In this presentation, Dr. Wallace Alward explains the causes, pathophysiology, epidemiology and risk factors of angle closure glaucoma. He presents cases and gonioscopy videos to explain more about AGC. He explains the differential diagnosis and treatment options. It also has a question and answer session at the end of the presentation.
Lecturer: Dr. Wallace Alward
DR ALWARD: So I’m gonna talk about angle closure glaucoma, which we see more here than we see in Iowa. So pupillary block is caused when the iris comes up over the trabecular meshwork. I think that’s kind of obvious. And it can cause an abrupt elevation in intraocular pressure that can cause pain, if it’s an acute attack. But there are also kinds of pupillary block that are intermittent and chronic. So in pupillary block, there are some other theories, but mostly we think that there is a relative seal between the lens and the iris that traps aqueous and pushes aqueous forward. So I think about this as being different from open-angle glaucoma, in that open-angle glaucoma is like when the sink — the drain in your sink slowly stops working. Gradual onset. Gets a little bit worse at a time. But in angle closure, it’s like you put the plug in the drain. It stops working all of a sudden. So the things that contribute — number one — one of them is race. So as you all know, it’s more prevalent in Asians. And I think a really stunning statistic is that in China, angle closure glaucoma causes 90% of blindness. And it seems that it’s a somewhat different disease that responds less well to iridotomy than Caucasian eyes respond to iridotomy. So another risk factor is hyperopia. A small eye, shallow anterior chamber. Older age, because as we get older, our lens is the only part of us that keeps growing. Women are more likely to get acute angle closure glaucoma than men. I don’t know why. And family history is very important. So if you see a patient who has pupillary block angle closure glaucoma, you should tell them that their brothers and sisters need to be examined. Because their risk is as high as 35% that they too will develop this disease. So we know that screening for glaucoma in general is not — does not produce high results. But screening this population would be very, very important. So things that contribute would be being in a dim room, because the pupil dilates. And basically anything that will dilate the eye, like stress. Or some medicines can dilate the eye a little bit. So in the US, all these medicines, antidepressants and cold medicines, will say “Don’t use this if you have glaucoma.” But these are totally worthless, because people who have narrow angles should have already had an iridotomy. So it really only applies to people who don’t know they’re at risk. It’s kind of stupid. And it’s important that people don’t go into pupillary block when they’re completely dilated. They don’t usually go into pupillary block when they’re completely dilated, because the iris is not touching the lens. So what will sometimes happen is you have somebody who you’re worried about. You dilate them. And then you check their pressure when they’re dilated. But that’s not that helpful. So what happens is the eye dilates quickly, but it comes down slowly. And so they develop pupillary block after they leave the office, when they’re on the bus going home. As the pupil comes down to mid-position. So it’s not in maximum dilation. It’s in mid-dilation. So if you dilate someone in the clinic and you check them when they’re fully dilated, their pressure doesn’t go up. But when the pupil is slowly coming down, that’s when they go into angle closure, after they’re done in your office. We have a lot of interpreters. It’s good. So the other thing is — if you give somebody very strong cholinergics, like pilocarpine, that moves the lens-iris diaphragm forward, and that can cause pupillary block. So, again, there’s three forms. We mostly think about acute, but intermittent — at least where I live — is really important. And you can have chronic pupillary block that acts like primary open-angle glaucoma. So acute you all know. They have eye pain that can be very severe. Headache. Blurred vision. Colored halos around lights, and can have nausea and vomiting. So this is just a case. 49-year-old man presents with acute loss of vision and pain in his right eye. He has a four-day history of right-sided headache. Gradually got worse. So on the day we saw him, his pain was constant. He had nausea. He had no history of trauma. So this is what you would expect to see in somebody with acute pupillary block angle closure. The pupil is mid-dilated. And the cornea is cloudy. Steamy. And I think I asked this yesterday. So let’s see if you were paying attention. So you should ask yourself two questions: What is the refractive error? They should be hyperopic. If they’re a -4 myope, they probably don’t have pupillary block. And you should also ask: What does the other angle look like? You can’t do gonioscopy on this eye, but you could do gonioscopy on the other eye. That’s way more than I said. Good. What is the refractive error? We already said that. What does the other angle look like? So he’s count-fingers in the right eye, pressure of 50 millimeters of mercury, he has a hyperopic refraction. And we already described all of this. So he has iris bombe. The iris is bowed forward. Just another picture of iris bombe. So sometimes people will have an attack of angle closure, and then it will break on its own. And then they might present with an eye that has inflammation and low pressure. And then, if you see somebody after an attack, there are some signs that they had an attack before. So I will show you all of these. We don’t need to read the list. So you can have sector atrophy of the iris. And you can have this spiral iris, like on the right picture. Where the fibers are not radial, but they’re twisted. It’s like you put your fingers in a bicycle spoke and turn the spokes of the bicycle wheel. Does that make sense? Can you say it? Just some more examples of iris atrophy. Some of this is laser iridotomy scars. Glaukomflecken is when you have deposits behind the anterior capsule of the lens. And so you have this thing that looks like snowflakes. Well, you don’t see snowflakes. We see snowflakes. So looks — a deposit that’s right behind the capsule. It’s not in front. It’s inside. And you can see that in the pathology slide there on the right. Never mind. These are more glaukomflecken. So let me talk about intermittent. Because we occasionally will see this in the US, and I’m sure elsewhere. And it can be very confusing. So they might have intermittent eye pain or headache. If they’re working in a dark environment. It comes and goes, but they never develop a full attack of glaucoma. They might have blurred vision. And sometimes they’ll see halos around lights. So this is the most dramatic case of this I’ve seen. This is a woman who’s 48 years old, a radiologist, so like us, she works in the dark. And so she’s had terrible headaches for years. So she’s gone through many neurologic workups, including two MRIs, CT scan, and even a lumbar puncture. And then she was seen in our neuro-ophthalmology clinic, and our neuro-ophthalmologist — I’m proud — did gonioscopy, and she was found to have very narrow angles. And so we did iridotomies, and she never had a headache again. So gonioscopy is important. So you really don’t see much. You will see angles that are very narrow. So we talked about indentation gonioscopy and all. That you really need to become — especially in your population, with so much angle closure — very good at indentation gonioscopy. So this we saw the other day. But this is somebody — I don’t think we all saw this, but this is somebody with pupillary block. So when I let up on the lens here, you’ll see the angle is completely closed. All you see is some dusting anterior to the angle, and when I push the iris back, it opens completely. I’m gonna show that again. And then when I let up, you can see the iris comes up and the angle is completely closed. So this is somebody you would expect would do very well with an iridotomy. So this is another example. This is somebody who we think — maybe that’s trabecular meshwork there. But when we indent, we can see that it’s not the meshwork. You can see with a corneal wedge, the angle is almost completely closed. I’m sorry. And when we indent, then you can see the angle. Let me know if you ever want to see any of these again. Just one? Or both? Okay. This is my favorite one. The angle looks really closed, but you can see when I indent, you can see all the way down to scleral spur. Pigmented trabecular meshwork. And I’m backing up, just to show that I’m pushing so hard that the cornea is folded. So we had a gonioscopy talk yesterday, and so not everyone was obviously there, but this is a really great technique. You need a small lens. Posner, Zeiss, Sussman. Not a Goldmann. And all of these videos are on my website, so they’re free, and you can go look at them. This is the other one. It looks like that’s the trabecular meshwork, but then when we use the corneal wedge, which is also on the website, we see that the angle is almost completely closed. That’s a simple A-C line. It’s not trabecular meshwork. And then when we indent, you can see all the way down the trabecular meshwork, but it looks like there’s some low synechiae there too. So chronic angle closure is just like primary open-angle glaucoma. These are people who have really no symptoms, other than visual field loss, and they have gradual decrease in peripheral and night vision, late loss of central vision. They behave exactly like primary open-angle glaucoma. It’s just that when you do gonioscopy, you see that their angles are closed. In the US, this is more common in people who are Black. Of African heritage. So they would have, really, everything that you would see in primary open-angle glaucoma, but with narrow angles, and often would have synechiae. So there’s a long differential diagnosis of angle closure. Plateau iris — that’s a different talk. Phacomorphic glaucoma. So if you do — if one does an iridotomy, and the angle is still mostly closed, you should think about plateau iris or phacomorphic. So plateau iris we talked about in the gonioscopy talk. Go to that section on indentation on the website, and it will show you what plateau iris looks like on indentation. If I see somebody whose angle is still really narrow, I will do biometry, to see if they have a big lens in a little eye, like the lady we just operated on. So nanophthalmos is just extremely small eye. And so that’s somebody whose axial eye length is usually under 20 millimeters. 20. Aqueous misdirection is malignant glaucoma. So those are usually people who’ve had surgery, and the anterior chamber is usually completely flat. People can have swelling of the ciliary body from some medications that can cause the anterior chamber to become very shallow or flat. In the US, it’s especially topiramate, which is especially for — I think it’s a psychiatric drug. You can also get it if you do a lot of panretinal photocoagulation or scleral buckle. And you can have a shallow chamber from a tumor, but hopefully you would not miss that. So pupillary block is really part of these first three. So it’s not separate. So people with plateau iris often have pupillary block, and then you do the iridotomy, and they’re still narrow angle. And these people also have pupillary block. So laser iridotomy is usually what we do, like we’ve been doing today. Surgical iridectomy almost never you would do, unless you have somebody who is mentally not able to be at the laser. So iridotomy, you just make a hole in the iris, allow the fluid to come through in the anterior chamber… Laser iridotomy. So we were talking today — I like to make them with argon laser, followed by YAG laser. So you get this — it looks like a little trephine hole. It’s very easy to see afterwards. But the YAG works great. So the other important thing is that if you have pupillary block and you do a laser iridotomy, afterwards the angles are hopefully open, but they’re not wide open. They’re not wide open like a myopic patient. These eyes are still small, and so they still have crowded angles, but hopefully not occludably crowded. So even after iridotomy, you have a big lens and a small eye, so the angle will still be shallow, but hopefully not dangerously shallow. So if you see somebody who has an iridotomy and their angle is grade 4, they probably didn’t need the iridotomy. If you see somebody who has an iridotomy done, and then afterwards, the angle is really wide open, they probably didn’t have angle closure. So this is somebody with very narrow angles. This is a Van Herick test. And you can see how there’s almost no fluid in there. We do the iridotomy, and now the angle is still not very deep, but it’s much deeper than it was before. I’ll show that again. So this is before iridotomy. You use the thickness of the cornea as a ruler, and you can see the anterior chamber is less than a quarter, maybe less than an eighth of the corneal thickness. And now after the iridotomy, it’s much, much deeper, but it’s still not deep. Do you want to see that again? Or no? Do we need to see that movie again? We’re good? So if somebody — did you want to see it again? Okay. So before laser… You all know how to do Van Herick tests? Okay. Do the laser, and then this is after laser. Much deeper. But still shallow. So would we do gonioscopy? Absolutely we would do gonioscopy. But this is just a demonstration to show… Yeah. I always do gonioscopy. It’s my life. So if someone has acute angle closure, use all the drops. Aqueous suppressants, timolol, dorzolamide, brimonidine. You hold on pilocarpine, cholinergics, until the pressure is low enough that the muscles can work. So it doesn’t help to put it in when the pressure’s 50. And then systemic carbonic anhydrous inhibitors, like Diamox, and sometimes hyperosmotics, like mannitol. So there’s a technique where you can just push on the cornea, like indentation gonioscopy, and break an attack. I don’t know if I’ve ever done this. But you just push in and drive the iris back. So you can use a gonioscopy lens, or you can use a tonometer tip, like a Goldmann tonometer tip. Right. So the kind of gonioscopy lens would need to be a small lens. Zeiss, Posner, Sussman, like you do indentation gonioscopy with. And so some people — I’ve had effect just breaking the attack by pushing the iris back. So surgical iridectomy — only if you can’t do an iridotomy. You can do an iridoplasty if the cornea is really cloudy, to pull the iris out of the angle, until the cornea is clear enough to do an iridectomy. Or iridotomy, sorry. So I’ve only maybe done two surgical iridectomies in my life, because if somebody has to go to the operating room, their pressure is very high, I would do a trabeculectomy with an iridectomy, because you’re not guaranteed that the pressure will come down, just doing an iridectomy. That make sense to people? So you can do goniosynechialysis to break synechiae. So if you’re doing cataract surgery, you can pull the synechiae out of the angle as a treatment for angle closure. So this usually only works if the synechiae have only been around for six months or so, or less. And remember that if you do trabeculectomy in somebody with angle closure glaucoma, these are the people who are at most risk to develop malignant glaucoma. Trabeculectomy angle closure patients. So I use — when I normally do trabeculectomy, I put one drop of atropine at the end, but no more. But with these patients, I leave them on atropine. So don’t forget the other eye. So if you have attack of angle closure in one eye, you should be thinking — I need to do an iridotomy in the other eye. So the risk is 40% to 80% in 5 to 10 years. So you’ll look really stupid if you don’t think about the other eye. So when someone comes in with an acute attack of glaucoma in one eye, they have a lot of systemic stimulation. They’re emotionally distressed. And that can dilate the other eye. So when do you do a prophylactic iridectomy/iridotomy? Just somebody who doesn’t yet have high pressure. You would do it if they have 180 degrees, where the iris is touching the trabecular meshwork. If they have narrow angles and their pressure is high, that’s actually the first one there. If they have synechiae. If they have evidence that the iris has been hitting the trabecular meshwork, which would be having more pigment above than below. And we already talked about the history of angle closure iridotomy in the other eye. You definitely should think about it. So even after you do the iridotomy, you have to do gonioscopy. Because these people can still have narrow angles from big lenses or plateau iris. So at least in the US, sometimes people will say: Your angles are narrow. Be really careful going into a dark restaurant or a movie theater. You should never tell anyone that. If you think their angles are too narrow, you should do an iridotomy. So we talk about mixed mechanism glaucoma. That’s somebody who has angles that are closed and then you open them, but their pressure stays up. That’s one type of mixed mechanism. So they’re angle closure plus open-angle. Mixed mechanism. You can also have mixed mechanism the other way. You can have somebody who starts off as open-angle glaucoma, and then their angles get narrow over time. That can be because their lens is growing, or they have exfoliation, and their lens is moving, or cholinergic drugs. Especially think — at least in our population — we think about exfoliation. Because the lens gets loose, and then moves forward. So there’s this study that just came out last year in Lancet, called the EAGLE study, and I think you should all read this study. I think it’s really important. And in their study, they show that perhaps the best treatment for people with very narrow angles or even angle closure is phacoemulsification, even if the lens is clear. So this is a little hard to read here, but it’s Azuara-Blanco, Lancet, 2016. Really important, I think, for you all to read that paper. So what they did was they did a randomized trial, and they compared doing iridotomy or doing clear lens extraction for people with angle closure. So they did this in 30 centers and 5 countries. And the patients — there’s a lot of patients. They had to be over 50, but without cataract. And they tried to have a big Asian contingent, so 30% of the study were Chinese. So those who had phacoemulsification had better quality of life. They felt that they were healthier, they had better vision, even though they didn’t have cataract before. They had lower pressure — only by 1 millimeter — but they were on lots less medicine. 21% were on medicine, versus 61% with iridotomy. So this, I think, is gonna change the way I practice medicine. It’ll probably change the way all of us practice medicine. So definitely worth reading that study. And if I see somebody with really narrow angles, since my biometry is right across the hall, I will measure their axial eye length and their lens thickness. And if they have a big lens in a small eye, I would just do phaco. So this is the summary of that study. It says clear lens extraction showed greater efficacy, was more cost-effective than laser peripheral iridotomy, and should be considered as a first line treatment. So let’s just talk a little bit about nanophthalmos. Nanophthalmos are really difficult eyes to take care of. These are eyes that are mostly normal, except that they have really thick sclera. So they’re different from microphthalmos, which is a disorganized little eye. Nanophthalmos is a little eye that structurally looks normal. So these are sisters. They have very little eyes. Big hyperopic refraction. So they get angle closure early in life. They have very thick sclera. And not only is it thick, but it’s not permeable to the flow of aqueous through the sclera. So if you just — if you saw somebody, and they had a really little eye, and you order their 45-diopter implant lens, and you do cataract or glaucoma surgery, they will get horrible choroidal effusions. So you should always think of this in people when you have to order a very strong plus lens, like 40 diopters. Always make sure that they don’t have an axial length less than 20 or so. So this is somebody who one of my partners asked me to help him with, because they had a lens — axial length is 21 millimeters. That’s actually longer than the lady we did today. But we did echo, and we calculated her implant lens as 51-diopter implant lens. So that should get you thinking — something’s wrong. And when we do echo, you can see how thick her sclera is, with that yellow line there. I mean, it’s obviously very thick. So you can treat this. You can prevent — it’s a dominant disease. And so what you want to do with nanophthalmos is to not do surgery, if you can help it. If they have any kind of narrow angle, you should do iridotomy early, and if you have to do surgery, like the one I showed, then we make windows in the sclera to thin the sclera, so they don’t get choroidal effusions. So when we do surgery — like that lady I showed — we end up doing what are called scleral windows. We take part of the thickness of their sclera away, in a 4×4 triangle down below. Inferonasal, inferotemporal. So that the fluid can leave their eye. Otherwise, they’ll get choroidal effusions. So you have to be on the lookout for this. If you order a very, very high-plus lens, think about nanophthalmos. So… Any questions? Dr. Tri?>> So if the patient suffers from acute angle closure, what is the suitable time to do the trabeculectomy surgery?
DR ALWARD: Well, it depends. If you do iridotomy, that might be all you need. Is that what you’re asking?
>> If a patient suffers from acute angle closure, what is the suitable time to perform trabeculectomy surgery on that patient?
DR ALWARD: I would perform trabeculectomy if I couldn’t control the pressure with drops. So that might be 10 years. It might be 2 weeks. But these are patients you want to be very careful about operating on. Especially early. Because they get malignant glaucoma.
>> So it would still be medication first?
DR ALWARD: Oh, yes. Yeah. For angle closure after an iridotomy? Yes.
>> Even though they had acute angle closure?
DR ALWARD: Yeah, I think if they have acute angle closure, and you can break it with an iridectomy/iridotomy, and their pressure comes down, I don’t think you need to do a trabeculectomy. Why do I use two different lasers? It’s just because they’re more attractive. I find for somebody who has — for somebody who has blue irises like me, I would just use the YAG. Because blue irises are so thin and pathetic, it’s just so easy to get through. But for dark irises, then if you use the argon and a very high powered, short duration, you can make a hole all the way down to the pigment epithelium, and then use the YAG to clear out the pigment epithelium. And it makes a very clean opening, so that 10 years from now, when you look at it, there’s no question in your mind that it’s open. In my hospital, the lasers are in the same room, so it’s very easy for me. I use the argon to create a little perfect hole. But the argon doesn’t get through the pigmented epithelium easily. So sometimes just one shot with the YAG blows out the pigmented epithelium. The iridotomies are much easier to tell that they’re open, so when you look at them 5 years from now, there’s no question that it’s open. And it’s much better for getting through really dark irises. I don’t know that the iridotomy is maintained for longer. It’s just — you have two things you’re trying to do. One is to make a hole that breaks a pupillary block. But the other is to make a hole that is obviously open when you look at it later on. And if there’s all sorts of little fibers in there, it’s very hard to tell sometimes. Makes a perfect hole. Yeah. It’s not necessary, but it’s nice. So I would not buy an argon laser just to do this. I mean, we use it for suture lysis. For me, that’s really important. But if I had to choose argon or YAG, I could only have one or the other, I would definitely have YAG. There’s some questions… Do I need to… Do I need to push anything? Or just answer? So there’s a question from Amata Lee. Do you advise to do lens extraction to prevent future attacks? I think I will be thinking that more, based on the EAGLE study. And so Callie made copies of the EAGLE study. We can maybe pass those around. That was really sweet of her, to do that. Do you do one or two iridotomies? There’s really no reason in most eyes to do two. I would just do one. Sometimes you’ll do two if there’s an anterior chamber lens or something that can block one. But just for pupillary block, you only need one. What is the size of lens you would consider for clear lens extraction? Well, if they have — this is in transition. So with the EAGLE study, it doesn’t seem like the size of the lens — it doesn’t matter. It’s a lens big enough to cause pupillary block. So I think this is all in transition, based on this study. So let me go to the questions. So which of the following is a major risk factor for developing pupillary block. Male gender. So it’s female, correct? Hyperopia. Everyone knows it’s hyperopia. What would you think if somebody had — a -10 myope, and pupillary block glaucoma? Is there any disease that would cause that? So spherophakia would do that. So if you see somebody with a -10 myopia and pupillary block, it’s spherophakia or ectopia lentis, where the lens gets round and into the pupil. So hyperopia. You guys all got that. Sorry. I somehow… Question two. So of these choices, what is the most definitive treatment for pupillary block angle closure? How many would say phacoemulsification? Way to go. Okay. In nanophthalmos, what structural abnormality places the patient at risk for postoperative complications? Small pupil? Liquid vitreous? Thin and floppy iris? Thick sclera? You guys are wizards. So the objectives — just again — recognize pupillary block angle closure as a common form of glaucoma, recognize it as a leading cause of blindness, especially in this part of the world, recognize the major risk factors. Hyperopia, female, older age. Really pay attention to family history. Warn family members. We treat it with iridotomy, and now maybe phacoemulsification. And again, warn the family members. So that’s my website, if you ever want to look at more gonio or something. Any questions? So indications for phacotrabeculectomy? That’s a good question. I mean, I think if they have — if someone has synechiae, very high pressures that you can’t control with medications, it may be that just taking the lens out and maybe taking the lens out and doing a goniosynechialysis would be enough. But you don’t know. And so in that case, I would probably do a phacotrabeculectomy. Did you want to… You can translate.
>> I can ask you a question about glaucoma draining devices. I have a patient with encapsulation of the implant. And after cutting the capsule off, about 2 months, the IOP is raised again. And how I can manage this patient?
DR ALWARD: So this is talking about the earlier talk and the surgery. So if you have somebody with an encapsulated bleb, what can you do? So the blebs often — Baerveldt or Ahmed, but especially Ahmeds. Less so Baerveldts. They’ll have this thick dome, and then you put them back on aqueous suppressants, and often it will soften, but not always. So should I translate that? Or just… I put my plate so far back that needling is not a great option, usually. So that if I can’t control them medically, I would usually put a second plate down, inferonasally. I do a lot of second plates. I leave the first one in place. And then I would put a second one down below. Inferonasal. So inferonasal — because especially Baerveldts are so big that they’re under the superior and lateral rectus muscle. There’s not any room superonasal. It’s not that hard to put them in inferonasally. I do not remove the first one, because I think the first one is still working.
>> I think because it’s scarring the conjunctiva. So we could not move it out anymore. Without harming the eyes.
DR ALWARD: It’s hard to take out a plate, although we do it. But there’s no reason to take it out. If you do ultrasound, even if the pressure’s high, you’ll still see that there’s some fluid around the plate. And these patients do really well with cyclophotocoagulation, because there’s some outflow, but not a lot. And if you can just turn down the inflow, they often will do okay.
>> You mean CPC with low energy?
DR ALWARD: Just CPC, but maybe not 360 degrees. Maybe 180 degrees. So sometimes we’ll have two tubes, and then do CPC. I hope I don’t have to. But I do. That’s a great question. So the question is: If you see somebody — you look at their family member. So I would have somebody look at my brother. And if he’s normal, would I worry about his children? Is that part of the question? And would I treat him or the relative if they didn’t have a very narrow angle? A — I don’t think it skips generations, so I don’t think I would be too concerned down the road. And B, if they’re hyperopic and their angle is kind of narrow, I might do an iridotomy on them, but if they otherwise look really good, I would not worry about them. Is that translatable? We’re losing our translator. I don’t blame her. Yes.
>> I have a patient with scleral buckle (inaudible), and he had to have an Ahmed (inaudible) surgery, and do you know how we can do the Ahmed one in this case, because I have to cut the scleral buckle. Because I have a tube both to the sclera and to the anterior chamber, but the scleral buckle is 360 degrees.
DR ALWARD: So I put many, many tubes — Ahmeds and Baerveldts — over buckles. If it’s just an encircling band, it’s very — it just goes behind them. And then I suture it to the buckle and the capsule around the buckle.
>> You mean below? Over?
DR ALWARD: I slide it past the buckle, and instead of suturing it to the sclera, I suture it to the buckle. Because the buckle, like a Baerveldt, has a thick capsule, and it doesn’t go anywhere. If they have a sponge, if it’s a big sponge all the way around, then it’s really hard.
>> So will you suture the tip?
DR ALWARD: No, I suture the plate to the buckle. You know, there’s a thing called a Schocket shunt, where you put a tube in the capsule around a buckle. Nobody does that. But suturing to the buckle is easy, because the buckles indent. And it’s very safe. As opposed to suturing to the sclera, which is not normal sclera. And so I never tell the retina doctors I do this, but I sew it through the capsule of the buckle, through the buckle, and then it’s really easy.
>> So the tip will be under the buckle?
DR ALWARD: No, the tube will just lie on the surface. It’s just like you were doing a regular Ahmed or a Baerveldt. On the surface of the sclera. I can draw it for you, if you want, when we’re done. Other questions at all? Everybody tired?
>> I guess they’re tired.
DR ALWARD: I don’t know if there’s something that follows this. Do we know? I will find… The answer is no. So I think we’re done for the day. Can we use what? So that’s a really good question. Can you use prostaglandin analogs like latanoprost or travoprost in an angle closure? It would be my last choice. Unless there’s a little bit of open-angle. But some people think that it allows fluid to go through the iris. I don’t know. If you’re desperate, I would try it. But I wouldn’t expect it to work very much. Because the ciliary body face is farther back than the trabecular meshwork. So if the meshwork is covered, the ciliary body face is covered.
>> He means not (inaudible) cause more inflammation?
DR ALWARD: I think the whole prostaglandin inflammation thing goes back to — in history, prostaglandins are part of the inflammatory cascade, and so — but there’s a million prostaglandins. And so everybody was afraid to use prostaglandins in eyes with inflammation. But I think we’ve gotten over that. I mean, it just doesn’t seem to do much causing inflammation.