Live Surgical Demonstration: The Basics of Vitrectomy Surgery (Part II)

DR MILLER: Good morning, and welcome to our live surgical demonstration of our vitrectomy surgery, the basics of vitrectomy, part II. I’m Dr. David Miller of Retina Associates of Cleveland, working here in beautiful Fairview Park, Ohio, just outside of Cleveland. I’m going to go through some slides this morning, a didactic, and then break to a live surgery, which is set up already with my assistant, and then we’ll come back and do a few questions and some quizzes off the case. So that being said, I think we’ll just jump right in with the slide set. So the basics of vitrectomy surgery part II. I did a lecture about a year and a half ago, that’s also on the Cybersight web. And you can always go back and look at that. Advance, please. Okay, the indications for vitreous surgery. The basics are for diabetic retinopathy, diabetic macular edema, retinal detachments, macular hole, macular pucker, vitreous opacity, vitreous hemorrhage, any type of blocking of the vision by opaqueness to the media or the vitreous, and for vitreous infection. So endophthalmitis, even bad uveitis cases that involve vitritis, we can remove a lot of floaters and do very well. The benefits of vitrectomy. Any time we’re doing surgery, I think the standard of how we’re looking at it is the risks versus the benefits. The benefits in vitrectomy surgery are the improvement of vision. You can improve the central vision by removing a macular hole or pucker or vitreous opacities. In some cases, the macula is fine. You can have a peripheral retinal detachment that’s threatening the macula, or a patient with macular degeneration and vitreous hemorrhage, and in that case, vitrectomy can still be helpful in improving peripheral vision. You can have prevention of visual loss or decline of vision. That’s typically in something like endophthalmitis. Where there’s peripheral detachment, you’re trying to save the macula. And of course there’s altering the natural disease course or stabilization of the disease. I think the classic example is in diabetic retinopathy, where new blood vessels are pulling on the retina, breaking and bleeding, and we can alter the disease course by taking out those blood vessels and putting in photocoagulation with the laser surgery, so there’s not a recurrence. Risk of vitrectomy. You always want to keep this in mind as the surgeon. Infection and endophthalmitis is a very feared — probably the most feared complication, because the outcomes can be so severely poor. Retinal tearing and retinal detachment, which can require reoperation, if not discovered at the time of the original surgery, or if the tears happen postoperatively, at one month or two months. Choroidal effusion or hemorrhage, cataract, glaucoma, and any that’s anesthesia-related is also included in the discussion of the risks. Next slide. So I feel the essentials of vitrectomy surgery — and this is a bit of a repeat from my prior lecture — pre-op evaluation, including a dilated examination, adequate anesthesia. Our case here is being done under local anesthesia. I already performed a retrobulbar block, and the patient is prepped and draped. A surgical assistant is very useful in vitrectomy surgery. Getting the instruments on and off the tray, someone to monitor the machine, help control the infusion and troubleshoot any issues during the cases. Very helpful. Proper wound placement for the vitrectomy is critical. I myself prefer for a pars plana vitrectomy — the working spot is kind of near the horizontals. I’ll demonstrate that in the surgery. Further essentials of vitrectomy is you must be able to see what you’re doing in the eye. Intraocular visualization is truly key. You want to avoid any retinal trauma, so that includes doing a B scan sometimes on a preoperative patient, which I’ll show you on this patient here. You want to control any intraocular bleeding. Very difficult to do the surgery if you’re losing your view from bleeding. Proper selection of vitreous substitutes. When we’re taking the vitreous out, what are we putting in its place? The most common is balanced salt solution, but sometimes we use air, gases, or oils. Tight wound closure is essential. You want to avoid hypotony and the risk of infection. And the surgery doesn’t end when we roll out of the room. You want to do postop checks on day one or day two and again at one week or three or four weeks. So today we’re talking about a case of vitreous hemorrhage. And possible diagnosis of vitreous hemorrhage — very commonly, there’s proliferative diabetic retinopathy, you can also have hemorrhage from a posterior vitreous detachment, where the vitreous separates away from the optic nerve or a peripheral retina and a small blood vessel is torn. There’s a retinal tear with vessel involvement, a retinal detachment with retinal tear, and any source of neovascularization, both retinal vein and retinal-arterial occlusions, choroidal neovascularization from wet macular degeneration can cause breakthrough vitreous hemorrhage, or any ischemic process. Next slide. This photograph here — a few slides showing what we’re doing, of the center we’re working on here. A picture of ourselves — not myself — doing a pre-op evaluation in the pre-op area, looking over the chart notes before we come back to the operating room. And the microscope — it’s nice to have a setup where the assistant can also be looking through oculars, as you see here. I’m a surgeon on the left and my assistant is a physician assistant on the right, who can keep the cornea lubricated, hand me instruments, and also look in the machine. There’s a close-up view of the same photo. The basic three port pars plana vitrectomy is an infusion cannula that you see just above the number three there, also labeled IF, and then you see the light probe, LP, and to the right you see the vitrector. This shows the infusion cannula. Basically how it’s set up and sutured to the sclera in this case. We won’t be doing that today. We’re gonna do a suture that’s 25-gauge vitrectomy, or 20-gauge vitrectomy in older equipment — this can work quite adequately. So placements for these wounds through the sclera and the pars plana, you want to be measuring from the limbus. So this diagram is showing about 2.5 millimeters posterior to the limbus is the parse plicata. You can enter the eye there, but your risk of bleeding is higher. If you get beyond 2.5 millimeters, up to 6 millimeters, you’re probably in the pars plana. I typically will make my wounds around 3 millimeters, so I don’t want to risk wanting to go through the retina. I want to get into the pars plana. This is just a diagram showing how the basics of vitrectomy is performed. You have an infusion there where the arrow is demonstrating the inflow of balanced salt solution, there’s a light probe shining light on the vitreous body, and you can see the vitrector pulling out the vitreous. Here’s a close-up diagram again, showing how the vitreous is going up the port. We also have some special instrumentation that we can use during the case, some of which we may be using today. Here you’re looking at a flute needle or aspiration device to pull blood off the macular surface. We also have different forceps and intraocular instruments activated with our hands. The top is a flute needle, the next three or four images are of scissors and forceps and retinal pick. Here’s a demonstration of a scissor being used to bisect some fibrovascular tissue from diabetic retinopathy, most likely. Retinal forceps are being used to peel away a macular membrane or an epiretinal membrane. And cautery. We can also use cautery in the eye to cauterize active bleeding sites. And we can use a retinal pick. Probably our most common tool is to use a pick to elevate edges of the membranes so they can be grasped. And we can also drain out subretinal fluid to repair a retinal detachment, being demonstrated here, and apply laser photocoagulation to the edges of the retinal break. And then postoperatively, we discuss with the patient what’s going on and what they expect and give them written instructions to take home, with emergency numbers to call if there’s any issues. So safety techniques. You want to confirm the intraocular pressure. You want to maintain your intraocular spatial orientation. You want to control intraocular pressure. Too high or too low are both a problem. If it’s too high, you’ll see the retinal vessels flashing. If it’s too low, you’ll see the eye wall enfolding. You want to avoid iatrogenic trauma, tears and cataracts, you want to avoid bumping the lens of the eye if they’re phakic. You want to avoid traumatizing the retina itself with the vitrectomy cutter or the light pipe. You want to check wound integrity, you want to visualize the periphery at the conclusion of every case. With an indirect ophthalmoscope, to make sure there’s no retinal tears before you leave the operating room. You can get postop day one results that look like this. Just a little bit of injection. Not much redness, very comfortable, and in this case, there’s no sutures. This was done as a sutureless case. So I want to discuss our patient we’re doing today. She’s a 64-year-old lady who is complaining of blurred vision over the last two weeks. Vision is measuring at count-fingers at five feet, and she was diagnosed with a vitreous hemorrhage. She was diagnosed as high myopia post-LASIK. This patient was gracious enough to be our live surgery candidate with this vitreous hemorrhage. What’s curious is we don’t know what’s the source of the vitreous hemorrhage. It comes back to the differential diagnosis. We know she doesn’t have diabetes, but it could be vitreous separation, retinal tear, retinal detachment, branched vein occlusion, branch arterial occlusion — it could all cause hemorrhage in this eye. So here are the B scans, showing the vitreous hemorrhage. The scan on the left shows increased density, probably from collecting of blood inferior to the retinal space. And on the left you can see the shadow of blood there laying on the back of the eye. Okay. We’re gonna break now for the surgery, and I’ll take some questions during that, and I’ll explain what I’m doing too. Thanks. So let me get… Get my gowns and gloves on. Okay? And we’ll be in the case. For those wondering, this is not our only case of the day. I believe there’s nine or ten cases scheduled today. Which is pretty typical at our center. For the surgeon. And this is our first case of the day. Thank you. And my assistant, Michael, has her all sterilely prepped and draped. I did the block before the lecture there. Can you grab my glasses, Christine? And I left on my glasses, because I’m becoming more presbyopic, to do the slides. So that’s another change between the basics of vitrectomy I and II. I’m getting older. So that’s just part of how it goes. So I tend to get comfortable first. I’ll definitely adjust my oculars, adjust the scope position. My chair, my pedals. So everything is at my comfort level. What I typically do. So I take just a minute to get everything lined up. With a nice view. Michael already has the lid speculum on there. That’s fantastic. I want to point out a couple things about that. So if you look at how we caught the eyelashes in the drape here, both above and below, we don’t want these eyelashes hanging into my field where instruments would pass, and they rub against the eyelashes with possible contamination. Even though all the skin was prepped with Betadine, including the lashes, we prefer to keep the lashes out of the field of operation. This is a 25-gauge surgery, 25 gauge trocar and cannula. We’re gonna displace the conjunctiva here a little bit with some forceps, and we’re gonna insert this. You can see the numbers here on the back of the handle. 3 millimeters. Or 3.5. We can measure. And I put this in fairly flat. Meaning a low angle. And I go all the way into the eye like that. You can see the cannula is actually pointed towards me a little bit. It’s not straight up and down. The reason we do that is to make a longer wound for better closure of the… Better closure of the sclerotomy, once we remove the cannula. The other thing I want to point out is I tend to keep these working sclerotomies — this is my first one of the working sclerotomies — fairly near the horizontal. This will be the infusion cannula. That’s inferotemporal. This is superotemporal, working sclerotomy. So we’re gonna put in the superonasal site now. Okay. And we’re gonna remove one of the… Off the sclerotomy site, I’m using the Dutch Ophthalmic or DORIC EVA system, EVA vitrectomy system. I’ve used pretty much every brand of vitrector out there over the years. For the last several years, we’ve been using the Dutch ophthalmic EVA machine, which is the latest on the market from them. Okay. So here’s our view in the eye. We’re gonna make sure we’ve got the view first, because we start the actual vitrectomy action. We’re gonna zoom with the scope, and Mike is gonna focus our wide field system. You can see our retinal vessel there. So I know the retina is not up near my port. And I’m gonna activate the cutter. Again, it’s all about, at this point, not doing harm. So I’m not moving the vitrector around a lot. We’re kind of holding it stationary, letting the vitreous come to the port.

>> Dr. Miller, if you could zoom a little bit more…

DR MILLER: At this point, you don’t want to have to move. Zoom in a little bit more?

>> Beautiful. Thank you.

DR MILLER: Okay. So we’ll let the vitreous come to the port. And not chase the vitreous in a vitreous hemorrhage. Let the machine do the work. I think when I was training, one of my professors told me it’s not like you’re tossing a salad in there. Just kind of be patient and let the machine do the work. You can see the hemorrhage is a little thicker down below, which we expect. And it’s got a little whiteness to it, because it’s been resorbing for a while. We were following this in the office with serial ultrasounds and B scans. To see if it went clear on its own in a timely fashion, and it was not clearing up well. So we’ll use the vitrector. You’ll see me kind of change the direction of the port. Right here, the port on the vitrector is facing me. And what we’re gonna do is sometimes point that towards where I want to go, and take out that thicker hemorrhage. And what I’m watching is my orientation in the eye. That’s a little bubble right there, in the viscoelastic. We put some viscoelastic or some Goniosol, as another option, on the cornea, to keep it moist, so it doesn’t dry out. You can also reapply balanced salt solution throughout the case. Now, I don’t reach directly across the eye, because I know the patient is phakic. We don’t want to be hitting the lens. But the advantage of having these ports on the horizontal is I can reach very inferior or superior, without having to reach across the lens, avoiding lens trauma. Like this. Still out of view? Okay. Yep, I understand. We’ll try and keep it in view during the case. I’m getting some guidance here from Mike, which I appreciate. We’re going to switch sides here. Meaning I’m gonna switch where I got the instruments in the eye. The vitrector and the light. We can grab this bubble here too. We’re gonna take that little bubble off the cornea. All right. So now the view is much better, of course, already, compared to when we started out on the other side. And the vitrector I’ll tend to use… They’re pretty high speed. You can control that a little bit with the foot pedal. I’m not sure if I’m on the screen or not there, Michael. What do you think? Am I on the screen there or not? Well, I think I found our culprit. I can see a little movement down on the retina here, and I can see a retinal blood vessel. So not quite a tear, but we’ll cauterize that. You can get some cautery. Yep. Mike’s gonna get some cautery ready for us. It’s not bleeding currently, but we’re gonna cauterize it, because we don’t want it to bleed tonight or tomorrow and be back where we started. So we can get that. I can reach across the eye here. To get the vitreous on the other side. But I can’t go straight across. I can probably only go out to about the equator, without having to be concerned about bumping into the lens. So I don’t like to really take out too much of the peripheral vitreous. That’s not essential in most cases. And I would say for those starting out you want to avoid the peripheral vitreous and just try and clear the central vitreous. If you can clear the central vitreous and uncover the macula from a vitreous hemorrhage and put some laser in your diabetics, I think you’ll be way ahead of the game. And even I won’t go after blood like this in the inferior periphery. Sometimes we’ll scleral depress and take that blood out, but again, if you don’t have to, you’re better off not. Cautery is out. Okay. On my left hand, I can see a little bit of bleeding from those vessels that were avulsed down there. So it looks like the cause of our bleeding in our patient, our mystery vitreous hemorrhage, is a vitreous separation. I know the vitreous has separated, because the blood was not attached at the optic nerve in the vitreous. So here’s my cautery tip. I’m gonna test it up here in the vitreous, make sure I’ve got it connected and working. And I do. We want to be careful and not make trauma to the retina here. We want to be above the retina, on the tear site. Are we in view there, on the TV screen? Thank you. And we’re gonna come down and cauterize these blood vessels. That’s all we need to do. I’m gonna come back and check that with the vitrector a little bit. And make sure it’s a torn vessel and not a small retinal tear under there too. Normally if the vitreous pulls away and it’s strong enough to tear a vessel, quite often it will tear right through the retina too. So we’re gonna come down here and I can see a little bit of bleeding at this site. I can see a little vitreous detachment. And you can see a little bleeding on the screen there too. So that red coming up. So my concern is there’s a small tear here too. We’re gonna go ahead and put some laser around that, Mike. Okay? Let me switch hands here. I’m gonna go back to the right side. I’m right-handed. And it’s a little more comfortable for me to use my right hand if I’m doing close retinal work. I can go back and forth, but again, I can say, for anyone starting out, try to use your dominant hand, if at all possible, for most of the maneuvers. It’s very useful to have a good offhand, especially with the vitrector or the endolaser probe, but… (cell phone ringing) I did not silence my cell phone. That’s mine that’s beeping. We didn’t request that. I should put that in the slide set. Silence cell phones, just like in theaters. Okay. So what’s satisfying about the case here is that not only did we get the hemorrhage out — we were able to confirm and find a source of the bleeding. And then treat that source of bleeding. This is the endolaser probe. I like an adjustable endolaser probe, so if I move a slide on the probe handle, the tip will come out and bend, and I can direct it more easily towards the location I want. It’s very useful especially in phakic patients. You can just see the tear site there. See the little round piece in the middle? I’m kind of going around it. You can also use the laser as a cautery. A soft tip? Why don’t you get one? Take the laser and stand by. So we’re doing just fine. I’ll use one more instrument here to show you something. We’re gonna zoom in a little bit more. I’m just gonna come down here and amputate the vessel and see if there’s any more active bleeding. If there is, we can certainly address it. You can see this vessel is torn, coming right over the tear site in here. Small tear. But no detachment, thankfully. Let’s take the soft tip. So soft tip aspiration is kind of like the old flute needle. Which was passive. This is just active aspiration. And you can use it to… We can use it to aspirate a little bit of blood or be near the retina. What’s nice about the soft tip is you can get closer to the retina with less concern of trauma. So we can see if anything else is gonna pull up down here or bleed, and we’re fine. We can also use the soft tip to confirm there’s a vitreous separation by moving it over the optic nerve a little bit and seeing if any vitreous engages. The tip will bend. That looks really good. So let’s look with scleral depression. At the end of every case, I like to do scleral depression to check for any retinal tears. And we’re gonna do that myself with the light pipe in one hand and the scleral depressor on the outside of the eye on the other. I don’t know if we got this in view or not. But you can see I’m pressing in one of the cannulas right there. That’s the working cannula. And right here is the infusion cannula. And I’m looking at that peripheral retina for any more tear sites. Being a high myope with one tear, there’s quite possibly more tears. The view is a little obscured by the vitreous hemorrhage down below, but I can just get out to the peripheral retina far enough to be comfortable there’s no tear there. I’m gonna come back around to the top. And look here. I do think this is a critical part of the case, so for those starting out, I think if you can do the surgery and leave the operating room with no new tears created, you’ll be much happier in the postop checks, seeing that the retina is completely attached and healing nicely. Here’s my depressor. I just use one of these. Like this, during… What you’re seeing through the wide field visualization system… Is this pressing in the eye from the opposite side. Go ahead, Mike. I will say that one thing you always want to be careful with, again, is the light. You don’t want to be causing trauma with the light probe, either in the lens or against the retina. So I tend to keep the light pretty far back. You can see it right here. I don’t hold it across the eye. Get a little wider field of view with the light, a wider cast of light, by holding the light pipe further back. Again, we’re just checking the periphery for any other tears. And we don’t see any. So this is excellent. So the next choice is: What are we gonna leave her eye filled with? Balanced salt solution, gases, oils? In a case like this, we’re gonna leave it just with balanced salt solution. There was no retinal detachment, the retina was flat, there was a tiny tear, and that laser alone should heal it. So now we come to the conclusion of the case. We’re gonna take out the cannulas. I’ll typically hold the cannula. You can see the little wound will. You can see the wound there. I’ll press the wound down a little bit, not enough to make it gap, but over the tunnel. So I’ll press there. We can see — no leak. No conjunctival ballooning up. No fluid pouring out of the eye. We’ll do the same thing here. You can see the conj comes up a little bit there at the start. We’re gonna press that wound down too. Again, just over the top of the tunnel. And again, no leak. And then lastly, we’re gonna take out the infusion cannula. You can see the little hole there. And brush the conjunctiva back over place. And again, press over the wound a little bit. Over the tunnel. So you don’t gape the wound. The incision is right here. Do you have the smaller forceps? Maybe this will show a little better what I’m doing. The incision is right here. But the wound went this way, so I press over the top of the tunnel. What I call the cannula path. That kind of collapsed. And then I’ll check the eye with my finger or an applaner, and it looks good. I think we’re fine. We’ll remove the lid speculum. Sometimes I want the eye a little bit further. We’ll inject balanced salt solution into the eye with a needle, but I think that was adequate. I want to take a few questions. During the case… I kind of forgot about that a little bit. Some questions were sent in earlier. But you can go ahead.

>> Any tips to avoid recurrent diabetic vitreous hemorrhage?

DR MILLER: I think the best way to avoid recurrent diabetic vitreous hemorrhage is cauterization during the surgery. I’ve found the most useful technique has been to use — now, Mike is gonna finish the case back here. Pulling the drapes off. He’s gonna put a patch on the eye, with some antibiotic, and a shield. And do all the postop instructions and so on. But to get back to the question about avoiding postop diabetic vitreous hemorrhage, I think your best move is to place Avastin, if you can, before the surgery. If you can place an injection of anti-VEGF, whatever it is, Avastin, Eylea, or Lucentis, into the eye, I think your chance of intraoperative bleeding is a lot lower, and postoperative bleeding. So good cautery, photocoagulation, and Avastin preoperatively are probably the best ways to avoid postoperative hemorrhage.

>> (inaudible)

DR MILLER: I think the most common challenge is orientation in the eye and controlling the instruments with your hands. You want to try and make the instruments move around and not flex. So you want to be able to move the instrument, to pivot the instrument, at the cannula site. So if you can make it pivot at the cannula site, as opposed to pushing the whole eye back and forth, with the cannula, you’ll save a lot of instrument flexing and bending and a lot of frustration. So I think you want to keep your view all the time. And keep your orientation all the time, and try to use those pivot points, the natural pivot points being at the wound sites.

>> How often is this type of surgery done to remove floaters?

DR MILLER: So floater surgery is becoming more common. We’re seeing more of that being performed. I would say it’s not common. You know, the number of patients who come in complaining of floaters — maybe for every 20 patients that complain of floaters, one of them may be complaining enough where they’re gonna go to a retinal surgeon and then talk to the retinal surgeon, and then maybe only 1 in 20 of those actually is bad enough to follow through getting a vitrectomy surgery. So I still consider that a rare indication, but it is one that we almost never considered 10 or 20 years ago, and it’s definitely becoming more common, but still rare.

>> (inaudible)

DR MILLER: Right, so… We can use laser instead of cautery, and I think that works for small hemorrhages. So if you’re doing a diabetic case, and you’ve got small little bleeding, dot and blot bleeding, as you sever some neovascularization, I think endolaser can work very well. It definitely gets a little more difficult to get enough power on a large neovascular vessel. That’s when I still have to resort to cautery. I’ve tried for years just to use laser and not to have to get out the cautery, but there are still those cases — in some parts of the world where you’re doing severe diabetic cases and there’s large neovascular vessels, it’s gonna be hard to cauterize using just laser. You have to get out the endocautery. So my equipment — I was using the Dutch Ophthalmic EVA vitrectomy system. I was using an Eibos viewing system, mounted on the microscope. I’ve used other systems over the years, including the BIOM, but this is my preference. They can all work. There are some nice features like this one, like it doesn’t need an inverting system, and so on. It’s less moving parts. Holds up very well. Very robust.

>> (inaudible)

DR MILLER: Yeah, I think the flute needle can work very well. The soft tip extrusion cannula and active aspiration is just another thing that’s advanced over the last few years. I used to only use a flute needle. You know, going back 5, 10 years ago, for the first 10, 15 years of my practice, so I think that’s really equivalent. You can do very well with either one. Not a problem. I think we should probably just cut back to the questions, and my didactic. And we can always come back and try and answer some of those questions at the end, if there’s a little more time. I’m happy to answer those. So I want to do a couple of the review questions. First of all, I wanted to discuss the case a little bit. So she was a high myope, had a vitreous separation, or a vitreous detachment, then developed a small retinal tear, and an avulsed retinal vessel that was still actively bleeding once we disturbed the vitreous. So it was a nice case to see us use multiple instruments, and I think she’ll notice a rapid improvement. And in this particular case, you prevented the formation of a retinal detachment. If we had waited indefinitely for that vitreous hemorrhage to clear, you could wait another month or two months, and that hemorrhage could have cleared enough to where she regained most of her sight, she would have had a significant risk of developing a retinal detachment, which would have been a riskier surgery and probably a reduced visual outcome. So some review questions. Review question number one: What is a possible risk to vitrectomy surgery? A is endophthalmitis, B is retinal detachment, C is cataract, D is choroidal hemorrhage, and E is all of the above. So we’ll give you a couple seconds here, and then we’ll review that with you. And we’ll also try and go back and answer a couple questions if we get a moment. Okay. So all of the above. And the vast majority of you got that right. You know, all these are bad things that can happen. Some worse than others. I consider endophthalmitis the worst complication, but all these can happen during vitrectomy surgery. The next question. What are possible causes of vitreous hemorrhage? A is proliferative diabetic retinopathy, B is retinal vein occlusion, C is retinal vasculitis, D is retinal tear or detachment, and E is all of the above. I’ll give you some time to think about that a little bit. This case we just did is very much in line with this particular question. So hopefully you’re able to learn something and hear me during the case, as I was doing the surgery. I’m covering the microphone, sorry. Thank you. Yeah. So there we go. So most people got this right again. All of the above. Again, any type of ischemic disease — so that covers proliferative diabetic retinopathy, retinal vein occlusion, all of these. What is the best way to prevent postop retinal detachment? A, use a wide field viewing device, B, ophthalmoscopy with scleral depression at the end of every case, C, low aspiration/vacuum during vitrectomy, and D, avoid the vitreous base with the cutter. Again, the question: What is the best way to avoid retinal detachment? You could argue that all of those have some role in avoiding retinal detachment. I think you noticed in my case I was not doing a vitreous base dissection. We did not do shaving of the vitreous base. I think the number of cases that require shaving are actually quite rare and low in number. And I think most people are just gonna get in trouble with putting the vitrector in the vitreous base, unless you really have to be there. I think you’re better off avoiding those areas. So I’ll give you a little time to pick your answer. Most of you got that right. Ophthalmoscopy with scleral depression at the end of every case. A few people picked the vitreous base. That’s what I was talking about. I kind of misled you a little bit. But if you can find the tears at the end of your case and repair those in the operating room, that will save you a lot of postoperative problems. And the last question today: What are the possible causes of worsening elevation of retinal during vitrectomy? I didn’t cover this in my lecture today, but let’s see if you can figure this out. While you’re doing the vitrectomy, if you see the retina coming towards you during the case. Number one, choroidal hemorrhage, two, misplacement of the infusion cannula, hypotony from low infusion, retinal detachment, or all of the above. We’ll give you a few seconds to try and figure that out. So at the start of my case, you did not see me check for the infusion cannula placement. Many, many surgeons will do that. I kind of go by the feel when I push through the cannula, and I know by the start of the case very quickly. But let’s see what we’ve got here. There you go, very good. All of the above. So if you see the retina coming towards you, one possibility is choroidal hemorrhage. It’s uncommon, but it can happen. If you’re in the suprachoroidal space, you can cause choroidal effusion. You can see the eye wall kind of unfold and come towards you as the pressure in the drops, and of course retinal detachment. I’m happy to answer a couple more questions. I think we have a little bit of time, Jonathan, if that’s okay. We can probably answer a few more. Thanks. Yeah, if the instruments are jamming in the cannula, there may be some burrs or improper manufacturing process where the instruments got a little — or it can be debris, if you’re using a lot of reusable instruments. Sometimes there will be dried debris on the shaft of the instruments. Once they’re machine-made and they’ve worked once, they should continue to work. So I recommend in your cleaning and processing to make sure all debris gets off the cannula before it gets cooked in the steamers, because sometimes it can kind of bake on. So make sure your instruments are nice and clean. What is the best way to practice dexterity of one’s non-dominant hand? That’s a good question. It definitely helps in vitrectomy surgery — this is not the basics. This is kind of advanced vitrectomy surgery — but I think it does help to have a good offhand. And I myself, I used to practice with my left hand at a microscope at home, and at work. Picking things up with forceps, moving things around with retinal forceps. So I would work under a microscope, using my left hand, my non-dominant hand, to perform maneuvers, even if it was just moving around a piece of thread on a desktop. And just by repeating those actions, it gets easier and easier to use your non-dominant hand. It’s very useful for the vitrector and for the endolaser probe in particular. You don’t necessarily have to peel with your non-dominant hand, but even that can be useful in some cases. Someone wrote in about not double checking the placement of my infusion cannula. I would not recommend that for beginning surgeons. I think beginning surgeons probably should check the placement of the infusion cannula. I think that’s a very good point, made by the person who wrote that question in. I think that you don’t want to start out having troubles, like not having the infusion cannula in the right location. And the best way to confirm it, I still feel, is to look off to the side. So using your light pipe, shining into the eye, and looking outside the microscope, out through the scope, by looking outside the scope. Some people grab the infusion cannula and try to press it in, to see it show up through the microscope view. I’m more comfortable glancing outside the microscope view and looking to the side. Well, thank you very much, everyone, for your time this morning. I hope this was useful to some of you. And I hope to do this again at some point, and we’ll see you then. Thanks for your attendance this morning.

>> Thank you very much, Dr. Miller. Well done.

DR MILLER: Thank you.