This Live Lecture encompasses orbital foreign bodies. Case examples and photographs are examined.

Lecturer: Dr. James Fleming

Transcript

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DR FLEMING: So… Let me open this up. And this is Dr. James Fleming. And I am the speaker today. And from this, I would like to start with my topic today — is orbital foreign bodies. I’m Dr. James Fleming. I’m the director of the Hamilton Eye Institute at the University of Tennessee, and as a professor and teacher, I always like to start with a case presentation, to really let the audience think about what the thing we’re covering today is. And there are a couple of questions in this. So let’s get into this discussion of orbital foreign bodies. Case number one is a 55-year-old male, he was struck below the left eye with a single pellet from his partner’s gun while he was duck hunting, I distance of 10 yards. Immediately his vision went to no light perception, globe was intact, 5 millimeter unreactive pupil, and on initial examination, he had a 30 diopter left exotropia. This is the CT scan, demonstrating the pellet that entered his right globe, from the inferior portion — right orbit, excuse me — missed the globe itself. And you can see these opaque materials in a very interesting spot. If you take the CT scan and put it three-dimensionally, as you’ll see on the left side of your slide, there’s a pellet in the back. We took the liberty of coloring the pellet. This is the superior orbital fissure, and the pellet right in the optic foramen. So the question posed: with no light perception, 30 diopter XT, to care for this patient, you would recommend: A, exploration and removal of the foreign body, B, observation, C steroid therapy, and D, MRI scan to assess the optic nerve. I’m inviting the audience to participate and answer the poll. And everybody gets to do this. I guess I do too, because it’s in front of me also. Submit your answer. And we’ll look at this. And I will proceed on. And we’re gonna look at this question a little bit later also. As you can see — the host is sharing poll results with us, and we have a pretty wide spread of treatment options that have been looked at. So I’ll close this and move on to our next case. Case number two is a nine-year-old male who fell on a broken wooden handle two months prior. Wood was removed and the wound healed over two weeks. He had new onset swelling and pain over five days. This is a photograph. This is the original wood piece removed. Five days later, you’ll see the stitches in place, the eye was swollen, it had gone down previously, so we have a new onset swelling and a wood handle that has been removed. So a quick case… Two questions. The initial MRI did not show retained foreign body. Your next action is… With this five days out, new swelling… A, repeat the MRI, a repeat MRI is needed to find the retained foreign body. B, antibiotic treatment should clear this. Or C, exploration immediately is indicated. So everybody gets to vote. And choose your first action. You may want to explore. You may whatever — all of these may be applicable. But I’m asking what next. The first thing to do. And we’ll see what kind of results we get in this group. This is one of the things. Again, I’ve spread out the answers. So this is a good group to talk to. Because the opinions are spread out through both of these questions. I come from the Hamilton Eye Institute at the University of Tennessee. Here we go on foreign bodies. I’m gonna take you a tour on foreign bodies after the two cases. I have no financial disclosures. I have in the past and I’ve given all the money to charity. Orbital foreign bodies — it’s primary penetrating injuries. There’s a subset, orbital anatomic considerations. We’ll go through that. And the special thing we as ophthalmologists need to understand is imaging and what we can do with that. The fourth thing to consider is: foreign body characteristics. And we’ll get extensively into that. And the last is how to go after these things. If you’re an ophthalmologist, and you deal with trauma, you understand the physics of trauma injuries, and the physics have to do with mass and velocity. If you notice this equation — E=1/2mv². The mass makes a big difference, because it is squared. The ability of a missile to penetrate into the orbital tissues depends on velocity and mass. You have a few things that occur. You have a permanent cavity by the path of the projectile, then a temporary cavity by the shock wave that has impacted into this. An example of what a high velocity bullet or projectile will do — not only does it give this permanent cavity with — in this case, a deer rifle or large animal rifle. The injury path is this wide. And if you don’t think it really occurs this way, all you have to do is look at the cavitation that has occurred in the CT scan. Even though it was a single path here, the injury goes from very medial to very lateral. The destruction is quite significant. Optic nerve has been not injured directly, but it’s injured indirectly from all the shock waves. The second is low velocity injuries. This happens to be a pellet gun. This pellet gun put a lead pellet within this orbit. No significant shock wave, no significant external trauma outside the pellet itself. So the question that then comes is: what do you do with the pellet? Because there’s not that much significant associated injury. There is an interesting thing that has occurred in war, and it also occurs in civilian life. And that is: the number of ocular injuries has continued to increase. And we will see more and more of these, because of our active society. In the US civil war, the number of injuries that occurred that took a soldier off the battlefield was 25%. As you can see in this group, Desert Storm had 13%. This had to do with body armor and protection. The same thing happens in sports when people wear headgear and all the things that occur with this. It’s protection, but it’s often not good enough for small injuries. This is a classic example of what has changed over time. And what we have had to do. This pair of glasses used to be issued — as you can see, injuries can get around the side of it. It used to be called birth control glasses because none of the young people would wear them. They weren’t in style. I think they’re back in style now. A company called Wiley-X showed me this. This is an IED piece, 3 millimeter thick polycarbonate. This injury would have been substantial if not for the protection associated with this. But the point I’m making is high velocity and medium velocity injuries are increasing, not decreasing. Wear your protection. So the next section I want to get into is orbital anatomic considerations. If you think about an orbit, it really is a compartment like many other compartments in the body. It has a set of muscles, nerves, blood vessels. It’s fairly contained, a number of things penetrate into the compartment, but because of its periosteal lining, it does do certain things. Also, because of its bony structure, it does certain things. Extraocular movement depends on the muscles and the function of what’s called the orbital septal system. And I’ll show you a demonstration of that. The optic nerve itself has unique characteristics. And the other, in the full face, the orbital volume maintains globe position. So if one orbit is out of place compared to the other in some type of injury, the globe position is affected. So here’s our compartment. Everyone talks about the orbit as being a pyramid. It does have a wide base in the front, goes to the back. The optic canal we were looking at a moment ago in the first case. But it widens past the aperture, and many areas penetrate through this. And you can see it’s not exactly a pyramid. It’s got round contours from anterior to posterior. The floor goes up 20% anteromedially, but it’s literally a cone, and that impacts orbital foreign bodies, because they’re directed to the posterior aspect, as we saw in the first case. The second piece I would like to discuss is what’s called the orbital septal system. Leo Koornneef described this, and he took thick sections of the orbit to isolate out a septal system that he saw. This is a series of photographs from his original article — drawings from his original article — in which the recti muscles are within the orbit system in their position. And if you notice, there’s a septal system that goes out to the periosteum, and suspends these orbital pieces throughout the entire orbit. Jonathan Dutton was good enough to get his artist to really kind of draw this in a three-dimensional-type drawing, instead of this cross sectional drawing. Which shows that there’s a septal system. This system must be maintained to maintain balance of the extraocular muscles. It also acts to baffle and change things, as far as injuries that enter the orbit. It is often why extraocular muscles are greatly affected, even though the muscle is not directly affected. The septal system is injured. Like an orange on the side, this septal system just has different compartments that you can see, and like an orange, each one is somewhat separate from each other, even though they’re part of the whole. The full orange or the whole orbit is the big compartment that we deal with. The optic nerve is special, and we all know this quite well, in the fact that it has dura associated with this. Here’s the nerve, suspended with its arachnoid and pia. CSF goes through this system. This becomes a second compartment within the orbit, in which injury can occur. And in this case, the injury occurred through the optic nerve, and as you can see, hemorrhage came from posterior to anterior in this particular individual. So again, a unique compartment in the body. It requires special attention. And when you see things in the retina, dilated fundus, you get information as to what’s going on. So now let’s move on to the types of foreign bodies, and the major definition of foreign bodies — the major division of foreign bodies comes into inorganic versus organic. And so the list of inorganic foreign bodies is primarily metal, glass, plastic, fiberglass. And what happens is… Because of all these projectiles that come through, we’re always trying to determine — has this projectile entered the orbit? Is it really there? And where is it? This slide delineates size, location, and composition. This is a radiology breakdown of what we should see with each one of these. Metals you’ll know — because their increased density can be found with very small, minimal sized pieces of metal that can be tracked within the orbit. And we’ve all seen this. Glass is much different. The variation in the size, as you can see, from 0.75 and 2 — minimum size that you need. It’s easier when they get larger. It depends on lead content. It’s really heavy metal content. Anything — glass made with a base metal in it, lead is the most common, but there are others. Cobalt, et cetera. So you’re looking for the metal that shows up with the glass. Plastic and fiberglass are radiologically inert. The answer is… Looks like air. They’re not there on the scan. There’s no moisture within them. There’s no configuration. So what I call it — linear air. Or it looks like air. So this is the basic tenet in inorganic foreign bodies as to what you’re looking for. Classic easy example is a shotgun blast from a hunter that got hit in the face. And what he has… Is multiple foreign bodies, throughout. Which you can see. And they’re easy to see on plain film. They’re all over the place. You can localize them by a number of different techniques. But you know exactly where they are. Metallic foreign bodies. This is a little bit different. This is glass. And so the question is — as my residents ask — where is the glass? And the answer is it often looks like the bone associated with it. It has a different configuration. Look at this. And depending on the density of the metal, it will tell you where it is. Subcuboidal glass like windshield glass is very difficult to see. This is glass. I’ll give you the example that you need to see. And that is… This glass has been taken out of this individual, and this has some lead within it, yellow glass, and it’s fairly easy to fix. You have to go in and pick it out, but you can x-ray or CT scan to see if you’ve got most of the glass. Do you need to pull all of it out? That’s a question we’ll get into in a minute. Here’s an individual who walked into a shooting range in which a crossbow unfortunately was discharged when he wasn’t cognizant of what was going on. And this crossbow injury caused a significant injury here. In my slide, you can see the point on the crossbow. But what else you see is this linear air-looking thing on the x-ray. And what that is — is basically fiberglass. Fiberglass, inert. Doesn’t look like anything but air on a CT scan. So what you see is this individual that has received a deadly injury, through his orbit into his brain, with the fiberglass shaft in there, in the tip, all the way in the base of his brain. An unfortunate accident, but you get the idea what the material does and how it looks as a foreign body injury. Another easy one to pick up and look at has to do with the base metals associated with this. And this is a metal piece that was in an individual that felt that they needed to saw something, and used the wrong blade. You can delineate the extent of the injury and whether it traverses other compartments, other than the orbit. And this one indeed does. It goes into the anterior cranial fossa. And this unfortunate individual received an injury from a polishing blade that came apart, and basically at high speed, by the drill, went into the side of his face. He is doing well. It was extracted. It took a multiple team to bring him back together. But this type of injury gives you an idea what you see on imaging. Let’s move on to the other group that you need to talk about and that’s organic foreign bodies. Organic foreign bodies really should be divided into two types. And it has to do with how much moisture they have in them. The moisture associated with a pencil lead or a pencil is very dry wood. It has a very specific characteristic. Wet wood such as this bamboo shows up entirely differently. So let’s explore this problem of wet wood, dry wood. Because that’s the first question as an ophthalmologist you have to ask. Okay. It’s a wood foreign body. What type of wood is it? What is related to it? So CT scan evaluation of someone with dry wood. Comes out as a cylindrical lucency. It has no fluid within it. It basically looks like air. The problem is it doesn’t separate pieces well and you can get splinters that show up as one piece on a scan. Hydrated wood is even worse. It’s isodense to fat. Really difficult to find. Almost impossible to find. So when you know you have hydrated foreign body, you know you have a real problem in isolating this lesion. That goes back to the second case. This was a 15-year-old that was ejected from a vehicle and hit a tree. The tree happened to be a dead tree, with dry wood, and they came in and showed me the scan, and for those looking at the scan, you can see the orbital fractures. If I can get my… There it is. In here — you see the multiple orbital fractures. The lateral wall, the anterior orbital rim, floor, medial wall. But what we have here is linear air. We pulled six dry wood fragments out of his maxillary sinus. Linear air. Knew what the foreign body was. You know what you’re looking at and what you’ve seen. Air in the maxillary sinus does not look like that at all. So let’s go a little deeper into the problem of organic foreign bodies and identifying it. Most of these are what we call impalement injuries. This is indeed one. He fell on a stick, after running away from the police. When he did, this impaled him. And it’s here. You see linear air. Nice part is it sticks out the other side, so you know you’ve got a piece of wood. The thing is — if you look a little closer, you’ll see more than that. What you have down this medial wall is more than linear air. Is this a foreign body or is this not? First service pulled this out. I won’t do this one first. It has to do with… There it is. Again, this is the foreign body. It looks like air. This is wood. This is dry wood. So the first service did this. So they pulled it out. And that’s his scan. I’m gonna get back to the scan. They thought they did a great job. They told me it was all over. I looked at the scan the next day and I said it’s not all over. The reason I’m saying that is if you look back along this wall right here, here’s the linear air. So we had to go back in, explore this orbit, and get the other piece of foreign body out. This is a significant problem. So you’re looking for retained foreign bodies that had fractured. Well, this case got much more complicated, because in a couple days, he was more symptomatic. And so I went back and looked at the original scan. Here it is, low in the maxillary sinus. And if you see something — look at this item right here. This is in the infratemporal fossa. Being in the infratemporal fossa, after being impaled through the orbit — this is an unusual place for air to stay. I asked them to scan him again in four days. What happens is the air changed. Look at the air in the maxillary sinus. Look at the air in there. It’s all shifted around. The bubbles are different, the blood is different, but this thing is the same. Ten days, identical. Air doesn’t — it should absorb. It should go away. This did not go away. I then did what’s called a lung window. And I’ll get into that in a minute. And looked and said — okay. Where is the foreign body on the original one? That looks different from air. Standard foreign body doesn’t do this. But if you look at the other, you can see that. If you look at the original, there’s the retained foreign body we had to go after after they took the original stake out. There’s the pieces that were there. But lo and behold, I took the lung window and looked at this piece. It’s not air anymore. It’s different. But this is the piece we pulled out of his inferotemporal fossa. Excuse me. It had been the main fragment that we pulled out of the lateral wall of his orbit, plus the big stick that was associated with that. But there they are, put back together. And here’s why. CT scans are on what’s known as the Hounsfield scale. It was developed in Britain a number of years ago. The scale goes from 1 to 4,000. And it has 1 to 4,000 shades of grey. Water is zero. Air is -1,000. Bone is around 395, 4,000. That sounds good. You should be able to pick it up. There’s a problem. Every x-ray scanner only shows 256 shades of grade. Therefore you’re taking 4,000 to 5,000 shades of grey and picking 256 to look at. So you have to choose it in the window of what to do with. So what the presets did is they set bone from 500 to 4,000. Therefore you can pick up all the things associated with this. If you narrow that window down, and take the highest window at 2,000 instead of 4,000, what you get is a 500 to 2,000, and all of a sudden anything that is not truly air starts looking grey. And so I’m gonna back up a couple. Grey. You see my grey piece? That’s the lung window. You can do it by changing the numbers. But my recommendation is go to the presets. Put a lung window on. Look for organic foreign bodies, compared to linear air. So that’s my pearl for today, of trying to find the 256 shades of grey that is buried in the 4,000 Hounsfield units that you need to know about. Now, let’s talk about green wood. This is the great dilemma. Another impalement injury. A stake came through here. You know it’s a significant injury. The lateral sphenoid wing has been disrupted. The bone has been pushed aside. He said I pulled out the stake and it came out. There’s no more foreign body. Now what you have is wet wood, green wood. Is there foreign body retained in there or not? The answer is… I can’t tell. And if you look at it by CT scan, MRI, again, you just can’t tell. The injury is there. The material is all there. But you have no idea what’s going on. What happens is a couple of days later — and this is the key to this — three days later, guess what happens? The body tries to reject the foreign body. It creates an inflammatory response. And you get an encircling inflammatory response around the foreign body. The next thing you know, what you have is a foreign body that is glowing or ring sign, and as this coronal shows, it’s a ring around the foreign body. You can identify the foreign body by the inflammation. So the key to this is… Green wood will show up through inflammation. It may not show up at the first scan. But you need to repeat the scan three to four to five days later. If you suspect one, you don’t just let these people go. You rescan them or you watch them. So back to the other ones, retained foreign bodies, dry wood with MRI — we did CT scan. This is MRI. Dry wood — hypointense to fat on T1 and T2. It’s a dark cylinder, circle. Shows up very nicely. This is wood. This was a hunter that fell. Impaled himself. Took the thing out, went to the emergency room, they sewed up the small laceration and left this piece in there. So that is what he has. MRI with retained organic foreign bodies. MRI shows green hydrated wood. It’s isointense, but it begins to glow with gadolinium after inflammation sets in. So what you’re looking for, if you can’t pick it up on the first time, don’t give up. Rescan them in a few days. It’ll begin to show what’s there. So the reality of imaging, because of this technology of the size of the image, and the type of foreign body, 40% to 50% of all organic foreign bodies in the orbit remain unidentified before surgery. We reported 24 of these in 1999. Another group, as I noted below, reported about 40 of them in 2010. Found essentially the identical problem that we said. It has not changed. So let’s go a little bit into the characteristics of foreign bodies. Inorganic. And the thing I alluded to is inorganic foreign bodies, glass, plastic, metallic, are usually inert, and they’re well tolerated. We reported that in 2004, and we have another group that’s coming out in the next year. So 55 retained metallic foreign bodies, up to 40 years in place, no real problem. So our recommendation stands today, as it did in 2004. The interventional management of this type of foreign body depends on the resting location, of the projectile, causing pain, inflammation, or other functional problem associated with it. Metallic foreign bodies that are not inert are a small group. Pure copper, as we know, gives significant problems with retina problems. Also in the orbit, it’s very reactive. It’s a metal that requires removal, just because of its activity associated with it. Similarly, iron, old iron rusts. It causes surrounding inflammation. If it’s a small piece, it will be eaten up very quickly. If it’s a large piece, it’s gonna need to be removed. Lead will degrade. You can get lead poisoning. However, the lead must be without antimony. This is a stabilizer, used in most bullets. In most hard lead. Not the solder lead. If it’s been treated with antimony, it’s stable and can be around forever. It doesn’t cause problems. Lead poisoning only comes from pure lead that has not been treated. Classic question many people ask — these are the children playing, and BB guns or air guns — what do you do about a BB injury? And it turns out… BBs, you’ll have to check the composition, but the one here, called a Copperhead, it’s not truly copper. It’s steel core with zinc plating, acrylic lacquer or coating. They’re very well tolerated. So there’s really no need to go after a BB, unless it’s impinging on the eye itself, the globe, or affecting extraocular muscle function. We have a whole group of BBs that we just follow without any intervention. So let’s go back to our case one. Case one. The 55-year-old male, struck below the eye. Had the pellet. You saw the pellet. And here we go. Here it is. The pellet is in there. There it is, right back in the optic nerve. He has no light perception. It happens right at the time. So I’m gonna ask the same question again. One question. To care for this patient, would you recommend: A, exploration and removal of foreign body, B, observation, C, steroid therapy, or D, MRI scan to access the optic nerve? So let’s put the question back up and ask it again. I would like to wait just a second. And we’re gonna get to questions after this. And I’m delighted to answer questions for the entire group, as you send them in at the end of the lecture. They’ve given me a tight timeline, so I’m trying to move ahead. So let’s see what we get. What we’ll do is go down to the question and why we thought about each of the answers. So exploration and removal of foreign body… 22% felt it was still indicated. Everybody got away from the steroids, which is interesting. MRI is 33%. And I’m gonna go with each one of these. I’ll take exploration and removal of foreign body. If somebody is instantly no light perception, it’s into the optic nerve, can you regain vision by decompressing an optic nerve? And I’m afraid the literature does not hold true on this. Cannot fault anybody for thinking about it, knowing it, I cannot… But if you give me what I call evidence-based medicine, there’s not a great indication to do this. It’s in the optic canal. It’s right at the base. The injury has been done. It’s over. Observation is what we elected to do. Because we didn’t feel we could benefit the fellow from other materials. The other interesting thing is — steroid therapy — there have been two major studies. One on traumatic optic neuropathy, which didn’t really show any difference in the treatment of injuries, and then there was the English creche study for intracranial injuries of 10,000 people, and they showed some downside to using it in people with other significant injuries. So I caution people for steroid therapy. Can I fault somebody for using it? No, I really can’t. But the injury is still out. And then the last one is the most interesting. MRI scan to access the optic nerve. This person in the United States was duck hunting. If you know the rules of duck hunting in the United States, this is a steel pellet, not a lead pellet. It’s magnetic. This fragment will move by MRI scan. So it is probably contraindicated, if you know the material you’re dealing with, this is steel — you are gonna shift this. And the real question came to us is — say he has other injuries, and needs other MRIs in the future. Would it be of benefit to go back to A and explore and remove the foreign body because he needs MRIs? We have entertained that. We have not done it. He knows he has a steel piece within his orbital apex, and if he had an MRI, there’s a significant risk that this may shift. So let’s go to our next group. The nine-year-old male. Fell on a broken broom handle. Two months prior. Wood removed. Pain and sudden onset of swelling over five days. Let’s do the question again. Your next action is: A, repeat MRI is needed to find the retained foreign body. Antibiotic treatment should clear this. Or C, exploration immediately is indicated. This is my question. What should you do first? And so I’ll see what the group says. And I’ll wait on this one. Because I’m interested to see what kind of discussion — the discussion has shifted in the group. That was dry wood. Because it was a broomstick. But it didn’t show up. And we should see this. I guess everybody knows that the antibiotic is not gonna clear this. Agreed. The group’s got it. 75% said a repeat MRI is needed. And the reason is the inflammation will set in around the foreign body. It will outline the foreign body. It will give you a ring. Exploration was immediately indicated after the MRI was done. I agree with those two answers. And to go back in, once you’ve identified where the foreign body is. Here it is. That’s the original wood piece. Here’s the four more pieces of the splinters found in his orbit. He is now, without swelling — the foreign bodies have been removed. He’s doing much better. This has illustrated the big problem with these. Wood pieces will splinter. Organic foreign bodies are a significant problem. So organic foreign bodies — usually it’s trivial trauma, breaks off, small wound site, they suture it, most of these are long, thin structures. Twigs, pencils, things that classically will move. It strikes an orbital wall — remember, we talked about that. And it penetrates the thin walls, directed toward the apex. And look out for fragments. Organic foreign bodies… Delayed inflammation. Repeat imaging. Understand the characteristics and the foreign body type. So let’s get onto the extraction. What happens with this group of people is that, as you try to get to the foreign body, it moves deeper within the orbit. So my answer is: trap it if possible. If you can get a ribbon, retractor, something, around to the back of the foreign body, and then dissect to it, you’ve got a much better chance of getting all of it. I will follow the track, but I will try to trap it. The easy thing to do is to try to find something that you can get behind the conjunctival surface or something, to hold it, and I’ll follow the tract along a tear duct probe. Expect multiple fragments and look for them. Don’t tear up the orbit or tear it apart. The other thing is to back out if you think you’ve done a good job, and wait for the inflammation and repeat the MRI or repeat the scan to see if you can identify this. What’s coming down the pike… Stereotactic localization is out there. It involves preoperative MRI or CT scan. It’s a system of intraocular localization of surgical instruments superimposed on a screen so you can isolate it. The only problem is it accurately locates the bony landmarks only. So soft tissue intraoperative changes cannot be tracked. So if you move the foreign body, it’s shifted, it will get to an area, but it will not guarantee that the foreign body will not move on you. And that’s the downside of using this. What can you do inside the operative suite to help you localize it again? There is C arm localization that can be used for metallic foreign bodies. This is a metallic foreign body here. C arms are used by the orthopedic people. You can pull it into the operating suite, and localize it. Especially something that shows up fairly easily with this. And it gives limited soft tissue differentiation, but you can really isolate where — especially if you put a localizing instrument next to it, you know where you are, in two or three dimensions. Evolving technology is intraoperative scanning. Both of these, whether this is the MRI suite which is in our children’s hospital, this is the MRI suite where you can literally put a surgical procedure together, get down, see if you’ve still got something, put some instruments in that are non-magnetic, and then rescan them in the operating room to look. I have not used that. But it’s there. The other is the MRI here is — the CT scanner here — is a small transportable CT scanner, and it can be used intraoperatively. So… Question number three… Since we’ve revisited the two questions. One is: characteristics of penetrating injuries that are increasing in frequency and type. The orbit is a unique anatomic structure that affects the management of foreign bodies. Composition of the foreign body requires individualized treatment. Or the last answer is all of the above. So I’ll let everybody answer the question. And we’ll see what type of answer we get. It’s been very good to see shifts in the other one with the discussion there of what to do. That was too easy. Everybody got it. Let me get my screen moving again. Orbital injury requires knowledge of foreign body characteristics, knowledge of foreign body timeline. Knowledge of characteristics of the viewing window of the image display. Or all of the above. And we’ll see what we get here. Again, 93%. The group has changed their view on these, and I hope I’ve been able to let everybody think a little bit differently about it. I just went through those two things. The intervention is really evolving significantly. And as we get complex foreign bodies, as the scanners will allow us to do this intraoperatively, we may do a much better job with some of the deep foreign bodies that are associated with this. So I would like to thank everybody for listening to me. Now I think we’ll go to a question session. And so please post your questions into the group, and we’ll begin to answer them. And… This is an interesting scenario for me. Without being able to talk back and forth, I like to hear what the group has to say. But we’ll see if we have any questions. If we don’t, well, I’ve enjoyed the conversation with everybody. Sort of a conversation back and forth. I think we’ve changed some people’s thoughts about orbital foreign bodies a little bit.

>> So, Dr. Fleming, if you want to stay on for a few more minutes, if you want to stop sharing your screen, it looks like we got our first question in.

DR FLEMING: Very good. I’ll stop sharing my screen. Do I need to click on chat?

>> You can click on Q and A.

DR FLEMING: Very good. Somebody asked that I go over the temporal cavity picture. And somebody asked the second question… Was the use of magnet in foreign body removal. I’ll take the magnet first, because it’s the easiest one. If you can get the magnet between the foreign body and you without the globe or some other structure in between, absolutely use it. You can use it to pull it out. It was used many years ago in intraocular foreign bodies to pull it to the surface. But that’s that. I’m gonna go back to the pictures, when I have to pull it back up in a minute. I’m scared if I do that right away, I’ll lose my connection here. A bit off-topic — I’ll read this next question. I would like to know how would the green and dry wood intraocular foreign body appear on B scan. It does pretty well on B scan. It has to do with the internal reflectivity on B scan. Both CT and MRI work with water. And B scan does not. So it’s gonna give you a little bit different characteristics. So go back to the B scan characteristics. It’s got an interface on the system. I would guess that the interface between the green and the fat, because it’s isointense would give you difficulty. It might be a little helpful. It hasn’t been great for me in the past. I’ve done better with CT and MRI. My question with regard to organic foreign body. Do you insert a drain at the conclusion of surgery, to lessen the inflammatory edema for the next coming days, postoperatively? I usually do, because it’s gone across there. I usually leave the drain one day, maybe two. Not that long. Again, the inflammation is usually associated with materials. And if you wash out the tract a little bit and get the fragments out, that’ll usually do pretty well. How do you check the intraocular foreign body with penetrating trauma? That goes down to you’re looking for something that has gone into the globe. Which goes into a different set of questions for us. You can pick it up on MRI and CT, but also you need B scan. And to do a dilated fundus exam for that. As a routine, would you use antibiotics routinely, pre and postoperatively, and would you tailor them to the kind of foreign body, using antifungals or foreign bodies such as wood or plant material? The answer is for antibiotics and organic foreign bodies, yes. I would do it. I haven’t used antifungals as an original. You can culture the material. And see if you get anything. All of these are dirty. The organic foreign bodies. Because they have multiple pieces of bacteria. Cloth. All types of things are brought in with this. Usually they’re slow. Low velocity injuries. So they bring materials in with them. The inert ones, if they come in at high speed, they’re usually sterile. Bullets, et cetera, are not that much, unless they go through a shirt or other material and drag parts into it. If you see a foreign body that has a dirty tract, we wash it pretty profusely to try to get the fragments of wood or whatever is in there out of there. What are the non-surgical options for managing non-inert foreign bodies? Observation is the one we use. Non-inert foreign bodies. I was thinking inert foreign bodies. Non-inert foreign bodies… If you have… This person can’t go to surgery and you can’t kind of open the wound or bring it out or whatever. There’s a group of these that will be — the purulent infection will force it back out. You’ve seen this in other parts of the body. The hand, the foot, the leg. They step on a piece of splinter, it’s there for a week or two, literally pusses out and is spit out. The problem is that the orbital septal system gets chewed out by the infection. So there are not good options in the eye. Do you put antibiotic in powder form in the foreign body tract postoperatively? I have not. I would be interested if anybody had evidence-based medicine that shows that. We as ophthalmologists put topical antibiotics in and around the eye all of the time. I would not put ointment in, because it can get foreign body reaction. And you can get some tissue penetration from that. But I just don’t know good studies associated with it. Can you leave some types of intraocular foreign bodies? If it’s inert, interocular is a different material. Yes, you can. I reported a case with Dr. Hamilton. I’m from the Hamilton Eye Institute with someone who had a piece of rock for 52 years, until it worked its way out and was floating around the eye and he wanted it removed. Here’s an interesting one. What’s the optimum time of surgery? With an organic foreign body, I’m not inclined to wait a long period of time. Two or three days. Are there any x-ray equivalents to lung windows? You pose a good question, and I really don’t have an answer for that. Unless you just turn the amount of penetration down and try it. I have not read anything where it’s been used. The next one, a patient with a metallic intraocular foreign body. Is it near the inferior lateral wall of the orbit after penetrating globe? How do I manage it? I don’t worry about the foreign body in the orbit. It’s more the penetrating foreign body in the globe. Deal with the globe and let the metallic foreign body sit. When you leave a foreign body and don’t remove it — same answer. If it’s one of the inert materials and it came in, I’m not gonna go after it. Inorganic foreign bodies, inert stuff, we watch them. We may cover them with some antibiotics if we think it’s a little bit dirty and we just watch. Is there a place for steroids in the management of patients with intraorbital foreign bodies to adjunctive surgical intervention? Maybe in acute inflammation after it’s been treated with antibiotics and you’re trying to calm down the orbit. If you’re a believer in that, I would do that. Okay? I’m gonna attempt the last one. The temporal cavity. And let’s see if I can get back to my PowerPoint presentation and do that, and get into shared screen again. I’ll show you the temporal one. I’m gonna shrink this. I’m gonna close this question session. This is the infratemporal fossa. This is this lung window. And you see it’s grey right here, where the air is black. Grey where it’s black. Those are the two. And if you look at it — back to the standard bone window — we were looking at a bone window. You see air and you think it’s air, but it’s not. It’s the other. So there it is, there it is, and this is over a ten-day period. Air should absorb, and it did not. You look at the window. There’s black air. And that’s the lung window. And you see it as grey. If you look at this one, again, grey, it’s not air. And this one absolutely is not air. So we have to go into the infratemporal fossa to get to it. Q and A? Do I have any more? The temporal cavity? At a subdivisional level, what test would help us detect retained foreign body, apart from evidence of swelling? The problem is… What you have to do is wait for the swelling. You can re-MRI them in 3, 5, 7 days. You’ll still get the inflammation. Even if it’s not exteriorized. You’ll get inflammation. If it’s not there… We had one foreign that was in five years and finally got secondarily infected. I don’t know why it went five years. We were able to find it. And then one of them is… Sorry about my cough. What are the applications for the orbital septal system? I put it in there really to discuss the injury that occurs by a foreign body going through the orbital septal system. And has to do with… The second piece is, if you’re a surgeon going after the foreign body, you have to be cognizant that there is a septal system and you’re trying to not just go in and take a scissor and spread or break the septal system while you’re trying to find this foreign body. You’re trying to do minimally invasive surgery associated with it. Back to the lung window… Thinking about this question… When you do an x-ray, you either penetrate it very dark or very light. I would be interested in… This has not been done. Is to take a standard skull film, and shoot it at different densities, and see if it can make a difference. That’s an interesting question, but I can’t give you a straight answer. Okay. I think I’ve answered all the questions. I have no open questions. I would like to thank everybody for joining me, and have a wonderful afternoon or evening, or whatever time in the world it is. Oh, I have one more. I have a case of lost vision after trauma to an optic nerve canal. Can I do a test to determine if there is a catting in the optic nerve, VEP, et cetera. This is a timeline question. What you have to do is wait and see. I tell people I don’t give up on optic nerve injuries. I give them time. Let edema go down. If you use steroids, fine. But there’s not great data, as I alluded to earlier. Just give it time and see what you can come up with. Thank you very much.

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February 24, 2017

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