Lecture: Small Pupil Management

Learning Objectives of this lecture are:
• To be able to understand the causes of small pupil during cataract surgery
• To understand all the difficulties encountered during cataract surgery with small pupil and their consequences
• To learn the various methods and techniques to tackle the problem

Lecture location: on-board the Orbis Flying Eye Hospital in Chittagong, Bangladesh

Lecturer: Dr. Suhas Haldipurkar, Laxmi Eye Institute, Panvel, India


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DR HALDIPURKAR: So objective of this lecture is to be able to understand the causes of small pupil during cataract surgery and to understand all the difficulties encountered during cataract surgery with small pupil, and finally to learn the various methods to take care of them. We all know the common causes of small pupil, as we touched this topic yesterday. You can make it out by the picture there. The top one shows you a chronic uveitic case with a severe amount of posterior synechiae. And the lower one clearly shows you a moderate form of pseudoexfoliation. Even with age, the pupil tends to come down. That’s a point we have to remember when we are putting a multifocal lens, because sometimes a multifocal lens, which is dependent on the pupil, they would give bad results as you progress in life. Postuveitic cataract, obviously, with posterior synechiae we touched. Even diabetic patients will have smaller pupil. And with floppy iris, they may start with a small pupil, or a pupil that refuses to dilate fully, or a pupil, by the time you progress in your surgery, starts becoming small. It’s also a big issue. High hyperopes do have. And in the olden days, when the patient used to be on miotic therapy for glaucoma, they would have such small pupils that the pupil just wouldn’t dilate at all. And doing cataract surgery in those days — we used to do broad iridectomies or sector iridectomies, and open up the pupil. But, of course, if you do it today, we’ll do a pupilloplasty. And, of course, neurological conditions should also be remembered. Now, what are the problems encountered during cataract surgery with small pupil? Literally every step, except maybe making a tunnel, which doesn’t involve entering the eye, is affected. And the first affected step is rhexis. Obviously because the pupil is very small. It all depends on how small is the pupil. If it’s 2 millimeters, 3 millimeters, you will not likely do a rhexis, which is 3 millimeters size. If it’s 4 millimeter and you are used to making a 4 or 4.5 millimeter — 3 or 4 millimeter, with some experience, you still can make, but by and large, pupil is definitely a problem. Because you can have some ill judgment in the size, shape, and you wouldn’t even know if it’s extended too much into the periphery. Hydro procedures, there’s inability to judge the correct dissection plane, leading to difficulty in rotation of the nucleus. Ideally, when you do phaco, first the most ideal step in hydrodissection is cortical cleaving hydrodissection. Now, cortical cleaving hydrodissection will create a plane within the capsule, and the entire cortical matter, along with the nucleus. And to do that, you have to just try and go under the rhexis. Tent it up a little. Inject it, so that the fluid will pass right across and comes out from the next. What it does is: You need to do a minimal amount of hydrodissection. And once the hydrodissection is done, it rotates on its own. But the major part is, at the end of phaco, you are left with very little cortex to be removed. Sometimes with a good cortical cleaving, hydrodissection, you may not have to do cortical wash, because most of the cortex, the epinucleus, comes along. And the major brunt of this problem is borne by the phacoemulsification technique itself. The smaller the pupil, obviously your red reflex is poor, and red reflex, to a large extent, controls or guides a phaco. And that, you understand, when you have to operate with no red glow. Meaning if you have set your microscope on an oblique light by mistake, and you are not getting a red glow, even in a soft cataract, you find it difficult to find a judgment. Suppose you have a patient with vitreous hemorrhage, where there is no glow, and you still have to continue with your phaco. It is a difficult task. Similarly, when the pupil comes down, the first thing that happens is the glow goes away, and it’s difficult for phaco, because these are some of the impediments to proceed well in phaco. You cannot judge the depth of the trench, so there’s always a risk. See, when you are doing your trench, you are guided by? You are guided by the change in the color. That only tells you how deep your trench is. Because if you have a shallow trench and you want to crack it, it’s difficult. So you want to make it a little deeper. So that is difficult. And yesterday we saw how we were catching the pupillary margin, because the pupil there — it was not because the pupil was small. It was because it was recklessly done. But even if you are careful in a small pupil, you are bound to catch the iris. See, it’s a vicious circle. The moment you catch the iris, the iris gets irritated. The pupil further comes down. And it creates a problem. And inadvertent capsular catch or capsular trauma with chopper. And very often, as a beginner, you are requested to stain every capsule. That’s because, one, by staining, it helps you do the rhexis. But the major part is: If you have stained your capsule, and when you’re chopping, very often, even an experienced surgeon with a sharp-tipped chopper will directly go on the capsule and tear it. And in a small pupil, you are bound to do it. And to help you avoid that, sometimes it’s better to stain, so that even by mistake your chopper is going on the capsule. The staining will prevent you from doing it. Then there’s always the difficulty in cortical aspiration. We saw it yesterday, when I had to put the lens into the bag, and I was not seeing the bag, because the pupil was small there. I had to use hooks to open it up. That means for a good, uneventful phaco surgery, the pupil should be broad. Your rhexis margin should be visible. In small pupil, all these things are hampered. So what are the consequences? There’s increased risk of iris damage that we just spoke. When you catch on the iris, there’s always iris bleed. And when… Now, iris prolapse from the wound is not directly related to it. Smaller rhexis does happen, because the pupil is small. Incomplete evacuation we just discussed. And then major problem comes when you have to put a toric lens. When you want to put a toric lens, you have to have proper alignment. And with pupil, see, the lens has got those marks on the steep axis. They are in the extreme periphery. The lens is 6 millimeters. The edges of the marks are there ’til almost 5.5 millimeters away. So in a small pupil which is 4 millimeters, it is impossible to see the edge of the lens. So that means in spite of a patient going in for a premium lens and paying more, if you can’t get the lens in the proper axis, your surgery has failed, which the patient will not accept. So these are the cases where your pupil has to become big. So how do you do that? Now, these are the fallout of a small pupil during cataract surgery. And because of inadvertent catching of the iris. Once you catch it, you leave behind your signature years later. When you see, it reminds you: When someone sees the patient, he is bound to be curious to find out who did this surgery. And then, you know, make up his own mental image of you. How could this doctor do this and damage the iris? Once you catch it, it gets depigmented. Even if it’s a soft touch or a hard touch. So that brings us to the question: What is a small pupil, to be considered a small pupil? 2 millimeters is definitely small by any standards. 3 is also small by any standards. 4 millimeters, for many people, may be manageable. It all depends on your expertise. So the pupil size is relative to surgeon’s skills, techniques, and, of course, the intraoperative situation. When I say intraoperative situation, at what stage you are in the phaco? Let’s say you are in the beginning, where rhexis is yet to be started. You hit it. You have to have something. And the easiest thing, as a beginner, is to use hooks. To open up the pupil. But hooks has its own downside. When you put a hook, sometimes it damages. Sometimes it disfigures the iris. Especially if it’s a floppy iris, and you use hooks. Because that iris tissue is not a normal tissue. You know, it always has a tendency to billow. Head into your side ports or into the main opening. Again, it depends on, like I said, the iris tissue properties. If it’s a floppy iris, you’ll need a different management. If it’s a fibrotic kind of a pupil, you will think of other management. So what are the overall strategies? One way is to go by — the safer way is to go for pupil expansion techniques. And the second thing is to rely on surgeon’s techniques. Depends on your expertise level. Sometimes you will not need any additional procedures. But, well, today, when additional procedures are so easily available, there’s no point in being heroic, because it’s not your eye. It’s someone else’s eye. And the key points for decision making obviously are: What is the pupillary diameter you are dealing with? Let’s say if it’s a 4-millimeter, and you put a toric lens, you definitely. If it’s a 4.5 millimeter, and it’s a floppy iris eye, you will 100% go in for it. So the surgeon skill and techniques obviously would depend: Once you have done your rhexis, how do you proceed with phaco? Let’s say presuming that here you have 4.5 millimeters or 4 millimeters, and you manage to do your rhexis, and then you want to go ahead with the surgery. First and foremost, you can use a viscoadaptive viscoelastic, like Healon 5. Which has the mechanical property: Just by injecting, you can open up the pupil. And even Viscoat is not able to do that. But in that respect, viscoadaptive — that is, Healon 5 — is an excellent dispersive viscoelastic. Technique-wise, you can decrease the fluidic parameters. Now, what are fluidic parameters? That brings us to phacodynamics. Like yesterday we discussed, the fluidic parameters will be bottle height, aspiration flow rate, vacuum level, the power. These are the four fluidic parameters. So what-all can you do? You can lower the bottle. You can decrease the aspiration flow rate. You can decrease the vacuum. You know, by that, the turbulence in the eye is reduced. There are several techniques. One for phaco making, one is the trenching. With a small pupil, trenching is difficult, so it is out. Then comes phaco chop. Or stop and chop. Even so, stop and chop cannot be done, because you have to do a trench there. Then comes phaco chop. In phaco chop, you have two. Either it’s a vertical chop or a horizontal chop. For a horizontal chop, your chopper has to travel to the equator of the nucleus and come back. And here, because it’s a small pupil, you cannot do horizontal chop. That means you are left with a technique where you’re going to use — do something only within the central portion. And the central portion can be handled only by a sharp-tip chopper in the center, and the technique is called vertical chopping technique. And very often, I have realized that once you start doing phaco, and the pupil comes down, and it’s too late for you to stop phaco and go back to putting a ring or hooks, what we have done is engage a piece, do a vertical chopping, get it into the AC, and do an AC phaco. Ideally, you will do an in-the-bag phaco. As a rule, all the phacos should be in the bag. But in it case, you are to bring it into the chamber. If you are to bring it into the chamber, you have to first have a good viscoelastic in the chamber, to coat the endothelium. If you decide to put Healon, now, Healon — the moment you start phaco — is gonna get absorbed. Now, we have to remember one thing: It’s always a confusion in there, by… What is the viscoelastic do I use for phaco? Right when only Viscoat — Healon was available, we would vouch by it. But we have realized: You inject viscoelastic, you start phaco, the moment you go into aspiration, first thing that gets absorbed is Healon. Instead, if you use methylcellulose, which is not as much cohesive as Healon, it’s more of a dispersive. It stays there. Although that’s not ideal one. The ideal one is sodium chondroitin sulfate, which is Viscoat. If you put Viscoat, it stays there. So in this case, what you do is: When you decide that I have to go into an inner chamber phaco, come out, inject viscoelastic like Viscoat, get it almost to coat the endothelium, and then go with the phaco. And that’ll at least not put endothelium to additional danger, because you are getting the pieces into the anterior chamber. As a rule, phaco should never be done in the anterior chamber, but here you have no choice but to do it. And obviously the choice between coaxial and bimanual… So bimanual will be… Anywhere we use bimanual, you have the ability to use bimanual in a more consistent way. Just like, for me personally, I use coaxial phaco. Coaxial irrigation/aspiration. Because I find that it gives you consistently deep chamber, and it’s quick. Because the amount of fluid that goes in through a coaxial cannula is much more than what goes through a bimanual cannula. So that’s what I use. But here obviously you can’t use it, because as it is in a large pupil, going in subincisionally to get cortex out is difficult. And with small pupil, it’s literally impossible. So now let’s go to…

>> Sir, you are telling that, in this case, in small pupil, we need to bring our cortical matter to the anterior chamber, and during this time, we have to put that chondroitin sulfate, that is Viscoat?

DR HALDIPURKAR: That is what I am talking about before phaco.

>> Before phaco. And you have said that if I put the Healon, then it will quickly absorb? But one thing. The Healon that is adaptive type of ocular viscoelastic device, that has both the biphasic property, that is… In low flow, it acts as an adaptive, cohesive, and in high flow, it acts like dispersive. So if I use the Healon 5 or Healon GV, do I really need to put Viscoat?

DR HALDIPURKAR: For Healon 5? You don’t need.

>> Okay. For adaptive variety, I don’t need. But for the simple Healon, I do need?

DR HALDIPURKAR: It invariably gets absorbed. See, when you don’t have a choice, you can use it. But the choice between Healon and the chondroitin sulfate is… Viscoat… Why, for that matter, you can even use methylcellulose. Even that will suit. And, in fact, it’s a good habit to be using, you know, like… Every now and then, maybe at least two, three times, during phaco, as a beginner, you must inject methylcellulose. Just come out, inject some methylcellulose, and go back. If you are expert, you can use at the left. Just stop your phaco, stop your irrigation, go over to the left hand, inject some methylcellulose, but the cannula is thick, so it is a little bit bigger. But you can inject it and (inaudible). So that what happens is, especially when you’re working on a hard cataract, the cornea, next day, still has a chance to remain crystal clear. So now how do you step-wise manage your small pupil? Preoperatively, obviously, if you’re suspecting — if you know that your pupil is gonna remain small, use atropine, three days prior, for three days. Then intraoperative, if the pupil still shows size not changing, you can always use Epitrate. It certainly helps you. If it still doesn’t help, then you always have a choice of Healon 5 or Viscoat, to further open up the pupil, and the pupil is bound to open up. If it still doesn’t, that means there are posterior synechiae. One option. So go with the spatula and sweep it. And just release them. It may open up. If it still doesn’t, then you have a choice of using two Y hooks and do a stretch pupilloplasty, and if it still doesn’t help, then finally you have to use pupil expansion devices. But there is another option, which you used to do in the past, and that’s called multiple sphincterotomies. But they were all microsphincterotomies, so that the pupil doesn’t change its shape postop. Are we ready?

>> So they’re ready to broadcast. I’m sorry to interrupt, sir. Yeah, I’m sorry to interrupt, sir. But what we’ll do is we’ll finish and let you finish your lecture, and then you’ll do the OT and broadcast that last case. Okay. Thank you, sir. So hello, Dr. Ramesh. So hello, Dr. Ramesh.

DR HALDIPURKAR: Now, if you had to go step-wise, first step would be viscomydriasis. You can do it with a viscoadaptive substance. And what you have to do is, instead of injecting the viscoelastic in the center, push it in the direction of the iris. And literally push it away. And a good viscoelastic, like a dispersive, it literally will push it away and hold it there. Sometimes it does not. That’s because there’s a small component of posterior synechiae. So fill the eye with viscoelastic. If you suspect that the entire iris is plastered, find a small gap, and through that gap inject viscoelastic, and with this viscoelastic, you can do Viscoat dissection. Or else you can just use your spatula to just sweep it, so that you can separate the posterior synechiae. After that, if the pupil still doesn’t dilate, and if the pupil — if there is no floppy iris — remember this. If there is no floppy iris, you can use two Y hooks to stretch it. It’s called stretch pupilloplasty. If it doesn’t work, then you’re finally left with all these pupil expansion devices. And the simplest one, which some of you might have used, that is iris hooks, then you have iris ring from Morcher, you have Perfect Pupil, which is no more used, then comes Malyugin’s ring, which is very commonly used. Then we have B-HEX Pupil Expander, which is just across your border, from Kolkata, by Joja Surgicals, and it’s an excellent pupil device. Then we have a new one, which is called APX Pupil Expander, which is also from Dr. Assia. It’s a nice piece. Here we are talking about — we are seeing a picture of how a hook is used. And when I later on, either today or tomorrow, show some film, I’ll be more pleased to show you how iris hooks can be used for more than one purpose. There was one thing that was missing. And that was: Multiple sphincterotomies. And I’ll show you this film. Now, this pupil is too small to inject your Malyugin’s ring. If I try and do stretch pupilloplasty, the pupil is going to tear in two places. Without tearing it, if I still want to keep the circular pupil, I just have to make very small multiple sphincterotomies, stain the capsule, lower the ring under the viscoelastic, get the Malyugin’s ring into the AC. It requires some practice. It requires you to be ambidextrous. It requires you to use different instruments in different hands, and that gives you finally a pupil that expands. And more difficult or skillful job is to get this ring out of the iris. Again, with practice, you can get it right. And the most challenging portion is to hook it and use a spatula or a flat instrument to press it so that it is taken out. Now, this, in short, is Malyugin’s ring. But believe me, my friends, you need practice. And this practice, if you can do on a goat’s eye, or in a wet lab, and I tell you — for those who are on the verge of starting, or making your phaco better, there’s nothing like wet lab. Wet lab may not give you a hard cataract to do your phaco technique, but there are so many steps that you can learn in the wet lab. Don’t miss an opportunity to go to the wet lab. If you don’t get a goat’s eye, go and grab your own. Bring it, even if the cornea is hazy. You can just peel off the epithelium, or put some hygroscopic liquid on it. Tighten the eye and practice most of your things. Because the wet lab really helps you a lot. These are some of the steps that you just saw. Now, this is a very simple ring. This is from Joja Surgical. It is less expensive than Malyugin’s. And it’s much easier to — you just push it in. It’s a very delicate ring. It goes in. But whatever the ring is, fixing the ring into the iris is a small training. But the best part of this ring is that you just pull it out, even through a 2-millimeter opening. And it’ll come out. But this part requires some practice. And once you have the ring in place, look at this. With single hand, you just pull it out. It comes. And then just hold it with any forceps. And just take it out, and it’s out. So with regards to putting it in and taking it out, it’s the easiest. It’s really easy. The only trick is: You’re to just practice how to get it into the pupil. But that happens for any ring, for that matter. And the easiest is this. This is called Assia Pupil Expander. One of the easiest ones. In fact, I was doing phaco. Halfway through the phaco, the pupil came down. I just decided to use the same side ports, and put those hooks. And just expanded just enough for you to continue the phaco. And at the end of the surgery, after you put the lens, just use a forceps and get it out. Isn’t it very easy? Huh? So what are the advantages of Malyugin’s ring over iris hooks? Although it has four points, it’s actually 8 points, because, between the two points, there’s a portion where also this particular ring helps you expand. There are no sharp edges. There’s no trauma to the iris tissue. It clamps well. Well, there’s a flexibility. There’s no need for extra paracentesis. But hooks have some advantages over the Malyugin’s ring. In a sense, it’s technically much easier. Most of us know how to use it. And we have already used it, and Malyugin’s ring, as you saw, is difficult ’til you get used to it. But once you get used to it, then it’s not a big issue. So, in conclusion, in small pupil cases, my recommendation is to follow the step-wise approach. Two main drivers for the decision to use pupil expander device is size of the pupil and biomechanical properties of the iris. So the lecture objectives, if we have to revisit: To be able to understand the causes of small pupil during cataract surgery. To understand all the difficulties encountered during cataract surgery, and how comfortably to learn to various the methods to overcome the problems. Thank you.

November 27, 2017

Last Updated: October 31, 2022

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