Lecture: The Open Globe

This live webinar will introduce the classification of ocular trauma, define the “Open Globe”, review the epidemiology of posterior segment trauma, and reiterate important surgical anatomy of the eye. The evaluation of the traumatized patient with an open globe and the ophthalmic surgical goals for therapy will be emphasized to include eye wall closure from the cornea to the posterior sclera. Special considerations will be addressed, including primary enucleation, post traumatic endophthalmitis, prophylactic scleral buckling, timing of vitreoretinal surgical intervention, and the management of intraocular foreign bodies (IOFB’s) of various types. A variety of surgical case examples will be offered. Finally, critical ‘take home points” will be reviewed.

Lecturer: Rosalind A. Stevens, MD. MPH, Professor of Surgery Emerita, Geisel School of Medicine at Dartmouth, New Hampshire, USA

Transcript

DR STEVENS: Good morning. I’m quite happy to be able to meet with all of you today. I am a vitreoretinal surgeon who has been volunteering with Orbis for the past 20 years. It seems like a short period of time to me, but in looking at the registration list for this presentation today, I see there are several familiar faces of people I’ve worked with in the past, so that’s heartwarming, to say the least. We do have a list of questions we’ll try to address either during the talk or at the conclusion of the talk. If not, I’m sure you can email questions subsequently as well. Our topic for today is the open globe. What I wanted to discuss with you this morning is our approach to the open globe. And what we’ll do first is to find the open globe. The subset of traumatized patients that we’re speaking about. And then we’ll go through therapy and some of the special considerations that one needs to have in mind to manage these patients. This particular patient is one of our patients, seen here in New Hampshire, in the northern United States, who was actually brought into the hospital by helicopter. And although that seems dramatic, I think it illustrates how nervous referral personnel, referral physicians, ambulance drivers, et cetera, are, when they see an injured globe. I’m sure you’ve seen that in your operating rooms. It may be difficult to get some nurses to work with you, doing eye surgery, and part of that is because of an innate fear of the delicate nature of the eye. So our learning objectives for today are to recall that we should plan emergent exploration of a suspected globe opening, review the eye wall closure techniques that are important, recall the 8.0-9.0-10.0 rule, and think endophthalmitis. We have some questions that I’d like to ask you to answer in your own mind. We’ll have a poll. But we won’t give the correct answers until later in the talk. Just so we can measure how much you’re able to absorb, I would say. The sclera is thinnest at: A, the limbus, B, the equator, C, the rectus insertions, or D, the macula. And we’ll give you about 30 seconds to vote. So we’ll review the answer later, but I would say the vast majority of you picked the rectus insertions. Siderosis refers to the effect of which type of intraocular foreign body? A, copper, B, glass, C, iron, and D, aluminum? And I would say the majority, again, chose iron. And the last question. What is the most severe form of traumatic endophthalmitis? Is it A, staph aureus, B, pseudomonas, C, bacillus cereus, or D, A and B? And about half of you picked A and B, staph aureus and pseudomonas. I’d like to review the classification of ocular trauma, because the terminology that we use to describe eye injury has been rather muddled over the past 30 to 40 years. So we’ve all agreed on a standard form of nomenclature, so that all physicians and surgeons can speak about the same type of injury, one to another, and also use the same definitions in their research. This is one ocular trauma book I’d like to recommend, because it’s quite easy to understand, and also touches on the main themes of ocular trauma, with multiple little sections of pearls that are helpful in management. When we review an eye trauma case, we can define the trauma by the type of trauma, its grade or level of vision, whether or not an afferent pupillary defect is present, and the extent or zone of the eye that is involved. There are closed globe injuries, which we’re not going to address today, essentially bruises or blunt force injuries to the eye that do not open the eye wall. And those may be contusions or partial thickness lamellar lacerations or superficial foreign bodies that do not actually enter the globe. Today we’re going to be talking about an open globe, or full thickness subset of injuries, and these may be due to blunt trauma or rupture of some section of the eye, or they may be sharp injuries, like a surgical wound, for example, and these lacerating injuries may be penetrating, and penetrating means one entry into the eye. They may be perforating, which means two or more entries. And this is typically seen where a foreign body enters the eye and then exits, so this is a perforating injury. And may often be associated with an intraocular foreign body. Here is an example of an eye rupture. You can see that there’s been blunt trauma to the eye, and the eye has ruptured along a weak area. I often tell students or referring doctors when they’re calling from the emergency room that if you see a chocolate colored dark or dirty appearance to the wound, that’s typically choroid or choroidal pigment, and may even be the iris root. And that helps them identify whether or not there is an open globe. We can classify these injuries by grade or visual acuity, and they may be segregated into four categories, greater than or equal to 20/40, 20/50 to 20/100, 19/100 to 5/200, or 4/200 to light perception. In other words, quite good to quite poor. We may also segregate them by whether or not there is an afferent pupillary defect present. On the cartoon on your left, you see the light is being shown into the right eye, and the injured eye on the left does not really respond. If the light is shown into the left eye and the right eye responds, that tells you that the neural connections from the injured eye are intact. So there’s no afferent pupillary defect. But if you shine the light into the eye, and in fact the fellow eye dilates or is non-responsive to the light, this is a positive afferent pupillary defect, and implies a defect in the connection of the left eye. So it’s a very gross test of functionality. And lastly, we may classify the type of injury by zone. Zone one is defined as the cornea and the limbus. So the area of the cornea out to the ocular limbus. Secondly, zone two is the limbus to 5 millimeters posterior to the sclera. And thirdly, posterior from 5 millimeters from the limbus to the posterior segment. And the reason for this zone definition is we’re really trying to consistently identify where the interior of the eye is free of retina, and where the retina begins. We know that the retina begins at the level of the insertion of the rectus muscles, so that’s one way we can tell where there’s retinal tissue. And this will become important when we have wounds involving this area, because it helps with our referral process, helps us know what to prepare for, and whether to expect retinal injury. The ocular trauma score system is something that’s used primarily in research situations, but can also be used to help you estimate what the final visual acuity or predicted vision outcome is going to be in an injured eye. This is an example of the OTS calculation. What we do is determine the initial visual acuity, so let’s say, in this case, the vision at the time of presentation is light perception to hand motion. And then we add up the other negative factors, which are impacting this globe. So, for example, if we have a globe rupture, that’s -23 points, with endophthalmitis, that’s -17 points. So 23 and 17 is 40. If we subtract 40 from 70, we end up with a score of 30 points, which we then flip the card over, and look up our raw score. So a raw score of 30 would say that the chance of achieving greater than 20/40 vision is about 1%. I will say when I’ve used this calculation, I tend to be quite a bit more optimistic, and I think that is borne out in the literature, where a variety of groups may underestimate the potential visual acuity. And that is because as our technology improves, we’re better and better at repairing these globes. There are both United States and world eye injury registries, and these you can look up online or during your research, prospective studies that you wish to do. It’s good to be using the same language across organizations. I wanted to touch on the epidemiology of posterior segment trauma. In the United States, we know that the injury rate in the posterior segment group is about 29 per 100,000. The male to female ratio is 3 to 1, and that’s true across all countries, really. Of all those injuries, a total of 40,000 will be quite severe. So at least in the US, there are at least a million trauma patients who have a significant impairment, and that implies that there’s quite a secondary economic effect. When we look at who really is the injured party, most of these individuals will be male. A lot of them are construction workers. They’re usually fairly young, in the 25 to 35 age range. They may tend to be poorly educated. In the US, a lot of them are associated with dangerous behaviors, such as drugs or some situation where they don’t have a good understanding or characterization of the risks to their eyes are in, depending on the actions that they’re taking. A common place of injury is the workplace. I know in many developing countries, there are huge construction projects going on, without an effort to prevent this type of injury. Injuries in the domestic section are rising, and auto accidents constitute 11 to 17%. And that depends on how many cars are in your country and what the rules are for driving. The source of trauma may be blunt, 31% to 45% of the time, which implies that the rest of the time, it’s sharp or associated with a lacerating intraocular foreign body. So that’s quite severe. In people under three years old, it’s retinoblastoma. This is a preventable societal burden, and prevention strategies at the governmental level are critical to helping reduce the burden of ocular trauma. And this would be all kinds of preventative strategies mandated by the government, such as safety glasses, et cetera. It’s helpful to remind ourselves of the surgical anatomy. I know you’re all familiar with the anatomy of the eye. But it’s important to recall the ora serrata, which is this orange demarcation here, is adjacent to the insertion of the rectus muscles. When we look at the area of the eye which is most prone to rupture, you can see that the area under the rectus muscles is 0.3 millimeters thick. Whereas the equator of the eye is 0.6 millimeters, the limbus is 0.8 millimeters, and the posterior pole is 1 millimeter thick. When we evaluate a patient with an open globe, the history is critical, because they will often give a history of some type of force, such as a hammer or metal on metal, and these are excellent clues to determine whether or not there’s a piece of metal in the eye that must be removed. The level of vision is critical. And that’s because not only does it predict the trauma, the trauma score outcome, but it gives you a general idea of how badly the eye is injured. And finally, there should be a dilated eye exam in both eyes, because even if one eye appears to be the injured eye, the fellow eye may also be injured. So you need to do your standard exam without deviation. Here’s an example. This woman is in the operating room, ready for surgical repair. And you can see, when you look at her, her left eye appears to be the one that’s injured. It’s all bruised and swollen. But when we examine her eyes, you can see that the right eye is the one that has the rupture at the limbus, and you can see the dirty dirt-like choroidal tissue here. Whereas the left eye looks pretty nice. It’s got a formed cornea. Indirect ophthalmoscopy shows the interior of the globe to be normal. Finally, when you have an open globe, and you’re preparing to do surgery, which is the primary intervention that you’re contemplating, a patient needs to be NPO, as soon as you see them. The eye should be shielded. And I know it’s frequent that one is in an emergency room and there’s no eye shield to be found. You can make an eye shield with a coffee cup, for example. You need to have something over the eye, first of all to highlight to the nursing staff and other physicians that the eye is in a precarious state, and to protect it until you can move into the operating room. A tetanus shot is given. Some of these people will feel quite nauseated, so an antiemetic should be ready. As far as further investigation, x-rays of the eye, CT scans, B scans, MRI scans, all of this can be done after the primary repair of the globe. So your first effort is to repair the globe and stabilize it, and you can then do these other tests to determine: Is there a foreign body, for example, what does the interior of the eye look like? Here’s the patient that we saw brought in by helicopter, with a roofing nail through the eye. He was referred in with some x-rays. And you can see on the x-rays we can appreciate the full length of the foreign body. He also was referred with a B scan, and you can see the inside of the eye is fairly clear. So in this case, the surgeon felt fairly confident in just removing this, as the inner part, intravitreal area with the foreign body was not involved. It may look like the globe is ruptured, but in fact, it’s just displaced. And we see in this area the forester who was out looking up at a tree and removing the branches was impaled with a stick. This lucent area. But the globe itself was not injured. As we start our evaluation and management, you move from the external eye internally. So in this case, the patient looks pretty normal. His associate at work was using a nail gun, and this gentleman bent over to tie his shoes. When he did, the nail gun went off, and the nail went through his upper brow area here. But when you pull the lid up, you can see a bead of vitreous here. So it impaled not only the lid, but the superior sclera. And the fundus — you can see there’s an area of folded retina inferiorly, with an exit wound inferonasally. And the area of retinal detachment is identified because you can see this sort of fold with the grayish discoloration of the retina. You’ll note that we did our indirect ophthalmoscope exam early on, when we had an opportunity, because sometimes vitreous hemorrhage and fibrin formation will obscure your view. So one of the first things you want to do is try to get a picture, an examination, of the posterior segment, before the view is clouded. As in this case, where the lens has become opaque. At the slit lamp, if there’s some question about whether there’s a corneal laceration, you can do a Seidel test, the same test you would do for evaluating a glaucoma filtering bleb. Fluorescein on a strip is dark orange when it’s concentrated, and when it’s applied to the cornea, if there’s an area of leakage, the dye will dilute and become bright green. So that is known as a positive Seidel test. When you’re looking at the anterior segment, you can see that there may be suspicious areas, although you don’t actually see a perforation. Sometimes the pupil will be peaked toward an entry wound, or there may be an area of lens rupture. In this case, the ocular media were clear, so one could see this metallic foreign body embedded in the retina, prior to the time that the blood begins to diffuse and obscure the view. Finally, many people will recommend checking the intraocular pressure, and I think that that is really not helpful. If you are pressing on the eye, and you’re either inexperienced or unaware of what the range of pathology may be, knowing that the intraocular pressure is normal does not help you, because you may have a posterior rupture with a normal or even an elevated pressure. If the pressure is low, that doesn’t necessarily prove that there’s a rupture. So I would just prefer to defer that, until a later time. The B scan is something that also may involve gentle pressure on the eye and does not really change your management with regard to primary repair. The general rule is: If the B scan is fairly disorganized and the interior of the eye is fairly disorganized, and you cannot approach fixing this problem until you have a stable, secure primary globe repair. In this case, you can see the patient had a pry bar go through the anterior segment. The iris is missing. The lens is missing. And the pry bar caused incarceration of the retina, posteriorly. So our surgical goal is emergent eye wall closure. I believe you should repair an open eye as quickly as you can, and in a general hospital, that may mean when can you get into the operating room. But you need to make the other doctors on the list or anesthesia aware that this is an ophthalmic emergency. An eye wall should be closed prior to doing an elective appendix, for example. So in many cases, this will have to be done with general anesthesia, or a laryngeal mask. We may repair the anterior segment with a microscope, but you really cannot see, posterior to the limbus, well with a microscope. So as you move posteriorly on the eye, you may need to switch to loupes, to visualize what you’re looking at, or your own glasses correction may be sufficient as well. You should avoid pressure on the globe, and perform a careful tissue dissection. Closure of the primary eye wall is the key to management here, and occasionally you’ll have to manage the lens as well. Most of the time, you just want to close the eye, even if the eye seems ruptured. But if there is lens material coming out through the wound, you may need to clean that up as well, before repairing the cornea. When we do the globe repair, it may be difficult in the middle of the night to remember which sutures you should use. I try to remember 8.0, 9.0, 10.0. The cornea requires a fine suture, so 10-0 nylon with a spatulated needle is terrific. At the limbus, 9-0 nylon with a spatulated needle is fine. For the anterior sclera, 8-0, either nylon, or some people will use silk, because it’s a bit more inflammatory and helps the wound close faster. The posterior sclera may be so distorted, and it’s fairly thick, as you move very posterior, so you may even need to use 7-0 suture, as you move posteriorly, just to get enough force to close the eye. For doing corneal laceration repair, minor open globe injuries may be self-sealing. And in that situation, they can be treated with a contact lens. If the wound, though, is open, what one wishes to do is reposit any iris tissue, and this can be done by injecting viscoelastic into the anterior chamber, to help encourage the iris back into the eye, or to protect the corneal wound from suturing. That’s quite helpful also in that it helps control minor bleeding. Following that, you oppose the edges. And this can be done by finding the landmarks, such as the limbus, and then dividing the wound in half. And then half again. Now, what I will say is that the exception to this rule is that if you’re working, say, from the limbus toward the center of the cornea, you may wish to start at the corneal edge, and work in. The main thing is to keep the two margins opposed to each other, so that they come out even or symmetrical, so to speak. This is an eye bank eye, showing a laceration from the limbus, and you can see here it has kind of an S shape. So there’s a suture placed at the limbus to be sure that matches, and through the irregular middle of the wound, staying perpendicular to the wound, to oppose the main portions. And following that, the remainder of the wound can be closed. Here’s another example, coming from the limbus into the center. You try to avoid the very central visual axis, if you can. I should note that when you’re placing these sutures, by the time you finish, there will often be a few of these sutures that are loose. So I want you to know that that’s a normal situation. Once you have stabilized the eye, you can go back and replace those loose sutures. Finally, you want to do your best to bury these knots, because these will be quite irritating. So you want to rotate the sutures, so that the knots are buried. In the cornea or the corneal-scleral limbus. When we talk about the length and spacing, of the sutures, you can see in this diagram the longer the suture, the broader the zone of compression. So if you have long sutures, you’re more able to achieve a watertight wound. If you have multiple short sutures, you’ll have a zone in between that doesn’t really have a compression on it, so it will leak. So you want to make an effort to have a long suture that overlaps the zone of compression of the next suture. So here we have two long sutures. They overlap. They’re both longer than this distance, and that can help you in trying to make the wound watertight. When you speak to corneal surgeons, there can be some disagreement in repair of the cornea. 90% depth, when you place your sutures, versus full thickness depth. The goal is to try to reoppose the two portions of the cornea, and not have a ridge left over. So I personally try for 90% to 95% depth, because then I feel that I have not created another channel into the anterior chamber, which might potentially lead to endophthalmitis. Here’s an open wound. Unsutured laceration, which may be kind of a valve, allowing fluid into the eye, whereas when it’s sutured, that section of the cornea flattened. And there are corneal surgeons who try to do refractive care, in that they put longer sutures at the limbus, and shorter as they move to the central cornea, to give a better refractive outcome. Here we see a corneal laceration, and you can see the matching corneal map, with flattening in the area of the suture line. Here we have a shelved wound. You can see that the wound goes in, and the key is to try to get this to oppose itself symmetrically. So you want to be able to imagine that you’re closing the posterior area of the cornea well. You don’t want to leave it open like this. Or when you see histopathology of injured eyes, subsequently, when they’re removed, this tissue override leads to corneal failure and opacification of the area that’s been repaired. Corneal suturing. Here is an eye with a positive Seidel test. Bright green fluorescein dye. And here it is after suture placement. Perpendicular to the wound. And as long as possible. Now, you may see eyes that have stellate wounds. A stellate wound is a round hole in the front of the eye that may have many branches. You may want to close the branches, and then try to make the center portion water tight, with a lasso or complex figure of eight suturing. As a last resort, we may put glue over the area. And you see here sometimes you just have to kind of make up what kind of a suture you’re going to evolve with. But the middle part here is the area where we’re still having some leakage. So you remove the epithelium without cutting the sutures. And then dry the area carefully, and put a tiny droplet of dental glue on the surface. That usually will spread out and stick for a couple of days, and you can aid that by applying a contact lens. I think one of the questions submitted was what to do with iris prolapse. And you can see here this prolapsing iris. This looks quite healthy, so I would take Viscoat, and gently encourage this back into the anterior chamber, and then repair the cornea. Now, if this tissue has been exposed for several days, it may be necrotic. If it obviously cannot be salvaged, you should cut it off. But that is something that will require a secondary repair of the iris, to make a reasonable pupil, for example. So I would go out of my way to try to hydrate this first with balanced salt solution, and then reposit it with Viscoat. You can approach tissue that’s incarcerated in the wound by swiping it with an instrument. And then placing Viscoat to protect the posterior cornea. As we move posteriorly on the eye, conjunctival peritomy is performed, to visualize the limbus, and that so-called zone 2 area. You perform your conjunctival peritomy for visualization, and then you approximate the limbal areas. So this I think is pretty obvious. This corner goes here, this corner goes here, and this corner goes here. So you suture that so that you feel confident that you’re putting the eye back together correctly. This particular picture shows an eye that has been prepared for surgery by slinging the muscles, as we would to do a scleral buckle, for example. And that is something that you can do gently, if you need to explore further back toward the equator, for example. Here is the appearance of the rectus muscle being pulled out of the way. And you would want to do this quite gently, because the thin area of the sclera behind the iris here is the area of potential likely rupture. And if that were to be the case, and I saw a rupture here, I would suture one side, and then move the muscle to the other side without disinserting it, and suture the other side. You can then move back to the equator. I think people who do scleral buckle surgery or strabismus surgery would be comfortable with this. This is where you have to forsake your microscope and use loupes or your own refractive correction. Because the microscope just doesn’t tilt well enough to see this area easily. Then we want to do a watertight closure. Here the cornea and limbus has been opposed. But these sutures are still pretty short. So once we have things in place, we would place longer sutures, and then remove these. Here’s an example of a watertight closure. You see how close these sutures had to be, to make this wound watertight. These happened to be 8-0 silk, so you can see them easily in the subconjunctival space. Lastly, you want to measure the wound. And put a sketch in the chart. Because the physician following you, for example, a referral physician, will want to know: Is this 4 millimeters, or is it 9 millimeters? In this case, this goes back 9 millimeters, so we know there’s very likely a retinal break or potential retinal involvement in this area. Now, one of the things that has been recommended is muscle disinsertion. I think that is only very rarely necessary. The muscle can be recognized because it has that celery-like striated appearance. And if you did have to take a muscle off, for example, because there’s a huge laceration that you just can’t approach otherwise, you would put the muscle on 6-0 suture, just as you would for adjustable muscle surgery. Remove the muscle, and then replace it by suturing through the muscle insertion, to place the muscle back in the eye in the same position. If you’re at the equator, you may not be able to reach further back. So what you do is start suturing in the anterior portion of the wound toward the posterior pole, much like closing a zipper, although you may not be able to close the posterior portion of the wound. Here we demonstrate this approach to perpendicular suture placement. You can tie a surgeon’s knot, three throws, one throw, one throw, to secure the wound. And you can see as we move posteriorly, this entire wound was able to be closed, because it’s an eye bank eye. But sometimes that’s not the case. You may get as far back as you can, and then the last little bit you simply cannot reach without being at risk of extrusion of tissue. So you leave that alone, and that will self-seal and granulate in, typically within 48 to 72 hours. So you don’t stitch it if it’s a posterior perforation. Here’s the optic nerve and here’s the nail coming through the back of the eye. So you remove the nail, but you leave this alone. Special considerations we have to keep in mind. It’s very unlikely that you’ll have to do a primary enucleation. If there’s just nothing to fix, you might. But it’s better to sew up what you can, even if you can tell that you don’t have a chance of repairing the eye, because psychologically, it takes the patients a few days to adjust to the fact that they’re gonna lose the eye. And after you’ve had the discussion with them, then it’s better to go back and enucleate the eye, if you feel that that is indicated. This is another example. This is a 30-year-old male who had a mental disability. He had had congenital cataracts as a child and secondary implants with a neurodegenerative disease. He came in with 20/50 acuity in one eye and no light perception in this eye. You can see that technically this is an open globe. Here is his secondary implant, and you see the foot plate of his intraocular lens bridging over the limbus here, so the globe is open, but there’s no view of the posterior pole, because of the blood, et cetera. So in this case, we’re always taught in residency to do a B scan, because you just never know what you will find, even though we typically don’t find anything. However, when we did this B scan, you can see there’s a V shaped retinal detachment, but there’s also a mushroom-shaped unknown lesion here. So if we’re gonna call this mushroom-shaped, that in your mind should take you to a potential diagnosis. When we see a mushroom shape on B scan, we think of malignant melanoma. And surely he did have posterior segment choroidal malignant melanoma. And here’s the anterior chamber intraocular lens. So as you can see, this eye was then enucleated. Post-traumatic endophthalmitis is one of the most feared complications of globe trauma. It may occur anywhere from 2% to 7% of normal ruptured globes, but if the rupture is complicated by a ruptured lens, intraocular foreign bodies, a dirty wound, it may be as high or higher than 30% risk. How do we determine if there is endophthalmitis? My rule is: If I even think about endophthalmitis, I will treat for it. Very aggressively. If you see intraocular inflammation with a hypopyon, if there’s retinal periphlebitis beginning, if you can see your intraocular foreign body, and it’s beginning to develop exudate around the margin of the intraocular foreign body, you should treat. I would recommend prophylactic intravitreal antibiotics, and this depends on your skill level. You certainly should do the primary repair of the eye first. And once the globe pressure has been normalized, prophylactic intravitreal antibiotics may be given. And these are given in cases with periphlebitis, purulent foreign bodies, soil-related injuries in a rural setting, or delayed primary closure. If the eye has been open for three or four days or longer, the risk of endophthalmitis is quite high. Now, this is an old series of the typical organisms found during a culture. In an endophthalmitis post-traumatic open globe setting. The common ones are staphylococcus, strep viridans, Gram positive rods, bacillus cereus, and you can remember that — you can think bacillus cereus is serious. This is the most serious organism, because it’s virulent. It has to… It’s very damaging to the retinal photoreceptors, and hard to salvage these eyes. You can see in this group of patients, 14 of 18 eyes had to be enucleated because of the extent of the endophthalmitis. And I mentioned earlier rural endophthalmitis is a much higher rate, 30%, than garden variety endophthalmitis. So after we form the globe, we try to do taps of the anterior and posterior chamber. If you have to choose, the vitreous tap is the more important, because it has a higher yield. You measure 4 millimeters back from the limbus, going through the pars plana. One mistake I see is people will often use a very small needle, like a 25 or a 30-gauge needle. You really will need a larger needle, such as a 20-gauge, to get a good sample of material. Otherwise, you’ll have a dry tap a significant percentage of the time. And this can be plated on glass slides for Gram stain, bacterial stain, Giemsa or calcofluor for fungus staining, and culture on the plates you have available, for both Gram positive, Gram negative, fungus, and anaerobic materials. Now, you may not have all of these materials available. So if you don’t, one other option is to place your sample in a blood culture bottle, which most laboratories, even in rapidly developing countries, will have available. Prophylactic intravitreal antibiotics are vancomycin, 1 milligram, and 0.1CCs, and this treats the Gram positive organisms, including the bacillus cereus and staph epidermidis. Cefazolin is one of the classes of drugs — you may have some similar to this in your hospital that would be effective — is 2.25 milligrams or 0.1CCs, and this is treating the Gram negative organisms. You can find the recipe for how to prepare these drops in the Wills Hospital manuals or on the internet. If you’re fortunate, your pharmacy can do it for you. If not, you have to do it, but you have to be very careful to have this correct, because you can permanently damage the retina if you’re overdosing with your antibiotics. Now, amikacin — pardon me. We don’t use very much anymore, because of the risk of retinal infarction. But if that’s the only drug you have, then it’s helpful. I would stay away from it, as best you can, unless there’s not another alternative. Ceftazidime is another alternative. 2 milligrams in 0.1 mils. We also, although there has not been a big clinical trial that approves this one way or the other, we generally give systemic antibiotics. The patient is usually in the hospital, at least in the US, for about three days. So we have the opportunity to give IV vancomycin and IV ceftazidime. The patient is then discharged home, and at that point, we switch to oral ciprofloxacin. One could begin with oral ciprofloxacin, but as the antibiotic sensitivity of organisms change, you would have to determine from your local infectious disease physicians if that’s still appropriate in your setting. In some cases we add Decadron 0.4 milligrams if there’s been a lens rupture, for example, or the patient has a big fibrinoid response, such as late presentation, late repair, we’ll add Decadron as well. If you have a corneal wound, I usually use the same topical antibiotics I might use for a corneal ulcer. And I think that increases the kill rate for bacteria introduced into the anterior chamber. And those might include fortified gentamicin, 15 milligrams per mil, and fortified cefazolin, 50 milligrams per mil. And topical steroids are helpful to reduce the fibrosis formation. Subconjunctivally, gentamicin or cefazolin. Fungal infection is rare in the United States, but more common in some of the Indian literature. Up to 10 to 15% of patients will have a fungal infection, which is quite serious. And this can be treated with voriconazole, 400 milligrams orally. I wouldn’t do this unless you had a positive culture. Or a stain, proving that there’s fungus present. And intravitreal amphotericin B, 5 to 10 micrograms. Special considerations of retinal surgery: In a traumatized eye, some feel that it’s helpful to place a thin prophylactic scleral buckle. Even in the face of vitrectomy. Because it’s often very hard to treat the anterior vitreous. And if you’re forced to leave the anterior vitreous, the vitreous base, that can contract and cause more breaks to form in the postoperative period. So just a 220 band here, prior to vitrectomy, in concert with vitrectomy, may be helpful. The timing of vitreous intervention is important. We often try to delay the vitreous surgery for five days or more, to allow the posterior hyaloid to spontaneously separate from the retina, because it can be very difficult to peel vitreous, particularly admixed with blood, from the surface of the retina. One exception to this is in pediatric cases. One may need to do a core vitrectomy early, because the vitreous is so adherent to the retina. The main thing is to remove most of the vitreous scaffolding and get the antibiotics injected in that situation. There are intraocular foreign bodies that should be considered. The first is iron, which is quite inflammatory. We call that siderosis. The iron affects primarily the neuroepithelium of the eye. Which specifically targets the retinal photoreceptors and the retinal epithelium. You may see reduced ERG over time, if there is an occult foreign body, and the appearance of staining or yellowing of the lens surface. The iris may have heterochromia, brown deposits on the retina, with retinal — narrowed retinal vessels, optic disc discoloration. So this is quite an important area of therapy that you should undertake. There are many, many ways to take out these iron or other associated foreign bodies. In this particular case, the metal could be picked up with a foreign body forceps, but sometimes it’s more embedded, and it needs to be loosened or unroofed from its inflammatory covering. And then picked up with a magnet. These magnets are rare earth magnets, and they’re active for about 3 millimeters on either side of the tip of the magnet. There are some situations where the metallic foreign body is very anterior in the eye, anterior to the retina, and if they can be approached by cutting down or forming a little rent over the foreign body, they can be removed with a stronger magnet held against the tip of the sclera. Each case has to be individualized, I would say. The other metal we need to pay attention to is copper, which is very inflammatory. Copper in the eye is called chalcosis, and can cause quite an inflammatory reaction. In this situation, you can see that the copper has become deposited in the cornea. And we call this Descemet’s membrane Kaiser-Fleischer ring here. They may form what is called a sunflower cataract, and this has to be removed expediently, because of the inflammatory nature of the metal. Other metals, zinc and aluminum, are not so inflammatory. They can become encapsulated and may be observed. There are non-metallic foreign bodies such as vegetable matter or glass. These can be left in the eye and observed. We’ll repeat our poll here. The sclera is thinnest at A, the limbus, B, the equator, C, the rectus insertions, and D, the macula. Excellent, and that is the correct answer. Rectus insertions, 88%. You recall the 0.3 millimeter thickness of the sclera under the rectus muscles. Siderosis refers to what type of intraocular foreign body? Excellent. Iron. And that is correct. What is the most severe form of traumatic endophthalmitis? Yes, that’s correct. Bacillus cereus is serious. And most commonly found in rural, dirty settings. So that’s correct. I’m just gonna briefly go through a few of these cases, to give you some visual examples. We’ve already reviewed this case. And here you recall we were able to pull the nail out. So this portion was seen anteriorly in the eye, and this was in the vitreous cavity. So a vitreous tap was performed to culture the eye. And intravitreal antibiotics injected. This is a fairly complex figure of eight corneal closure, and that patient did achieve 20/40 visual acuity. This was the gentleman who had the air powered nail gun we discussed earlier, with the entry wound. Vitreous bead. The posterior perforation. You can see the striae related to the retinal detachment quite well. Watertight closure. And you can appreciate the subretinal fluid here, where the detail of the choroid is not well seen. Here the retina is attached. Here the retina is detached. This is the first vitrectomy. You can see a gas bubble was used to tamponade this area, but there’s still residual subretinal fluid here, on the surface of this scleral buckle, you can see the shoulder of the scleral buckle. And still in the postoperative period, a little residual fluid. So after observation for a while, this was not disappearing. If it doesn’t disappear, it means there’s a microbreak somewhere, that hasn’t been treated. And repeat vitrectomy with laser surrounding the posterior wound. With the sharp margin of the scleral buckle and laser scars on the surface of the buckle, which solved the problem of any residual leakage, and the retina remained reattached, with visual acuity of 20/50, one year later. This is a 63-year-old farmer, who had multiple prior chainsaw incidents. You can see the scars on his face from being injured with his chainsaw. Here’s one on his lip. And he was up on his roof, removing metal from the surface of the barn. Lacerated his cornea with the metal. You can see here the knots are buried, and they are perpendicular to the wound. Even though the eye has a primary closure, there’s still quite a bit of fibrin here, so the suspicion is: Is this inflammatory? Or is it endophthalmitis? He also had partial lens rupture. So the lens was removed. Eventually he had a secondary implant. But he also achieved excellent 20/30 visual acuity. Here’s a gentleman who states that he pulled wire out of his eye. Here’s a wire brush. Microperforation, very tiny. This was self-sealing. So he was sent for photos because of his vitreous hemorrhage, and the photographer came back and said I think I see something in the retina. He was probably waiting several hours in the retina clinic to get his photos done, and in that time, the blood cleared and you can see a posterior exit wound from the eye. Or at least a posterior penetration. So in that case, it’s really a perforation, because he had two openings in the eye. So he was treated with intravitreal antibiotics, and monitored with B scan. No surgery yet. Vitreous hemorrhage cleared over time. Didn’t completely clear by three months. He then had vitrectomy with laser and achieved 20/20 visual acuity. This one we already talked about. There’s the posterior wound. Here’s an example of a gentleman with needlenosed pliers entering the eye. And the posterior fibrotic exit wound. Again, excellent visual acuity. I’m just gonna show you two more cases. Here’s a gentleman who was hammering and pulling metal out of the floor with his hammer. You can see he was hit in the nose here, and this part of the eye became red. He came in after about three days, feeling somewhat anxious, and a little eye pain. On left gaze at the slit lamp, you can see the foreign body behind his lens, adherent to the posterior capsule of the lens. He then started to develop anterior segment cell and had intravitreal antibiotics and removing with an external magnet. Another gentleman with metal in the angle. I just wanted to show you this picture. This is a lady that fell on her rocking chair and you see this hyperemia. Any eye like this should be explored, whether it’s ruptured or not, because you simply cannot tell on clinical examination whether there’s a rupture. And then the last patient I want to share with you… Is this gentleman who was 79 when he came in on a Sunday morning with acute pain in the eye. His past history was that at age 10, he was at the beer bottle distribution plant in Ireland when the bottles blew up and struck him in the face. He spent two months in the hospital and must have had a lacerated globe which spontaneously healed. When he came to us, he had a small hypopyon, and you can see here postoperative, these areas were Seidel positive, so he had constant leakage and microperforations from the wound and was treated not only with intravitreal antibiotics and vitrectomy, but a patch graft to close the wound. So in summary, the emerge end exploration of a suspected open globe is critical. Eye walls should be closed using suture, recalling the 8-0, 9-0, 10-10 rule, and you should always think endophthalmitis, endophthalmitis, endophthalmitis, and treat aggressively. Thank you.

DR STEVENS: This first question revolves on sympathetic ophthalmia. Are you not concerned about sympathetic ophthalmia with not considering a primary evisceration in cases of extensive open globe injury with NLP? The answer is we rarely treat unless we treat with systemic steroids or systemic antiinflammatories. So removing the eye, the potential sympathetic ophthalmia, is not the first choice of therapy at this time. If it’s obvious that there are not enough pieces or parts to work with, then you could enucleate or eviscerate. In some countries I’ve worked with, it’s quite common. There were 10 or 12 people in the hospital who had their eyes eviscerated. In my experience that’s not common. It’s just a different approach to therapy. Should we apply cryo around the posterior scleral wound after suturing? The answer is no, because it’s already going to be inflamed. So it’s not recommended to apply cryo around the posterior scleral wound. Next, what to do with recurrent bleeding perioperatively in a case of traumatic hyphema, after contusion with eye hypertension? If you have so-called 8-ball hyphema with high pressure, you need to drain the anterior chamber and very likely do vitrectomy. A trauma hyphema with a high pressure is something that requires surgical drainage. Lastly, sometimes general anesthesia or laryngeal mask is not available. How safe is the use of sub-Tenon’s and facial block in repairing open globes? The facial block might be okay, but I think the sub-Tenon’s is quite risky. Two problems. If you don’t know where the rupture is, you could enter the globe in a soft eye. And the second thing is the anesthesia going to enter the vitreous cavity, which could be toxic to the retina. If the globe is soft, what would you use to fill the globe? I would use balanced salt solution, to pump it up, so to speak. I would not use Viscoat. I think one of the other questions earlier on was filling the eye with Viscoat, and the problem there is the pressure may well be uncontrollable. So you could use, in addition, air, or expanding C3F8. But I wouldn’t use Viscoat. Because of the attendant issues. And I would also not use silicone oil, because you’re not in control of the situation yet. Is it advisable to repair iris or lens washout at the time of initial globe repair? That is a judgment call you’ll have to make. I would say most of the time no. You close the eye and then understand what your repair has to be, because you may be able to put a secondary lens in, for example. It may take a day to find the correct lens. Repairing the iris is very hard to do in a soft eye. Or a just repaired eye. The risk of bleeding is quite high. If you touch the iris, even, it will bleed. So the point of waiting a day or two or three is to get control of the bleeding situation and enhance your visualization. The only thing I might add is: When I went through the questions, somebody asked about any special pediatric considerations. One of those is that the organism involved in pediatric endophthalmitis with ruptured globe in many cases is E coli faecalis, which is something that is very hard to treat with antibiotics. Vancomycin has been used, but there’s a high resistance rate. So the type of antibiotics used in your environment is important to know. Also management of the lens and management of potential amblyopia are critical.

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June 28, 2019

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