guess the bleb is shallow, trab with mitomycin, the bleb is shallow and posteriorly but it is not working. I would try bleb needling on this patient, bleb needling. Dilute 2 mgs of mitomycin, oh here someone’s getting the recipe so we should look at it and then we can confirm. That would be 2 mgs of mitomycin and 10 mls of sterile water, use 0.05 mls, which will give you .1 mg and then you can dilute 0.05 mls to, yeah. So, I generally like to use a larger volume. So, you can take a larger volume of that and then dilute it with lidocaine. So, I’d like to use at least 0.1 mls to 0.2 mls to inject. So, I’d go with a little bit more and then dilute it with lidocaine.
How much time do you wait after injecting the mitomycin and opening the conjunctival? You don’t need very long. So, if I’m doing a combined with cataract, I will inject it on the field and do my cataract and then come back up. If I’m just doing trabeculectomy before I draped the patient, I will just go and inject the mitomycin, then they get prepped and draped. And then I come in and I start the surgery, so just in a few minutes.
Why had evoked a heart postop? You don’t want elevated episcleral venous pressure, so, when people bend over or upside down and indeed anyway, you have elevated episcleral venous pressure, which is not good for trabs and not good for bleeding risk.
Okay, I’ll keep going for another few minutes, they’re coming fast and furious. If trabeculectomy is done together with M6, would the incision be the same with the M6 incision? You can. You can do it at the same time. So, if you’re operating from a superior approach, I’ve seen some people do M6 temporarily. So, then you’d absolutely need a separate incision. But if you make your M6 superiorly you can cut, flaps in the center, you can even just cut one side, you can make a punch and you can cut one side and then make a punch and then show it down. And you just really be cautious about how you adjust the flow at that side, but you can use your M6 incision as a scleral tunnel and cut that at least. You don’t even have to cut both sides, you can just try to see if you get enough flow cutting one incision into the M6 scleral tunnel making a punch to one side of that and then seeing if you can get enough flow that way.
Is injection of mitomycin is effective as soft spun? I think it’s more effective and I think it’s better because I think it gives you a more diffuse application.
What is your approach to provide a fusion postop? I think we’ve covered that so, just briefly try to wade, treat with steroids, treat with cycloplegic, cut back on any aqueous suppressants and see if it’ll go away. And it can take a little while but most of the time they will go away. If it doesn’t, you’ll need to go in and drain it and consider putting sutures through the flat.
Do you do the peritomy immediately after mitomycin or wait some time? I think we covered that.
The AGM, I’m not sure what that is, with the AGM continued surgery, will titration of flow on table effect postop aqueous suppressant? I have a feeling that’s glaucoma medicines continue till surgery will take place and flow on the table effect postop aqueous suppressant. Yeah, it’s you will have an effect if you consider continued glaucoma medicines. But what you see on the table is really mechanical. And that’s what you want to say. So, you want to see the mechanical flow and then you may have a little bit of aqueous suppressant postop from the lingering effects of your topical medications. But you know that you gave the best mechanical flow and you know as those meds were off, it should be you’ll be in a much better position.
How could I make trabeculectomy more successful and long lasting and intractable you be at a glaucoma. One thing that’s very helpful is intracameral Kenalog. So, if you can get an intraocular steroid and depot steroid injection at the time of surgery, you’ll have a much better chance of long-term success. I don’t do this often. But if you have a very bad UV addict and you always also want to try to quiet the eye as much as possible with steroids. You can even do sub tenons right before the surgery but an intravitreal steroid injection would really, really be helpful.
How long do you steroid postops? Usually at least three months. It’s on a taper, but it’s three months. Sometimes, I will keep them on three times a week for long-term Monday, Wednesday, Friday, give them one drop of steroids just to keep it going. But most of the time we don’t.
Do you use posterior sclerotomy for prevention occurred or detachment? No, no. I don’t. I generally don’t do prophylactic posterior sclerotomy unless I have someone that I know is nanophthalmos. So, even when I do a Sturge-Weber, I don’t always do posterior sclerotomy but I just watch. I’m not sure how well they work after the first couple of days, but if I have nanophthalmos, yes, I would do a posterior sclerotomy prevent prophylactically.
What precautions should be taken to reduce wipe-out phenomenon? So, very often, the risk of wipe-out is much worse from not doing your surgery than doing your surgery. So, I’ve seen a lot of people with bad, you know, end-stage glaucoma at risk of losing central fixation and people will write in the chart, avoid surgery because of risk of wipe-out. But your wipe-out is much greater if your pressure is high and you don’t do the surgery than from the surgery. And there were some reports years ago that showed that loss of central vision was sometimes related to cystoid macular edema and not necessarily to progression to the glaucoma so that you could control that. But you just want to try to prevent wide variability of intraocular pressure postoperatively. So, you don’t want to have a high spike up and you don’t want to have dense high, you know, severe hypotony. So, as much as you can do to keep the pressure not fluctuating, that’s the best thing you can do for preventing wipe-out.
In your clinical practice, which technique is more safe and efficient? Well efficient and safe may be two different things. So, safe, they’re both safe and in my hands I still do like a limbus-based trab when I can do it, it just, I sleep well at night, I know that wound is not going to leak. The vast majority of fornix-based wounds don’t leak, but every now and again you’re going to have one that’s a pain in the neck. But fornix-based trab that’s what the peritomy is much more efficient to do. It is much easier to do. And as you’re learning trabeculectomy for those of you who are not doing trabeculectomy regularly, please start and do fornix-based trabs only for the first few years. Even fornix-based trabs are much easier to learn, much easier to do all the steps and especially if you don’t have an assistant.
Do you use antimetabolites in every case? Pretty much almost every case I use antimetabolites and I adjust the dosage depending on their risk factors.
How do you taper search? I think we did that how we handle there’s a complication like aqueous direction after trabeculectomy. So, as we talked about the risk, a lot of these questions I think came in before we talk – covered on the topics aqueous misdirection you start by treating conservatively with cycloplegia and aqueous suppressants, you can try to lays with the hyloid face but if you – if that doesn’t break the attack within a couple of days then you need to go in and create what a unicameral eye with the vitreous cyclectomy.
For digital pressure, would it be okay to be done infernally? Well absolutely. You know actually yes, you’re not going to deform the scleral flat bleb interface, but you’re going to increase the pressure and that can force fluid out of the eye. I don’t see a real great reason to do it. If I was not going to do it through the upper lid I would definitely do it straight ahead through the cornea just press straight back.
How many times do we need to do massage? That’s, you know, this is all just what you find works for you. I usually have patients pressed twice and I tell them it’s like ringing the doorbell, like, they press in, they press out. No rubbing, no massaging, no poking. Don’t hold that doorbell and just press in and out, in and out. And I usually have them do it twice a day, and depending on how much scarring they have, either I haven’t do the two presses twice a day or four times a day.
Would it be advisable to do trabeculectomy for uncontrolled glaucoma with tunnel vision or if other measures are better? Usually trabeculectomy is what you want to do in these cases. Because if they have just a small central eye lid left, you’re not going to play around with mix procedures. And you could do a non-valve – you could do a valve too that could work right away but you don’t want to do a non-valve too with the pressures high and you have, you know, advanced visual field loss to tunnel vision. But a trabeculectomy is an excellent, excellent procedure in that case. Post-trab vascularized bleb role of anti-VEGF. So, we’ve tried it and there’s lots of research that has looked at it and it doesn’t work great. I would just sort of let the eye heal a bit, quiet it down with some topical steroids and then I would go back in and do a bleb needling. So, anti-VEGF inhibitors, they can sometimes help a little bit but I’ve been underwhelmed and not really very excited about their use in vascularized blebs.
Do I start oral steroids for choroidal detachments? What really helped hypotony due to over filtration. I’m not a big fan of oral steroids. A lot of people do it. I don’t generally do it. I think the, you know, depending on the patient, the risk of the oral steroids could be worse than anything else. And there’s nothing that has proven that it helps. So, I will use topical steroids if I think that it’s coming from inflammation and aqueous shutdown. Sometimes we’ll cut back on topical steroids if you think it’s from over filtration.
Do you find trab alone has a better success rate than combined phaco-trab? What can you do to improve the flow post phaco-trab? So, yes, but it’s a little bit of a tradeoff. So, yes, the success rate for the trab is better than with the phaco-trab. But if you were thinking that you need to do a phaco-trab, you may need me to get that cataract out and if you do a trab by yourself, your cataract is probably going to worsen. So, while the trab alone has a better success rate than the phaco-trab, you’re probably going to have to go back in and do a phaco afterwards and then you can lose the effect of the trab. And sometimes you can lose it completely or lose some of the effectiveness. And then you have to go in and need all the bleb. Whereas, if you do a phaco-trab and you don’t get as good as success rate as you want, you can just go in and do the bleb. So, I look at it that phaco-trab, I can usually in almost every – when we done with a minimum with a maximum of two procedures whereas if I do the trab, then the phaco, then you still may need a third procedure. So, there’s a lot of people have a lot to say on the discussion of trab versus phaco-trab. I do quite a number of phaco-trab. Some people do no phaco-trab. So, that’s a very personal approach.
How successful is on African-American patients? So, African-American patients tend to have thick tenons, but with mitomycin, we had very good success rates.
What is different between localized bleb and encapsulated bleb? So, a localized bleb can be avascular and thin and leak, in fact, whereas an encapsulated bleb is often larger and it’s thick and dome shaped and usually is covered with angry vessels. It has no translucency at all. So, localized bleb can have, can just be localized, sometimes it has what’s called a ring of steel around it. It has a scar vent all around the outside. And so, if you ever go into either one of these blebs, you really needle in to try and break up that ring of steel around the bleb. An encapsulated bleb is just this giant dome of thick tissue.
How can we repair a large bleb? So, we show those compression sutures going over the bleb and sometimes it’s just too big and you just have to exercise it and do a conjunctival flap.
What is your experience with autologous blood injection for over-filtering trabs? I used to do it a lot, it doesn’t help. So, that’s what we learned. Sometimes it helps with wound leaks but it was never actually very good for over-filtering blebs.
For over filtration control with a large diameter contact lens, what protocol would you follow? So, you have to – one, be realistic. So, you may in the early postop period, having contact lens and a patch may help a little bit. It’s not going to turn around most likely a very hypotenuse over-filtering eye. But you can put the contact lens in and then just watch, you can give them a little bit of antibiotic while the contact lens is in and follow them within. So, it matters if it’s, for over filtration you can probably follow them in a week. If it’s for leaking bleb, you probably want to see them in a few days to a week at most. But you want to be in close contact with the patient, so the patient knows any sign of redness they need to call you right away.
So, we’ve gotten to the hour and a half point. And I know there’s still a lot of questions. You – I can work with all this and with Lawrence (phonetic) to try to answer some of these questions manually. But I think we’re going to need to stop now. But it has been a true privilege to have this chance to meet with you today. And never hesitate to reach out to me. I’m so happy to be able to chat with people so far and wide. So, please never hesitate to reach out. And I thank you so very much for being here today.