Lecture: Hydrodissection

Hydrodissection is an important step in cataract surgery with phacoemulsification. Freeing up the lens to rotate it is necessary to bring lens material in front of the phaco tip. It looks simple, but for many students, it is the most difficult part of the procedure to learn to do well. This lecture talks about lens anatomy and different techniques for freeing it up from the capsular bag to be able to rotate it.

Lecturer: Dr. John E. Downing, Kentucky, USA

Transcript

DR DOWNING: Okay. We’re going to talk a little while this morning about hydrodissection. And we’re going to start off with a pretest, so you can get an idea of what you already know. Please make a note. We have four questions, and please write down your answer on each one. One… Why do we need to do hydrodissection with phaco cataract surgery? A, debulk the cataract, soften the cataract, free the lens to rotate, or hydrate the lens? Please mark that. And then hit submit at the bottom. Okay. Whoops, question two. I’m sorry. There we go. Where is the cortex typically adherent to the capsule? A, near the equator, B, posteriorly — I’m sorry, B is anteriorly. C is posteriorly. Or D, all around the cataract. So please mark your answer and hit the submit button. Question three. Why do you need to decompress after each injection of fluid? A, to prevent capsule block, B, to push the lens back into the bag, C, to lower the intraocular pressure, and D to prevent capsule blowout. Press submit when you’ve made a choice. Whoops, sorry. Okay. Question four. When would you not want to do hydrodissection? A, if there are loose zonules, B, with a posterior polar cataract, C, with a mature cataract, D, with a very soft cataract. Okay. Well, what is the purpose of hydrodissection? With phaco surgery, you must rotate the material across from the entry wound. You can only access material pretty well directly across from the entry wound. Maybe about 45 degrees to each side. So you have to bring material to the tip and the end so you don’t get all cramped up and have a problem with the capsule. Freeing up the cataract from the capsular bag allows you to rotate it freely, and it’s an important step. It looks very simple. But it’s harder than it looks. And I’ve found that for many residents, hydrodissection is the most difficult step in phaco cataract surgery to do well consistently. It sounds odd, but it often ends up being that way. But if you can get that mastered, it really helps make the rest of the case go well.

>> A simple technique to avoid retained cortex. Cortical fibers develop from the lens epithelium. The lens epithelium is a simple cuboidal epithelium that lines the anterior lens capsule. The lens epithelium can be separated into zones, based on the density of connections to the underlying cortex. The central zone in blue occupies 80% of the anterior capsule and has few connections to the underlying cortex. The remaining zones of the lens epithelium, in red, extend just beyond the lens equator, and are densely adherent to the underlying cortex. The posterior capsule has minimal connections to the cortex. Again, in cross section, the areas of dense attachment to lens epithelium are shown in red, while the areas with weak attachments are shown in blue. The gradient of intracellular connection between cortical fiber layers. Intracellular connections between cortical layers decrease as you move from peripheral to more central cortex.

DR DOWNING: So as you saw, the lens body is formed by epithelial cells, which are near the equator. Then they have fibers which elongate — or part of the cell body that elongates anteriorly and posteriorly, to form the interlocking lens fibers. There’s a loose connection of the fibers to the capsule, anteriorly and posteriorly, but much more adherence around the equator. Usually more with softer lenses than with harder ones. And this is the area which we have to free up, in order to be able to allow lens rotation. You need to inject immediately under the capsule to be able to break the adherent cortex. You generally go out under the capsule a little bit. Don’t put your finger on the plunger yet. Lift a little bit, and then gradually inject until you can see a fluid wave go around behind the lens. If you don’t get a fluid wave, go to another area, and try injecting again. This separates some of the attachments, but often not very widely. And you have to be very careful not to overinject, initially, if you’re having a problem.

>> Exactly how does the hydrodissection impact lens anatomy? With standard hydrodissection, BSS is injected beneath the capsulorrhexis. The fluid goes radially between the cortex and the lens epithelium. Because of the dense connections between the lens epithelium and the cortex, the fluid cannot spread laterally. When the fluid reaches the posterior capsule, a fluid wave is seen as the weak connections between the cortex and the posterior capsule are separated. It prolapses anteriorly as the fluid wave progresses. The fluid wave stops at the posterior edge of the lens epithelium, and the fluid pocket is formed.

>> Here’s the fluid pocket.

>> The lens remains adherent to the capsule by the dense connection between the peripheral cortex and the lens epithelium.

DR DOWNING: Now, there are different techniques to free up the remaining adherent areas, which at this point are pretty much all around. And one that we find works most of the time is to slightly tilt the lens backwards by pressing down slightly in each quadrant near the capsulorrhexis. Then you can see fluid move around from behind the lens to come forward, as you slightly displace it. If the lens doesn’t rotate freely after doing that, you can inject some more under the capsule in another area, tilt it again. It is very important to bring the fluid anteriorly, after each injection, to avoid blowing out the capsule. When you’re injecting, if you watch the capsulorrhexis, you inject until you get a slide increase in size of the capsulorrhexis. Usually no more than a millimeter. If you keep going, you’ll tilt a quadrant of the lens up out of the bag. You can gently replace that, or sometimes it’s safer to just remove it from that position. Be gentle.

>> The capsulotomy is undersized, relative to the diameter of the nucleus. The bag is overinflated. Decompression becomes difficult, resulting in capsular block. Fortunately capsular blowout is a rare occurrence, and is associated —

DR DOWNING: It’s associated with overinflation, without letting the fluid come back forward. That is not something that you want to see, is to have the lens sink back into the vitreous. You can do it… You can blow out the capsule, if you press too vigorously, trying to get fluid to dissect forward. A lot of people say they like to press centrally, but I find that’s not as safe as pressing a little bit in each quadrant, around the capsulorrhexis. If you’re not getting fluid to come back forward, try burping out just a little bit of the viscoelastic, to slightly soften the eye. Then try to gently tilt it. I’ll often displace the lens slightly centrally, while tilting it, to bring the fluid forward. And this is a demonstration of some cases of my doing the hydrodissection. This is a right angle cannula. There are different cannulas that can be used for hydrodissection. Go under a little bit, inject, see that fluid wave go across, then press down slightly in each quadrant. You can see the fluid come back around. And often just one set of that will free it up, and then I will go in, down to the hard part of the lens, and hydrodelineate, to separate the epinucleus. While you’re learning, particularly, I think it’s helpful to hydrodelineate, so you have a layer of cortex and epinucleus inside of the hard nucleus that you’re going to remove with phacoemulsification. Probably don’t have to displace it quite that much. But enough that you can see the fluid come back around. And another. Go out under the capsulorrhexis, lift before you inject, gradually inject fluid until you see a fluid wave go across. If you see sort of a scalloped edge as you go across, it means you are very superficial, which is where you want to be at this point. And then rotate it to make sure it is freed up. And then I hydrodelineate, by turning the tip down and injecting onto the hard part of the central nucleus. Inject until you see a fluid wave. Right there. You want to go across fairly slowly. Then press down near the capsulorrhexis. And rotate. Hydrodelineate. Sometimes you’ll see a separate — it’s called a golden ring. A bright ring that appears when you hydrodelineate. One more. Bring the fluid back forward. Hydrodelineate. That one has a very small central hard nucleus. So just press firmly but hold just enough to slightly tilt the lens back and help the fluid come around. And if you’re having a problem, remove some of the viscoelastic from the anterior chamber. There is a technique called tangential hydrodissection that Dr. John Hart did a video on, several years ago. And this works well as either a primary or a backup technique for lenses that don’t rotate well, after other techniques. It can be done with a Chang right angle cannula, or you can bend a J shaped Binkhorst cannula slightly. It works particularly well with very soft cataracts that often are hard to rotate.

>> Standard hydrodissection is performed first in the subincisional area. Always visually determine that no cortex is trapped between the cannula and the capsule, prior to hydrodissection. Standard hydrodissection is completed once the fluid wave reaches the far side of the lens. Gentle decompression is performed in the center of the lens. Tangential hydrodissection is then performed, until the nucleus with its attached cortex spins freely within the capsular bag.

DR DOWNING: Yeah, inject as you go around, just under the… Whoops, I’m sorry. And he’s showing that he used a J-shaped cannula. This is from several years ago. And you can bend it slightly, to make sort of a 45-degree angle. Dr. David Chang has an excellent book for learning cataract surgery, entitled Phaco Chop, and he includes an extensive DVD with the book. I think it’s the first ophthalmology textbook that included a DVD. So I’m gonna show you his chapter on hydrodissection pearls from that DVD.

>> The Chang hydrodissection cannula is a 27-gauge metal cannula, with a 1-millimeter right angled tip. And the tip is actually flattened, so that there’s a fan-like jet, when used with a 3 cc syringe. It goes right underneath the anterior capsule, with two waves. One hydrodissection, and one hydrodelineation. Because the 45-degree tip creates a little point on the end, so that the cannula itself serves as a dialing instrument to confirm rotation of the nucleus. So here again it’s used with a 3cc syringe. You see the jet of the fluid. And being a right angle, you can get to the subincisional capsular area. And you see that nice slow wave. A scalloped edge means it’s right up against the anterior surface of the capsular bag. The next wave is hydrodelineation, and that’s just by angling the tip inward slightly, and then again confirming rotation, by digging the little angled tip into the nuclear surface. Successful hydrodissection actually means that the epinucleus is loosened, and you see this at the end. It tends to come out in one large sheet, because it’s been loosened from the capsular bag. So again, you slip right under the anterior capsule edge, and if you see that slow wave, you know you’ve loosened not only the epinucleus, but also the cortex. You tip inward just a little bit, to create the hydrodelineation wave. And again, you can confirm rotation with the tip. You want to see a nice slow wave, with a scalloped leading edge, indication that your wave is encountering the resistance of the cortex as it moves. And here you’ll see the epinucleus is actually turning with the endonucleus, indicating that it too has been loosened. And again, although we can’t engage the anterior nuclear surface as peripherally, we can still dig the tip into it, and rotate it around. One of the pearls is to make sure that your chamber is not overfilled with viscoelastic, which of course does flatten the anterior capsule to help with the capsulorrhexis. But then if you burp out some of the viscoelastic, and you’ll see here that the eye is indeed soft, you avoid having too much viscoelastic compressing some of the nucleus posteriorly. You want to have a soft eye so there’s less resistance for the fluid wave to pass underneath the nucleus. Again, leaving the chamber overfilled with viscoelastic compresses the nucleus down into the posterior capsule, creating more resistance for the fluid wave to overcome. The one thing to be avoided is having a brown lens such as this move up right into the back of the capsulorrhexis, creating capsular block. And if you were to overfill the bag, it is possible to blow out the capsule. You see right after that first wave the fluid is used to compress anteriorly, breaking the capsular block. This is a patient with exfoliation and a mature brown lens. You can see that as we tear the capsular flap, the entire capsular bag is moving, indicating that we have very loose zonules. This is often the first indication when you’re doing a capsulorrhexis — you see the wobbly lens, you see the entire lens move, with traction on the capsule, and you know you’re dealing with very loose zonules, as we would expect in this very elderly patient with exfoliation and, again, a brunescent lens. Now, here, because of the laxity of the zonules, our normal steps do not cause a good rotation. And in fact, we see displacement laterally of the nucleus. So if this occurs, it’s because we don’t have enough circumferential zonular tension to anchor the capsular bag, which wants to turn along with the nucleus. So here it’s best not to persist and be overly aggressive. And instead, we’re gonna use a hook and a capsulotomy needle to create a two-point fixation to revolve the lens, thereby loosening it in the bag under viscoelastic, before starting the case. Another time we may have trouble rotating the lens is if it’s very soft. Because like a pillow, it wants to absorb the forces, rather than to spin as a unit. And so here you see that we have difficulty after making our first chop, and rotating the nucleus. So at this point, it is possible to go back in with the right angle hydrodissection cannula, and to rehydrodissect, attempting to loosen both the epinucleus and the nucleus. And in this way, we can see we can complete this case after that initial chop has been made. So the goal of hydrodissection is, first, to be able to rotate the endonucleus. Secondly, it’s to be able to rotate and spin… And then the third goal is to loosen the cortical attachments to the capsule. So here again, in this same case where we’ve had difficulty rotating the lens, it indicates we did not have a good hydrodissection wave, and so here you can see that the epinucleus peels apart, but doesn’t actually rotate away. So we go back in with the cannula, to loosen this last adherent quadrant of epinucleus, before we can actually remove it. And this allows the safe aspiration of a portion of epinucleus. So if your epinucleus is firmly adherent, the hydrodissection itself was not sufficient. The question of whether hydrodelineation is important — for phaco chop, it is very useful. After the first one, tip the cannula a little posteriorly, right there, and that’s gonna create the second wave of hydrodelineation. Basically this cleaves the epinucleus apart from the softer internal endonucleus, and when we proceed now to do phaco chop, we will chop the nucleus and bisect it in half without any sculpting, rotate the nucleus and the epinucleus together — that’s the hydrodissection wave — and then you see how the endonuclear first fragment separates from the surrounding cup of epinucleus. There’s the next chop, and you again see how the endonuclear fragment is separating from the epinucleus, which remains as one large piece, serving as a soft cushion and buffer between the endonucleus and the posterior capsule. This also reduces the size of the endonucleus, effectively, by decreasing the diameter. So for this type of phaco chop technique, creating an epinuclear shell such as this, with the hydrodissection, is advantageous. And here again, showing that our hydrodissection wave was in fact very effective, we can see that this epinuclear shell is loose. And can be aspirated without much difficulty. Once again, the fluid wave that sheared the adhesions between the epinucleus and the capsular bag.

DR DOWNING: I highly recommend Dr. David Chang’s book, Phaco Chop, while you’re learning to do cataract surgery. It is filled with excellent tips, and the DVD explains each section, under different types of cataract. Now, there are some times you don’t want to hydrodissect. First is a posterior polar cataract, where there’s a plaque on the posterior capsule, and it often already has a defect in it, and if you hydrodissect, you can blow that out. So with posterior polar cataracts, you start centrally, hydrodelineate, rather than hydrodissect, and you actually core the cataract from the inside out. You use lots of viscoelastic under the capsule to help keep that separated, and so you don’t get close to that plaque, until you’re near the very end. Hypermature cataracts often have liquid cortex in them, under pressure. You want to make a very small capsulorrhexis, or it probably is a little better to just make a small X in the center, to help relieve the pressure and aspirate it out. If you try to make a standard capsulorrhexis, it will almost always run out to each equator. And it’s difficult, then, to recover from that. If you have very weak or missing zonules, you may want to not rotate the lens. Because rotation is stressful to the zonules, particularly if they are very soft, like in pseudoexfoliation. And there are some techniques to remove the cataract without having to rotate it. Viscodissection is useful and hydrodissection is useful in these, but then I’ll show you one technique that you can remove the cataract without having to rotate it. This is Dr. John Bullock. And Ronald Warwar.

>> A vertical groove is created slightly to the right and center of the nucleus.

DR DOWNING: So you make a… A cut…

>> Note that we are making a vertical… But that is not in the center. It’s offset to the right, approximately 30% of the radius… And what we want to do is we want to divide the nucleus into three roughly equal pieces by volume.

>> Additional viscoelastic is inserted, and the groove is split with a nuclear crack.

>> Now we have roughly 1/3 to the right, and 2/3 to the left. We then make a second groove at approximately a 30-degree angle. Again, roughly 80 to 90%.

DR DOWNING: You want to go down until you get a good red reflex all across.

>> After additional viscoelastic is inserted, resulting in approximately three equal pieces.

>> The one in the left is shaped like a half-moon. The one in the center is shaped like a piece of pie.

>> A Sinskey hook is used to place the fragments for removal. A pulse mode can be useful to keep the fragment in contact with the tip. High vacuum and minimal phaco power are used for removal.

>> And once that fragment is taken in, you can often turn on the vacuum, do your aspiration, and take in the second two fragments, which usually come easily. Note the fragment to the right is now spontaneously dislodged by the movement of the fluid. And we can free that fragment. Approximately 30% of the radius from the center of the nucleus to the right, 30% from where I make the first groove — you swing over a 30-degree angle and make the second groove, and that gives you three equal pieces.

DR DOWNING: But it’s a useful technique in cases where your zonules are very weak. And it’s a good idea to have a number of techniques in your back pocket, for problem cases like that. Now, what if you’re going along fine? The lens is freed up, it’s been rotating very well, and then all of a sudden it doesn’t want to rotate? Hm. That often means you have a capsular tear. If that happens, leave the phaco tip in the eye. Fill the anterior chamber with viscoelastic from the side port incision. Then you can remove the phaco tip, look and see if you do have a tear in the capsule, and use a technique to try to remove the rest of the lens, without managing to push the rest of the cataract back through the capsular tear. Now, we’ll repeat the questions from the pretest. Please mark your answers, and then we’ll go over the correct answers. Whoops. Maybe we will. I’m sorry. Okay, Lawrence, you can show the questions. Question one: Why do we need to do hydrodissection with phaco cataract surgery? A, debulk the cataract. B, soften the cataract. C, free the lens to rotate. Or hydrate the lens. Please mark your answer and click submit at the bottom. Question two. Where is the cortex typically adherent? To the equator? Unfortunately, that says number one, but that’s question two. Is it adherent typically near the equator? Anteriorly? Posteriorly? Or is it adherent pretty much all around the cataract? Make your choice and click submit. Okay, question three. Why do you need to decompress after each injection of fluid? A, prevent capsular block. B, push the lens back into the bag. C, lower the intraocular pressure. Or D, prevent capsule blowout. Pick your best answer. Okay, and question four. When would you not want to do hydrodissection? A, if there are loose zonules, B, a posterior polar cataract, C, with a mature cataract, D, with a very soft cataract. Okay, Lawrence. Let’s go back to question one, show us the choices, and see which is right. Okay, why do we need to do hydrodissection with phaco cataract surgery? You want to free up the lens to rotate it from the peripheral adhesions between the cortex and the capsule. And practically everybody got that. Good deal, very nice. Question two: Where is the cortex typically adherent to the capsule? Near the equator. Yes, that’s the right answer. It is usually pretty well not attached other places. But it does vary. With very soft lenses, you tend to have wider adherence and more difficulty with rotation. Okay, question three. Why do you need to decompress after each injection of fluid? Prevent capsular block. Actually, that is part of the reason that you do it. Push the lens back into the bag. If it comes forward. Lower the intraocular pressure. To lower the pressure, you need to burp out some viscoelastic. And you want to prevent capsule blowout. That’s the biggest reason. If you keep injecting without bringing the fluid back anteriorly, you run a significant risk of blowing out the posterior capsule and losing the nucleus into the vitreous. And it’s not a good thing. Number four. When would you not want to do hydrodissection? If there are loose zonules? Not really. If there’s a posterior polar cataract? There it’s very important not to do hydrodissection. You want to do just hydrodelineation. Work from the center out. Very soft cataracts, it’s important to do hydrodissection. Those are the ones that are often hardest to get good hydrodissection on, and it’s important. And you did very well on that. Okay, well, we have some questions now.

>> All right, thank you, Dr. Downing. You can stop your screen share. So far we have one question.

DR DOWNING: Let me see if I can figure out how to stop my screen share here.

>> It should be at the top of your screen.

DR DOWNING: Okay.

>> So if you just open up the Q and A box right next to share…

DR DOWNING: Oh, okay. In case of persistent capsulocortical adhesions, how do you make a safe hydrodissection? I think the most useful technique I have found in those is to do the tangential hydrodissection. Where you go around, under the capsule, sweep around on one side, as you’re injecting, and do the same thing on the other side. Then again grab, decompress, pushing back, and if you do that two or three times, almost always you will free up the lens. Any other questions? Oh, type the answer. I’m sorry.

>> That’s all right. You can answer live.

DR DOWNING: Okay. Any other questions?

>> It looks like we have a couple more. Do you see those?

DR DOWNING: Yes, okay. What’s the best gauge of cannula for hydrodissection? I generally prefer about a 27-gauge. You can use 26 or so. If you use smaller than 27, it’s often hard to inject quite enough to free it up. Okay. Is a J-shaped cannula superior to a straight cannula? Both of them can be used and work well. I like the J-shaped that you bend, or the Chang cannula. Either one of those works well. Just the standard J-shaped cannula — it’s a little bit difficult to make sure that you have it freed up, other than just subincisionally, where it’s pointing. So if you use a J-shaped cannula, I would bend it about 45 degrees, like Dr. Hart did for his tangential hydrodissection. Opinion on using a 10 cc syringe instead of a 3? I don’t think you can control the injection nearly as well with a larger syringe. 2 or 3 is pretty much ideal. You can control your pressure much easier, and that smaller one is much easier to manipulate in the eye than with a larger syringe. Yes, third is: Is a 26 okay? Yes. Most are either 26 or 27. Why does sometimes hyphema occur after hydrodissection? I’m not sure. I have never had that happen. It could be from being a little bit too rough or… I’m not sure, other than that. But that is not a good sign. If that happens, you need to inject viscoelastic, see if you can figure out where the bleeding is coming from, and then stop and figure out what you’re going to do from that point. Okay, do you want a sudden bolus or a slow one? In between. Inject a little bit. If you’re not getting a fluid wave behind, inject a little bit more. And watch the fluid wave go across. Try to pretty much match the fluid wave going across speed to what you saw in the videos. Okay. Yeah, air works well if you have a small hyphema, yes. Absolutely. Actually, you may be able to see better and do better with air to try to stop a bleed, rather than viscoelastic. Good suggestion. Viscodissection? If you’re having a problem, often it works well. You can inject a little bit under the capsule. Around. And it particularly is useful toward the end, with a posterior polar cataract, to viscodissect the cortex away from the capsular bag. Okay. The fluid wave generally will go radial to the capsule. As it’s going across. From the point of where you’re injecting. Okay, how many quadrants to hydrodissect? That depends on the particular cataract. A good number, you only need to do one to free it up and rotate it freely. But if that doesn’t work, I’ll go across, inject again, and go through the same procedure of bringing the fluid around. You can do as many as you need to. If I don’t get good rotation after two, two standard injections, then I will switch and do the tangential and sweep around as I inject, until you can free up the capsule. Okay, if the fluid wave is not seen, that’s where you generally want to burp out a little bit of viscoelastic, and try again. If it’s not still getting a wave, I would do the tangential hydrodissection, and sweep around on both sides. Okay. If you have lens touch before surgery, how do you plan… Okay. Are you talking about a very anteriorly prolapsed cataract? Essentially you can have a flat chamber, occasionally. I have seen that in patients who have glaucoma with a filter procedure, occasionally. If you cannot deepen the chamber with some viscoelastic, you may have to remove just a little bit of vitreous through the pars plana. You get an instant deepening chamber if you do that. It’s very rare to have to, but it’s nice to know that you can do that. In case of persistent capsulocortical adhesions, how do you make a safe hydrodissection? I would try the tangential sweep, where you sweep around under the capsulorrhexis. Or if that isn’t working, I would probably go to that V-shaped procedure that I showed you at the end. Okay, what precaution do you advocate in case of lens touch? I’m sorry, postvitreoretinal surgery during hydrodissection? Actually, any time if you had a normal depth of chamber, which I think is probably what you’re talking about, but you go in and it immediately flattens, that almost certainly means you have a posterior capsule tear, and you need to be very careful to release the pressure. You may need to remove a little bit of fluid from the pars plana there to deepen it. But that’s a very tricky problem, because you probably already have a capsule defect. Okay, I’m sorry. I can’t quite see the top of the first question up there. In case of preoperative rise of intraocular pressure, I would be very cautious to do anything, if you’re getting a very hard… That may mean that you have a choroidal hemorrhage or choroidal dissection. Often at that point it’s best to stop, make sure you’re closed, postoperatively soften the eye, and come back in a few days. Can rotation in case of a hard nucleus where you can’t see the — okay. Do the hydrodissection… With a very hard cataract, where you cannot see posteriorly… Gently hydrodissect. Watch for the capsulorrhexis to enlarge slightly. About a millimeter. And then you can tilt it to bring fluid back around. Okay. Can rotation be done without being sure of efficient hydrodissection? Yes. If the lens will rotate freely, then you have adequate hydrodissection. So you want to make sure the lens will rotate. And you may not have seen the fluid wave. But if the lens is freed up to rotate, that’s the point to hydrodissection. Okay. Thank you for the comment, Dr. Raj. As I said, I’ve been working with residents many years now. And it looks simple, but sometimes it isn’t. And you need to have some different techniques to be able to… Okay. During a case of anterior capsule tear during capsulotomy, should you do hydrodissection? That depends on how large the tear is. You would want to be very gentle. And see if you can get the lens to rotate at that point. You can sometimes tell by the way the flaps on the tear go whether or not it’s gonna go back further. If it stays pretty — if the capsule around the tear stays pretty flat, usually you’re okay, but you want to be very gentle, and try to stay away from the area of the tear as much as possible. So you don’t push it — or so you don’t tear around posteriorly. Okay. In case the rhexis runs out, do you still do hydrodissection? You need to be very gentle. If the capsular flaps are rising up and flapping around a little bit, that probably means that you do have a tear on posteriorly. I would consider strongly switching to an extracapsular procedure at that point. Because there’s definite risk of pushing the nucleus back through a capsule tear into the vitreous. In case of traumatic cataract, advice? You usually have zonular defects. And each one is going to be individual. Try to figure out how much zonular support you still have. And you want to do everything very slowly and gently. Any time you have a problem. Usually the first thing you want to do is fill the anterior chamber with viscoelastic. Assess your options and the problem. And then try to proceed in the least traumatic way possible. Okay, hydroprolapse of soft cataracts with hydrodissection. And some of the lens in the anterior chamber. With very soft lenses, I’ll usually just go ahead and phaco it there, and try to use as much aspiration as possible and as little phaco power. And those are often hard to rotate. You can sort of viscodissect those out of the fornix. Okay, hard cataracts have very little space for the fluid wave. Exactly. And looking for the expansion is easy when stained with Trypan blue. Yes. I do the same thing. Any cataract that I cannot get a red reflex, so I can see what I’m doing with the capsulorrhexis, I will use Trypan blue. It’s a wonderful help with safety. Okay. Any others? Okay. Case of persistent capsulocortical adhesions? I will usually do the tangential, where you inject all around, under the edge of the capsulorrhexis. And that almost always will free even very soft cataracts up to be able to rotate it. Okay. In case of posterior polar cataract, avoid hydrodissection. Do not hydrodissect. You want to hydrodelineate and remove those from the inside out, and viscodissect the epinucleus and cortex freely. Trying to stay away from that capsular plaque, as long as possible.

>> All right, thank you, Dr. Downing. That looks like all the questions. Actually, we have one more. If you want to just answer that one. Last one.

DR DOWNING: Okay. Using the 26-gauge needle that you use for the rhexis? I have not done that. I think you’re much better using a blunt cannula. I think it’s probably safer and probably more effective. So use either a straight or an angled blunt cannula. I think it’s more useful. If it works well for you, do it.

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January 18, 2019

Last Updated: October 31, 2022

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