Lecture: Cataract Surgery in Eyes with Glaucoma

During this live webinar, various surgical topics are discussed including goniosynechialysis, minimally invasive glaucoma surgery and IOP lowering effects of standalone cataract surgery in eyes with glaucoma.

Lecturer: Dr. Malik Y. Kahook, Professor of Ophthalmology, University of Colorado Anschutz Medical Campus.


(To translate please select your language to the right of this page)

DR KAHOOK: Good morning, good afternoon, or good evening to everybody, depending on where you are in the world. All right, so the topic today is cataract surgery in eyes with glaucoma. My name is Malik Kahook, I’m professor of ophthalmology at the University of Colorado, and really happy to be on this conference today. Throughout this discussion, if you can write down some of your questions that might come up, you have the ability to share those questions, and we’ll get to them towards the end of the discussion here. I think it’s gonna be around 35 to 45 minutes or so, and then we’ll have some questions interspersed within the slides here, so we can get some participation that will hopefully allow us to share a little bit more, when it comes to what type of questions you might have. These are my financial disclosures. I work with several companies in ophthalmology. There’s really no direct relationship to many of the products that I’ll be discussing. One from New World Medical is one I work with closely, and I think that’ll be obvious when we get to it. The objectives today — we’ll be talking about MIGS, microinvasive glaucoma surgery, we’ll talk about cataract surgery for IOP lowering, I’ll talk a little bit about goniosynechialysis. Many of these patients can benefit from that procedure, and at the end we’ll talk about pearls for practice when we talk about combining glaucoma surgery with cataract surgery. I’ll start off with a case here. This is a 62-year-old male that I treat. Has a 12-year history of POAG treated bilaterally with Latanoprost and dorzolamide. Visual field deficit is stable over the last 3 or 4 years, visually significant cataract in both eyes, and the angles are open to the trabecular meshwork. He admits he forgets to use his dorzolamide a couple times a week, which means he’s probably not using it at all, and the question is: What is the next step? So we hear a lot about MIGS procedures, which means any surgical manipulation or device implantation, if I had a MIGS wish list, it would look like this. I would like to avoid a bleb at all costs. I would like something that’s like a trabeculectomy, but safer, easier to perform with less postoperative effort, and of course anything that could be cost effective for global care of glaucoma would be beneficial to all of us. So in my opinion, when you look at that wish list, cataract surgery is actually the best MIGS procedure we have. We use a small cornea-based incision, excellent safety, proven sustained IOP lowering, and all options remain on the table. I think part of the issue here is we’re seeing a paradigm shift in the way we think about treating glaucoma. Typically as glaucoma surgeons, we swing for the fences, try to get the best possible IOP lowering. Unfortunately that’s usually coupled with an increase in risk. So a trab and a glaucoma drainage device have been the traditional methods, but sometimes a lower risk procedure with maybe a little bit less IOP lowering is appropriate, similar to the MIGS or cataract extraction in the bottom left hand corner that you see here. One of the reasons I think we’re looking at this more and more, as far as MIGS or cataract surgery being an effective treatment is the fact that a lot of the trials looking at the MIGS devices reveal that cataract surgery alone has a tremendous amount of IOP lowering, so you see the bar graph on the right hand side. In the middle there, that’s the effect from cataract surgery alone, and then the coupled effect from a typical MIGS implant is really a small fraction of that. So you get a lot of IOP lowering, just from the cataract surgery alone. Now, the science of IOP lowering, when it comes to cataract surgery, is something that is evolving. We know that the level of IOP lowering after cataract surgery is probably due in some part to a remodeling of the trabecular meshwork, probably linked to something called e-selectin or IL-1. You see this in laser trabeculoplasty. There’s a remodeling that happens with the effort of doing cataract surgery and the flow of fluid around the eye. We routinely see significant IOP lowering, even when the preoperative angles are wide open. And this is important. We don’t have to have deepening of the chamber in order to get IOP lowering. Having said that, a lot of people have spent a great deal of effort trying to elucidate the mechanisms for IOP lowering. This is a study looking at e-selectin or change in the cytokine levels within the anterior chamber and what might happen to the trabecular meshwork. It’s a little bit of a busy slide, but basically what you see here is that after the introduction of ultrasound into a medium, healthy or glaucomatous trabecular meshwork, you see a change in the cytokine level within the fluid that could lead to a remodeling of the extracellular matrix, which then enhances the outflow of fluid from the eye and decreases intraocular pressure. There have been a great deal of studies also looking at the angle anatomy. And we know that the level of IOP lowering after cataract surgery is proportional to the widening of the angle, and that might seem to differ from what I said about wide open angles having a decrease in intraocular pressure, and that indicates the work we have left. We have to differentiate between angle opening versus wide open angles that also decrease the pressure. It’s probably multifactorial, and we’re just trying to tease out the differences. We know that lens vaults may be predictive of IOP lowering, and there are things being studied through gonioscopy and anterior segment OCT, characteristics of the iris, how thick the iris might be peripherally versus centrally, and the lens vault. There are studies ongoing to tease out the exact differences in lens vault in patients who might decrease IOP versus those who don’t. We know that doing cataract surgery alone in patients who have chronic angle closure who have anterior synechiae is not as effective. One pearl, because we’re talking about cataract surgery in glaucoma, if you have a patient who requires an LPI and you know this patient will be going for cataract surgery, which is the overwhelming majority of these patients, try and put the hole in the iris right beneath where you plan putting your incision for cataract surgery. And the reason for that is you will have less likelihood of the iris coming into the wound at the time of cataract surgery if there’s an LPI right beneath that cataract incision. So the science of IOP lowering, you can tell, is pretty complex and still being studied. ECM remodeling and change in angle configuration are both relevant to the mechanism of IOP lowering, and studies are underway with advanced imaging request being advanced imaging, as well as protein sampling, to understand the process. What about acute angle closure? This is a topic we hear a lot about in glaucoma circles, and it has a similar conclusion, that phaco is a good option. Dr. Lam studied this and found that phaco had lower IOP, less medication, and better acuity compared to the standard of doing a peripheral laser iridotomy. You can see here the table the comparison with the present study, this is the Lam study showing that the prevalence of IOP rise at different follow-up time points is very favorable for cataract surgery versus various medications and LPI. This was from the EAGLE trial, and we’re just now starting to understand some results from the EAGLE trial. This is something I’m still digging into, trying to figure it out. The study itself looked at the best approach to treating primary angle closure glaucoma with standard of care, which is LPI, versus lens extraction. Patient 50 or over, pressure 30 or higher. 419 patients, 208 assigned to lens extraction and 211 to standard of care. Pressure was 1.18 millimeters lower in the lens extraction, versus the standard of care. The conclusion here is that lens extraction showed greater efficacy, marginal — if you look at the exact number — but was more cost effective than doing standard of care and should be considered as first line therapy. This is something, again, that we’re still trying to tease out the details. But it’s good to see that cataract surgery alone can be quite effective, and also cost effective. Chronic angle closure. A little bit of a different story here when it comes to chronic angle closure. A study in 2008 looked at medically controlled chronic angle closure and so no difference in IOP after three months. Phaco-trab was on less medications but had more complications. In 2009, the same group looked at medically uncontrolled CACG. Phaco alone lowered intraocular pressure by 8 millimeters of mercury. On the other hand, phaco-trab lowered IOP 13.6 versus 15.9. Mean of 1.25 less drops but it had more complications and more progression of the optic neuropathy. So there are a lot of inconsistencies here. I’ll talk more about this when I talk about goniosynechialysis. This was a study looking at cataract patients in the OHTS trial. Looking at the preoperative IOP, which was defined as the IOP of up to three visits prior to the split date, and what happened to the IOP after the split date. If you’re not familiar with it, it essentially looks like this, where you have intraocular pressures to the left of the zero, showing what the pressures were before cataract surgery, and to the right side of the zero, you see the cataract surgery. There’s a big dip in intraocular pressure, versus the control, which remained fairly steady, and the conclusion is that the mean decrease in IOP was 4 millimeters of mercury, quite significant in this group. And the control group had almost no decrease in pressure. 0.3 during that follow-up. Just to dig into the numbers a little bit more, this is one fact that has influenced my care of these patients. A significant number of these patients — about 40% of these patients — had a decrease of intraocular pressure greater than 20%. So that is a significant number that I think can help patients, and I typically put this as part of my surgical care of patients who come in with ocular hypertension who are high risk for advancing to glaucoma. On the other hand, I do want to highlight this last line, that there was an 11% increase in intraocular pressure? So just 7 eyes in this case, but it’s something that you have to keep your eyes on. That not every patient has a decrease in pressure and in fact some patients might have a slight increase in pressure that might be significant for that patient and requires follow-up. When I first started thinking about cataract surgery for IOP lowering, these papers were starting to come out from Poley and colleagues, out of Minnesota. And you can see here in eyes with high pressure, ocular hypertensives, or normotensive patients there was a significant decrease in pressure that correlated with the starting pressure. If you had a pressure around 31, there was a high likelihood you would decrease your pressure by about 27%. And the effect decreased as the pressure decreased from the preoperative levels that you see on the left hand side. This is not earth shattering, because we know there’s a decrease in pressure that correlated with the starting pressure. However, this was one of the first studies to look at decrease in pressure after cataract surgery alone. We took this a step further, just looking at glaucomatous eyes with this table here, and you see that there’s a similar effect. The glaucomatous eyes had a significant decrease in intraocular pressure that correlated with the preoperative pressure. In this case, up to a 34% decrease in preoperative pressure. Compared to the preoperative pressure in patients who had a pressure between 23 and 29. In addition to that, the mean number of glaucoma drops was 1.3 before surgery and 1.0 at the final measurement. So there was, if anything, a slight decrease in the use of medications, along with this robust IOP lowering, and I think that also pushes me towards doing cataract surgery earlier in my patients who have glaucoma, particularly those who are having a pressure check where you’re getting above the 22 millimeters of mercury level. So we’re gonna go to the first question, and Lawrence is gonna take over here, while I read this question. Which mechanism has been linked with IOP lowering in glaucoma eyes postcataract extraction? Trabecular meshwork with ECM changes related to ultrasound, degree of lens vault preoperatively, both A and B, or none of the above. We’ll see if we can get the results put up here by Lawrence in a little bit. So we have 58% saying both A and B, and that is the right answer, so I’m gonna advance the slides here, and just highlight that. We covered in the first few slides that there are two mechanisms being studied extensively. One is the change in the extracellular matrix from cytokines due to ultrasound, and also the lens vault preoperatively, and how that might correlate with pressure reduction after surgery. So stay tuned. We’re gonna learn more about this as time goes by. It seems like cataract surgery would be an awful control group if you’re studying the effects of a glaucoma procedure at the same time as cataract surgery. What I mean by that is: If you’re looking at cataract surgery with a MIGS device and your control group is cataract surgery alone, we’ve seen cataract surgery alone has a robust IOP lowering effect, so that might cloud how we envision the use of a glaucoma device along with cataract surgery. And we’re starting to learn a lot from the various MIGS trials that have come out. And one of the first studies that was pretty robust was by Glaukos, looking at the iStent device. Glaukos is an innovator with the MIGS devices, and these devices have been analyzed from left to right. What we see is that the IOP less than 21 millimeters of mercury without medications was robust in the iStent group, but if you look at the phaco group, you can see there’s a robust effect from phaco alone. The question is: When do you have to combine the MIGS device with phaco if phaco alone is quite robust? You see the same thing with medication reduction. Still very robust with both phaco and phaco plus. Follow-up studies to this with other devices — in this case, a suprachoroidal device, the CyPass. This was the major study, the COMPASS trial, which showed very similar to the iStent — the control group, which was phaco alone, was robust in IOP lowering. Very robust study looking at a tremendous amount of patients. 131 in the control, 374 in the phaco plus CyPass, and it shows, I think, quite definitively that phaco alone does a very good job, and you do get an extra effect with CyPass just like you did with the iStent. A third device is the Hydrus device, which fits into Schlemm’s canal. This is getting into a place where you’re targeting a few more collector channels with one treatment. And you see that the robust number of patients that were treated showed a very similar effect to the other two studies, as far as the cataract surgery patients, showing a robust IOP lowering, both at 12 months and at 24 months, although you see the trend starting to wane a little bit at 24 months. This is still statistically significant, and quite robust from the baseline of around 26 or so, going down to around 19. This makes me feel very good about offering cataract surgery as a standalone procedure for many of my glaucoma patients, although I do keep in mind that the device implantations here that you’re seeing do give me a little bit more IOP lowering. So a note of caution. We’re talking about the positives here but the Poley and colleagues paper helped us understand another aspect to this. 55% of patients had lower IOP, 30% had higher IOP, and 15% had no change. So 55% of patients had a higher IOP in these cases, so while you do get robust IOP lowering in many cases, in some instances you might get an elevation in pressure. In most cases not very significant, but you should pay attention to it. In some cases, elevation in pressure after standalone cataract surgery can be significant. Especially in these trials where the IOP may increase by 2 millimeters of mercury on average. You might have to increase medication or do something else to decrease the pressure after surgery. Keep this in mind when you’re treating patients. So back to the case report we’re starting out with. What is your next step? I don’t think it’ll come as any surprise to see that the thing we did in this case was cataract surgery alone. The pressure decreased to 14 millimeters of mercury in both eyes, and the patient was off of all medications, which he probably wasn’t taking to begin with. So we were able to achieve our goal pressure and get the patient off of medications that he probably wasn’t adherent to anyway. So what is my practice pattern? In glaucoma suspects in ocular hypertensives, I choose to do phaco alone when they have visually significant cataract. In glaucoma with controlled IOP on 1 to 3 medications, I do phaco plus with the goal of getting the patient off of one or more of their medications. Glaucoma with uncontrolled IOP on one to three meds, I still do phaco plus, a minimally invasive procedure combined with phaco, in order to avoid the trabs and tubes that have a higher degree of complications. I also try not to combine cataract surgery with trabs or with tubes, because I think those patients tend to do a little bit worse with an elevation in their intraocular pressure, due to inflammation that happens with combined surgery. That’s my basic practice pattern that I live by. What does evidence-based medicine teach us? Just looking at the science that has been published, I think we can say that phaco alone is a viable surgical option for narrow angle glaucoma. Phaco alone is also a viable option for controlled glaucoma on one to three medications. In uncontrolled glaucoma, I think we can say that the evidence-based medicine is still evolving. The patient and the surgeon should discuss what’s possible and consider phaco plus or sequential surgery. Is it possible to do a phaco plus a minimally invasive device, or can we do phaco first followed by trab and tube later on or cataract first followed by trab and tube later on? In many cases, the art of medicine matters just as much as the science, and that’s something that I think we all recognize. That the more we practice, the more we understand that there’s a lot of art to what we do. I briefly want to touch on goniosynechialysis. Who is a candidate? Patients with primary angle closure glaucoma. That’s an easy decision. CACG with elevated IOP and at least 50% of the angle sealed is a good candidate. Many have advocated for fresh treatment. This is a patient that might have PAS that’s less than 6 months old, and not much longer than that. That’s controversial. I have treated patients with PAS that has been longstanding and still seen an effect from that. Stand alone GSL might have IOP benefits, but this is controversial and dependent on timing. It depends on which paper you read or what your particular experience might be. Who is not a candidate? Eyes with advanced cupping and central visual field defects. Caution in patients on anticoagulant and antiplatelet therapy. There might be more of a tendency to have a reflux in heme. So just exercise caution in those cases. This is what the procedure looks like, and one thing I would like to emphasize here when it comes to GSL. If you don’t remember anything else from the technique standpoint, remember that you should pull down and not centrally. So you’re basically teasing off the iris from the trabecular meshwork, and you’re pulling down in order to do that. If you pull centrally, you might run into problems with a tear in the iris root. And so pulling down is a little bit more gentle, and also achieves the end result of teasing off the trabecular meshwork better. Potential complications, as I mentioned before, hyphema, especially patients who might be on blood thinners. Chronic inflammation, minimize tugging on the iris. Make sure you’re pulling down gently and not centrally, and you could get iridodialysis which could lead to hypotony. It’s rare, and proper technique could help you avoid that. Who is a candidate for GSL? Only pseudophakic patients? Only phakic patients? Chronic angle closure glaucoma with over 50% PAS, or none of the above? We’ll wait here to see what the percentages look like. All right. 85% chose the right answer. In this case, CACG with 50% PAS. In only pseudophakic or only phakic — we can treat both. It’s not relegated to one or the other. That’s why the choice is C. There are MIGS devices that can be used. This is just a small portion of the different devices. I do want to talk a little bit about the evolution of how we’re looking at MIGS from a training standpoint. This is very similar to the definition that I posed earlier in the talk. This is the definition by Ike Ahmed. Essentially what MIGS is offering is a decrease in intraocular pressure with a follow-up that’s very similar to cataract surgery alone. When combining with cataract surgery, I always consent the patients for plus or minus. The glaucoma procedure — sometimes you do the cataract surgery and you just can’t complete the glaucoma part of the procedure, so it’s always good to have that conversation with the patient beforehand. I discuss that the recovery may be a little bit different from cataract surgery, where you might have to use steroids a little bit longer. Dilation and preoperative drops are typical, and I discuss positioning prior to the case. You have to rotate the head 45 degrees, rotate the microscope 45 degrees, and it’s good to have the patient realize that before going in, because they’ll sense the commotion when the nurses are helping with the microscope or helping reposition the head, and preparing that goes a long way. Standalone — antibiotic plus pilocarpine is the only difference. We add it to constrict the pupil. Otherwise, as above. Intraoperative — use miotics so you can get a better view of the trabecular meshwork. It’s not necessary, but I find it helpful. Find routine cases with cooperative patients. Consider peribulbar anesthetic. We typically do all MIGS procedures with topical anesthesia, but you might consider peribulbar for your first case, because it might take you a little bit longer to complete. Hydrate the wounds well, and make sure there’s no hypotony that could cause blood to reflux back into the eye. A little bit different than cataract surgery alone, as far as positioning your elbows, instead of just being at the sides, as you typically do with cataract surgery. In this case, you have one hand, one arm that’s extended. In the case of cornea, the incisions are typically what you’re operating in. In cataract surgery, you’re going through both incisions, as opposed to with MIGS you have one hand on top and one hand inside the eye, because you’re holding the gonial lens. Bimanual for cataract surgery, but the movements in a MIGS procedure should be practiced beforehand, because it feels a little bit different. And the operative space. You’re working above or below the iris in cataract surgery, and this is what it looks like. Right hand side, you’re doing a combined procedure, using a gonial lens. The ergonomics are different, and it’s something you want to be comfortable with, before your first procedures. Gonioscopy. Place viscoelastic on the lens rather than on the eye. Rest the hand on the forehead or the zygoma, depending on which eye you’re operating on. Don’t use the lens to direct the eye. There’s a tendency for the surgeon to direct the eye while using the gonial lens, and that causes stria on the cornea. Have the patient positioned correctly and ask them to look the right way. And then zoom in. That’s the picture on the upper right hand side. You basically want to see either side of the gonial lens, and that gives you the proper magnification of the trabecular meshwork. This is one of my colleagues here in the US, John Berdahl, showing a practice session before doing your first MIGS procedures. So what he’s doing here is he’s going in with his chopper and he’s positioned the patient after standard cataract surgery, and he’s just practicing the motion, the right to left hand side sweep that you do with many of these procedures. And that gives you an idea of what you might expect when you’re first doing your first procedures. Wound construction is really important. You want to make sure that you’re not touching any of the perilimbal vessels. If you have any oozing during the procedure, when you’re doing a MIGS procedure, you might get some of the blood into the viscoelastic, which can obscure your view. And give yourself some room. I say a 2.4 millimeter is good for the first cases to make sure you don’t get oar locking in the wound. That you have enough space to move right to left. This is putting it all together. You’re gonna see a goniotomy procedure. This is a device I had a hand in developing. With New World Medical. It’s basically a device that goes in and strips the trabecular meshwork. You see a movement from left to right, followed by repositioning to the right hand side and moving right to left. And you can see stable movement, good view, and what you’re getting here is a decrease in intraocular pressure by removing the trabecular meshwork entirely. And then you just go in with your Duet forceps or any type of capsulorrhexis forceps and remove that trabecular meshwork. At the conclusion of the case we like to do this fluid wave, the blanching of the vessels when you inject BSS into the eye, and that just indicates that you were successfully able to bypass the trabecular meshwork. This is the strip of trabecular meshwork you get at the end, which we’ve been having a lot of fun analyzing the different specimens, looking at what the process of glaucoma looks like and what trabecular meshwork can do in these cases, as far as looking at the effect of medication, different surgical procedures — starting to publish a lot on this tissue bank that we’ve developed. Postoperatively, similar to cataract surgery alone. The drops are similar, with antibiotics, steroids, NSAIDs in some cases, some surgeons choose to use pilocarpine to keep the angle open longer, but you don’t necessarily have to do that. One thing that is important, though, is to watch out for steroid response glaucoma. Even if you remove the trabecular meshwork, these patients can get an increase in IOP with steroids, so I like to keep the patients on at least one glaucoma medication while they’re on their steroid therapy to avoid some of those spikes that we can see. So last question here: Which statement is true? Glaucomatous eyes can still experience steroid response IOP elevation, MIGS approaches lead to more rigorous postoperative follow-up compared to CE alone, MIGS approaches rarely lead to decrease in IOP lowering medications, all of the above. Waiting for the response here. All right. All of the above was the answer that we have, so I’m gonna move to the answer slide. The answer is: Glaucomatous eyes can still experience IOP elevation. MIGS approaches lead to more rigorous follow-up — that’s often not the case. It’s typically similar to cataract surgery alone. MIGS approaches rarely lead to decrease — that’s why we’re doing it, because it does lead to IOP decrease. So the proper answer here is A. So summary. Standalone cataract surgery is an excellent IOP lowering procedure. Narrow angles in some but not all circumstances benefit from early CE. GSL is an important skill to master. MIGS procedures require diligent practice. We have to do the practice before we do the procedure so we get comfortable with positioning. And learning specific angle-based surgery is important. Learn how to do it before going into your first cases. And I always like to close with the statement: We continue to learn from each other. This is really important. I’ve visited operating rooms all around the world. We each have our pearls and nuances and I’m happy to share with you some of mine, and hopefully can learn from you throughout the question and answer session. Thank you very much.

>> Thank you, Dr. Kahook. There’s no questions yet. I’m just gonna share my screen. Because there were a bunch of questions that were asked at the time of registration. Since we have some time, do you mind going through a couple of these?

DR KAHOOK: Sure, yeah. Do you have any specific cataract surgery in eyes with glaucoma questions? That’s my question. So can cataract surgery alone reduce the intraocular pressure? We definitely went through that in the first few slides. You can see a robust pressure lowering in patients, especially those who start off with a very high intraocular pressure. Above that 22 millimeters of mercury, typically above 25 millimeters of mercury. Those patients can see a robust IOP lowering. And keep in mind some of these patients might have an elevation in pressure, so follow-up is really important. Can mitomycin-c be used in combined surgery? Absolutely. So we use mitomycin-c combined with some of the MIGS plus procedures, an implantation of a stent that drains fluid from the inside to the outside of the eye. In this case we inject the mitomycin into the Tenon’s capsule, rather than open up the conj and put it on the sclera, more and more what we’re doing for both our trabs as well as the ab interno procedures, is we’re injecting the mitomycin in very small doses, injecting it posteriorly so we can get flow posteriorly, away from the limbus, and we’re finding it to be quite successful. It also streamlines things in the operating room, where we’re able to not take as much time for the mitomycin, to apply it and wash it away. Decision making between phaco-trab versus phaco. I have a huge bias I’ll admit to. I don’t like combining glaucoma surgery with phaco. I’ve found over the last 14 years of practice that doing standalone phaco or trab ends up a much better result for the patient. And typically I’ll do the phaco first, see what kind of IOP lowering I get, which can sometimes be surprising and quite robust, and that can influence what kind of glaucoma procedure I do, whether it’s a trab or endocyclophotocoagulation, I might do surgery in the trabecular meshwork or suprachoroidal space. That can help the patient get a less invasive glaucoma procedure down the line. And I typically combine the focus and I typically combine the phaco with a minimally invasive procedure. A lot of high pressure glaucoma do surprisingly well with phaco plus a minimally invasive option. For what period pre- and postoperatively would you recommend suspension of prostaglandin inhibitors? Another great question here. I don’t stop my prostaglandin drugs. So Xalatan, Travatan, the trade names we use in the US — there was a lot of thought in the past that this might increase the rate of cystoid macular edema postcataract surgery. I only stop those in patients with a history of inflammatory diseases, in which case I don’t typically have them on those drops to begin with. But I don’t change my routine for prostaglandin analogs at the time of surgery, and I think there’s plenty of information to corroborate the fact that you don’t need to do that, including the history of thousands of patients here at the University of Colorado, where we didn’t find a link between the use of prostaglandins and the rate of CME after surgery. How do you approach the surgery? I think I answered that with number four. How to do combined surgery phaco and trab? Again, a little bit of a bias here on my part. I don’t combine the two. Certainly you can do same incision for cataract surgery where you lift up a flap and do cataract surgery from that flap and follow up with a trab out of that same wound. More typically surgeons who are combining the two have separate incisions where they do clear cornea for the phaco followed by trabeculectomy, and I think you can do whatever you’re most comfortable with. Is it possible to perform trabeculectomy after routine 12 o’clock SICS? Absolutely. You might still run into… If you’re doing a postoperative follow-up in a patient who had SICS surgery and ended up needing to do trabeculectomy, you might run into more scarring in this case and might need more diligence as far as wound construction and closure of your conjunctiva. For combined surgery, just refer back to my last answer. There are different ways to do that, depending on your preference. Precautions while operating on a post-transaction or with superior bleb? Precautions while operating? In this case I think if you have a superior bleb, the most important thing is just avoid any sharp instrumentation — particularly the Thornton ring, which a lot of us use to stabilize the eye during cataract surgery. That has significantly sharpened teeth on the bottom, that can penetrate a superior bleb. So we tend to go a little bit more temporally in these cases to stay away from the superior bleb. One thing I will add here is, if you’re doing cataract surgery on a patient who does have a bleb, it might help to needle or tease away some of the scar tissue in that bleb at the end of the case. A very elegant way to do that is to get a cyclodialysis spatula, fit it in through the clear corneal incision you use for the cataract surgery, and bring the distal end of that cyclodialysis spatula through the sclerotomy, work your way into the bleb, and you can lift up the scar tissue from an ab interno approach to lift up on the Tenon’s capsule that might be scarred down. That’s one thing you can do to decrease the chances of that superior bleb scarring at the end of cataract surgery, which unfortunately can happen at times, when you raise some of the inflammation. That can happen after cataract surgery. Could influence your bleb. So doing that procedure with the cyclodialysis spatula will increase flow and potentially allow that blood to survive much longer. What could be the approach in a patient who has a wide excavation of the optic disc? And obviously, with glaucoma… What could be the approach in a patient? So basically the way that I understand this question is: What do you do for patients with advanced glaucoma when it comes to combining with cataract surgery? This is not a straightforward question. It depends on your comfort level with the amount of MIGS procedures that you’ve done. It is rare for me not to consider doing glaucoma surgery combined with one or two minimally invasive procedures, before I go to a trab and a tube. No matter what their disease status is. Now, if a patient has split fixation, I’m worried about them worsening because they have a 0.99 cup and their target pressure is 12 and they’re starting out with a 25, in those patients, I certainly go to a trab or a tube standalone, but in patients who have elevated intraocular pressure, they’re going through cataract surgery, typically I’ll do a MIGS procedure, sometimes combined with endocyclophotocoagulation, at the same time doing an outflow procedure like an iStent, Hydrus, CyPass, or goniotomy. In this case, you can get very robust IOP lowering with a cataract surgery, even in patients with an optic disc that is advanced, as far as glaucomatous optic neuropathy. So it really is the art of medicine here. What are you comfortable with? What do you see in your own hands, and how much do you want to stay away from a bleb when it comes to a trab or a tube? I want to do everything possible to avoid a bleb, if at all possible. What is your experience on intraocular pressure reduction after cataract surgery in pseudoexfoliation glaucoma? These patients tend to do very well early on in the process, because you’ve washed away what’s plugging the trabecular meshwork. Unfortunately, these patients tend to have a rise, because the pseudoexfoliation process does not stop after cataract extraction, and you can see a rise in the intraocular pressure that happens over time, and you have to go back and do something more definitive in these patients. We certainly start out with cataract surgery alone and try to push glaucoma surgery whenever possible. They often do well with a goniotomy to get as much flow as possible without plugging the trabecular meshwork. When performing phaco-trab, is it better to use AC maintainer or Healon? I’ve done plenty of these with any viscoelastic, not just Healon. I find the chamber is much more stable with a viscoelastic in the eye, rather than an AC maintainer. There are cost issues, access to different viscoelastics, and in that case, AC maintainers are adequate, but you can get fluctuation that predisposes you to bleeding or even hemorrhages. When should we consider cataract surgery alone in patients with cataract and glaucoma R-F glaucoma? I think we’ve answered that extensively. There are many cases where cataract surgery combined with glaucoma surgery makes a lot of sense, but you’ve seen data that even patients with high pressure can do well with cataract surgery alone. So a lot of this is: What’s the status of the optic nerve? If it’s early disease, cataract surgery alone and watching how the patient reacts is very appropriate. If the glaucoma is moderate to severe, going in with cataract plus a glaucoma procedure in many cases — a MIGS procedure, combined with an inflow procedure, like an endocyclophotocoagulation, would be the way to go. A lot of this is nuanced. Depends on the patient, what the disease status is, and how many medications they might be on. This final question: What anesthesia is best for eyes with glaucoma? I would want topical therapy for almost all procedures, except tube implantation. I’ve found that patients with trabs or any of the MIGS procedures do very well with topical therapy. In the case of trabs, we can augment with a sub-Tenon’s injection of lidocaine and bupivacaine. Peribulbar and retrobulbar anesthetic in my opinion has been the most comfortable for patients, giving them hours of relief to make them comfortable. Topical anesthesia is my go-to, and rarely do I use a retrobulbar in anything other than a glaucoma drainage device, to give the patients comfort and me comfort during the procedure, so the eye isn’t moving and I don’t feel like any type of manipulation is causing discomfort for the patient. Any other questions come through?

>> Looks like one question came through live, if you want to open that up.

DR KAHOOK: Sure. There it goes. From anonymous attendee. How about in remote areas where there are no glaucoma specialists? Do you advise general ophthalmologists to do this? The question is… What the word “this” means. I think that any ophthalmologist who is getting training and practicing in MIGS procedures or angle procedures can do any of the procedures that I just talked about. Cataract surgery itself, if the general ophthalmologist is performing that, which I assume they would be in this case, then they can do iStent, they can do goniotomy, they can do any type of laser procedure, if they have access to it. In cases of remote surgery, a lot of times expense is an issue, of course, and that’s the case certainly in many places around the US and around the world. I try to go to less of the implant procedures, because in many circumstances, they’re cost-prohibitive. So a goniotomy procedure I think is very much achievable. For the general ophthalmologist. If you can do a capsulorrhexis, you can certainly do a goniotomy. So I would look… I would tailor the therapies to the certain specific environment that I’m in. From a postoperative standpoint, you’re not really adding a lot of postoperative rigor, so if you’re in a remote area where people are traveling in for the surgery and they have to travel back where the care may be less skilled, I think doing these procedures is the way to go compared to a trab or a tube, because you can essentially do what you’re doing for cataract surgery alone and the patient tends to do very well. So that’s how I would do it. The MIGS and ab interno procedures lend themselves well to general ophthalmologists in remote areas, especially in cases where you’re not tagged to any type of electricity or implant that might be cost-prohibitive. There may be a number of options in specific geographic areas.

>> So let’s wait about 30 seconds and see if any more questions come in. If not, we can probably end there.

DR KAHOOK: Okay, sounds good.

>> All right. So it looks like that’s all the questions. So thank you, Dr. Kahook, for your time.

DR KAHOOK: Thanks, everybody, for listening. Thank you, Lawrence.

Download Slides


May 17, 2018

Last Updated: October 31, 2022

Leave a Comment