Lecture: Reconstructing the Traumatized Anterior Segment

A little bit about the management of trauma since it is something that every ophthalmologist has to deal with and trauma can be classified into two different groups, those trauma events which are open globes and those which are closed globes. The open globes can be classified into ruptures, penetrating trauma, intraocular foreign bodies or perforating trauma. Difference between penetrating and perforating is that, perforating goes inside the eye, penetrating is only partial thickness. So there are ways in which we can grade the trauma, certainly visual acuity is important in prognosis. Good visual acuity usually signals a good prognostic outcome. The other important indicator is the presence or absence of an afferent pupillary defect. And finally, the location of the. Injury, whether it’s isolated to cornea, whether it involves the sclera or whether it is posterior eye, makes a difference in the outcome.
Similarly, closed globe injuries can be classified, in the same way you have contusions, lamellar lacerations which do not perforate, superficial foreign bodies. Once again, the visual acuity is important, the presence or absence of an afferent pupillary defect and the location of the injury are all important prognostic factors.
So in a retrospective study of 150 patients with open globe injuries, the significant of all four of those classifications of those predictors were important but the most important were the grade and the pupil. So, it’s so very important when you first evaluate a patient with anterior segment or corneal trauma, you need to go back and look at these prognostic factors, the type, the grade, the pupil and particularly these to that level of vision at the beginning and the presence or absence of an afferent pupillary defect. With those two factors, you can get a very good determination of how well the patient is going to do.
So, one of the goals of management- first of all to prevent further injury. Very commonly patients come into the emergency room, they’re seen by non-ophthalmologist initially and sometimes the attempt to examine the patient can worsen the initial injury. So, our first goal then is to protect against further injury. The next goal of course is to restore optical visual function. Thirdly we want to restore normal anatomic relationships and then we want to prevent the longer-term complications including glaucoma and retina problems. So, the most important thing you can do when a patient comes in like this until you are in the operating room is to protect them in some way with glasses or a shield, some way in which there’s no pressure on the eye and no possibility of worsening the injury.

So the principles of management are, first of all to have a good surgical plan. You know when you go in to do cataract surgery or KPro or transplant, the steps are usually set for you. But in trauma you only know what you’re going to do really when you’re on the table, on the operating table but you need to go into the operating room with a plan in your mind, of course based on your assessment of the extent of the trauma. It’s important to make sure that you and your surgical team have the right instrumentation.
So, there are three things you need to be able to do. One is to conserve tissue, do not excise tissue unless it’s absolutely necessary. Secondly to minimize any further damage in the operation. And thirdly, always a willingness to change the plan. Finally, in addition to protecting the patient from further damage, you want to take steps to prevent infection. If you have a very small corneal perforation, often simply patching the patient will be adequate. Because there is stromal swelling that will seal the perforation. Cycloplegic may or may not be the right thing to do because sometimes the iris is what plugs and closes the wound. And if you go into the operating room you may want to leave that iris there until you are in a controlled situation in the operating room. Or do not use cycloplegia if the Iris is closing the wound. You don’t want to pull the iris away from the wound.

If patching is not a good option, another possibility is the use of a bandage contact lens. This is particularly helpful in patients with partial thickness lacerations and good tissue opposition. It’s good to use a tight contact lens which actually compresses the tissue. And we normally leave the lens in place for 24 to 48 hours unless the chamber is flat. And a bandage contact lens can also be used as an adjunct after sutures or a tissue adhesive is used.
Let’s talk a little bit about tissue adhesive. Remember that cyanoacrylate glue only sticks to surfaces from which the epithelium has been removed. So, you need to deepithelialize the cornea around the area onto which you are placing glue. This works unfortunately only on perforations under 2 millimeters, over 2 millimeters the glue would go inside the eye and cause a tremendous inflammatory reaction. So the glue is very inflamogenic. It is also extremely antibacterial so, it’s a good way of preventing infection in the wound.
There are two ways to put glue on the eye. One is what I call the drip technique in which one stabilizes the eye under a microscope, cleans with betadine and then uses a tuberculin syringe with a 30-gauge needle to extrude just a drop of glue and then you touch the area that’s perforated and the glue will immediately seal that area. The other way which is probably more commonly used and which can easily be done at the slit lamp is, to use a dermatological punch and use the punch to make a little 3 millimeter circle of plastic, put a drop of glue on that circle, attach it to the end of a wooden cotton tipped applicator with some ointment and then just touch it to the eye. The glue, the circle of drape, the wooden tipped cotton applicator and a little bit of ointment and just touch that to the eye, the little circle will be glued to the perforation.

Question: So they are asking like, do you leave that plastic right on the cornea.
Dr. Mannis: Yes you do, leave the plastic on the eye. You attach the plastic with ointments to the end of a stick, with the glue on the inside of the plastic, and just touch the eye with it and the plastic stays there and it’s good because it covers the glue so that the patient is very comfortable.

Qestion: And when should we take it out?

Dr. Mannis: You leave it until epithelium grows underneath it and extrudes it. You don’t have to take it out at all. You need to put a contact lens over it.

OK, there are some complications of using tissue adhesive. We mentioned one of them is if the adhesive gains access to the anterior chamber, you can have a tremendous inflammatory reaction including hypopyon. It’s very important to place a bandage contact lens while the glue is still wet before it dries. The lens actually becomes attached to the glue and stays on as long as the glue is attached to the cornea. So, glue is useful for wounds less than two millimeters in size.

When the wound is greater than two millimeters that’s going to require surgical management of some type. One should first culture the wound that becomes very important because all these injuries are presumably contaminated. It’s important to remove any foreign material from the wound. And to carefully inspect the shape of the wound because that’s going to determine your surgical technique. Sometimes inspection of the wound cannot be done effectively until you’re under the microscope. However, if you can, it’s important to inspect the wound early in the course of the disease. And it’s important to determine if there are portions of a laceration which are perpendicular and portions which are shelved. if you close the perpendicular portions first you will gain wound stability and this is because the shelved areas of the wound are generally self-sealing.

So there are a variety of needle types that one can use in repairing corneal wounds. There are round needles generally called B.V. because they’re used in blood vessels. There are needles with cutting edges and there are spatulated needles which are flat and generally, the spatulated needles are the best for corneal repair.

Here’s an example of a round needle, the tri curve needle and the type of wound they make and the spatulated needle. So, you can see the advantage of this spatulated needle.

OK, We showed you different types of knots that can be made. A surgeon’s knot which is the typical 3 1 1 configuration. And this is best used for wounds that are under tension, to separate because the first three throws lock the tissue together and give you stability. If you do not have a wound that’s under tension, a better option is a slipknot. And this is done not 3 1 1 but 1 1 1 in different directions. And this is the knot we used for most of the cases you’ve seen in the last two days. It produces a very small knot which it is very easy to rotate and allows you complete control over the tension of the wound.
This is not a reference to the book but there’s a wonderful book by Marion Macsai which is all about suturing in ophthalmology and it comes with a very nice CD. You can buy it if you go to the American Academy, so wonderful book which is very useful to have in your library.
One of the issues of geometry that many surgeons don’t understand is that, once you understand this you will have many fewer problems with your suturing. And that is the concept of a compression zone. This compression zone is the area between two sutures. If you have a larger suture you need a larger zone of compression or smaller suture will produce a smaller zone of compression.
And the best closure is when the two zones of compression overlap like this. So you would like that distance between two sutures to be slightly shorter than the length of the sutures. So if A, which is the length of the suture is larger than B, which is the distance between the two sutures, You’ll get a watertight closure. On the other hand, if the length of the suture is less than the distance between two sutures, you will get wound leak.

So, for example when we close a corneal wound as we do in keratoplasty, we don’t so much look at the length of the sutures as we do the relationship between the length of the suture and the distance to the next suture. And really, as soon as you understand this and employ this in your suturing, this goes for skin as well as cornea but it’s very important in cornea. Soon as you understand this you will have no problems with the wound leak anymore.

OK. Very often when we’re in the emergency room or in the operating room repairing a trauma, our goal is simply to get everything closed. But what I’d like to recommend is that you consider even at the first repair, taking steps to make the closure as meticulous as possible to promote good visual function. And if you take the time with the initial closure, then it’s possible that you will not have to go back and do reconstruction. So closure of the eye, first you want to avoid suture override, a wound override and I’ll show you what that means in a few minutes. Secondly you want to try not to remove any tissue at the primary repair, because you may need it later. Remember that we first want to close perpendicular wounds before shelved wounds, but as much as possible we want to place sutures in order to avoid astigmatism.

I’m going to show you in a few minutes how to close a Zig-Zag incision, also stellate incisions.

Let’s talk for a minute about wound override. This is again a little bit of geometry. In a vertical wound, you would like the distance between the suture and the wound to be identical on either side. That will produce very good suture apposition. If the suture is closer to the wound on one side and further away from the wound on the other side, then you look at tissue override.
Now on the other hand, if you have a shelved wound, it’s done exactly the opposite way. In a shelved wound, you do not want the suture to be equally distant from the front of the wound. if you do that you look at tissue override. What you want is for it to be closer on the optic side and further away on the acute side and that will produce good wound apposition. And you would like the suture to be as deep as possible without entering the anterior chamber. And as we said before we want to avoid tissue removal unless there is frank necrosis of the issue and it’s not viable.
And we’ve already said this but I think it’s worth repeating that, the perpendicular part of the wound, straight up and down part will open with normal intraocular pressure. A shelved wound will seal with normal intraocular pressure. So, in the operating room in the management of trauma, you want to close the perpendicular wound first. So, here you can see a graphic example of that. In the center of this graph, there is a perpendicular wound that will open with normal intraocular pressure. But the shelved part of the wound will stay closed. So, the tactic should be to close the center part of the wound first, that will maintain your chamber so you can close the remainder of wound in sequence.

Very commonly in the operating room when we’re faced with an eye with a terrible corneal scleral laceration and a traumatic cataract and uveal prolapse, we’re not thinking about astigmatism, you are thinking about saving the eye, but you should actually consider when doing your initial closure, placing sutures that will help you subsequently. And what you would like to do is to simulate the normal prolate shape of the cornea, which is steeper in the center and flatter in the periphery. So, you want to use longer sutures near the periphery and shorter sutures near the center, which will give you a more physiologic corneal shape. So, look that graphically and you will see that what the surgeon has done here is, to use longer sutures in the periphery and shorter sutures in the center and that will basically try to ensure that the normal shape of the cornea is preserved.
Here you can see an example of the operating room and you might say well, why would Dr. Mannis be worried about astigmatism in a case like this. This is a terrible laceration which goes from limbus to limbus. But you notice that we’ve placed longer sutures in the periphery and shorter sutures in the center, and what that does is reshape the cornea. In addition, anytime you place a suture you get some scarring around the suture.
So, in the optical axis, there’s going to be much less scarring here than there is out in the periphery. So, most corneal lacerations are not like this, most corneal lacerations are zig-zag, they are multi-directional.
So, how do we close those types of laceration? Each linear aspect of the wound should be treated as a separate laceration. So, let’s look for a moment at a Zig-Zag suture. The logical thing we would probably all do is try to close the ABC’s first. That’s actually not the correct way to do it. That’s because the ABC’s will often self-seal, if the linear portion of the wound is closed first.

So a logical way to do this would be, for example to take the central expanse and close it with four sutures. Then you take the second leg and do the same thing. In this case, they have used a running stitch but you can use a running stitch or interrupted stitches. The principle is the same that is, that you close the linear portion of the laceration first.
There are several other situations which require specific types of sutures. For example, this wedge incision and where we commonly see lacerations of this type and that can be done by using what’s called a mattress suture, where you put the suture in each side of the tissue and then pull the two tissues together tying the knot on the surface. The key to success is to make sure that the suture is at the same depth in both sides of the wound. Finally, there are stellate lacerations and these are extremely common, they occur from stab injuries most commonly. These are the hardest incisions to close and commonly the surgeon will try to close each apex one to the other but it’s usually very difficult and they almost always leak. So a better way to do this is to make, if there is room to make stab incisions between lacerations and do a running in and out suture that picks up each wedge of the star. This is a very challenging maneuver and requires a lot of patience to perform. Here’s an example we have got graphically what it looks like. This is actually not a stellate wound but a wound with two arms and you can see that the circuit really never closes the apex specifically, but each arm of the wound is closed, and that’s an effective closure. It unfortunately is right in the center of the pupil.
I’m sure that in this country, you see lots of motorcycle accidents. We certainly see a lot of them in the United States but we have nothing like what you have here. And very commonly in motorcycle accidents people hit the pavement and lose tissue from the surface of the cornea. If there is frank tissue loss, what one needs to do is remove any necrotic tissue and then consider, if it’s greater than two millimeters using a patch graft. If it’s less than five millimeters you can use a circular

technique with an imprint trephine and I’ll show you what that is in a minute.
One can use either a full thickness or a partial thickness graft. In a partial thickness graft where there is a reasonable amount of tissue on the posterior side, one can use a full thickness patch graft, sized to the size of the tissue defect, put it in position and then use overlay sutures to compress the tissue into the closure position. More commonly however, you have a larger area of tissue loss and those patients need to have sutured patch grafts. So, what you do is, you take a trephine slightly larger than the area of defect, make a partial thickness trephination and then use a blade, a 69 blade or something of that sort to excise that tissue down to but not into the anterior chamber. And then once you’ve made your lamellar dissection, you can take a full thickness corneal patch graft which compresses that wound and place it over the perforation. Here you can see an example of a full thickness graft over a central perforation around which you have taken away a lamella of cornea. And this technique produces a beautiful seal.
In the event of a laceration, what do you do with the iris? if Iris is extruded and the time between the trauma and the time you see the patient is short, it’s reasonable to treat the surface with antibiotics and then reposition the iris. If the iris has been out for 12, 24, 48 hours which is often the case, it’s probably necrotic or infected and needs to be excised. So, that patient will need to have an iris reconstruction at a later day. But what you don’t want to do is remove iris if you don’t have to.

In terms of post-operative care, almost all of these patients require topical antibiotics, you have to presume infection even if there’s not obvious infection. Secondly cycloplegia is important except except when you have a perforation with iris adhesion, that you want to leave that way until you do the repair because the iris may be helping you to keep the eye closed. In addition, all of these patients need to be monitored very closely for the development of glaucoma either from contusion injury to the filtration system or topical corticosteroid use, they are all prone to the development of high pressure. And you also want to watch out for endophthalmitis and it doesn’t have to occur within the first 24 hours, you can develop a late endophthalmitis, if the wound has been seeded with an organism that only gains access to the inside of the eye later in the course of the follow up.

In terms of suture removal, generally you want to remove sutures prior to vascularization of the wound. Most strictly in corneal incisions, the sutures can be taken out by three months and a good technique is to remove alternate sutures, remove every other suture to see if the wound is stable. So frequently if you have nine sutures, I’ll take out 1 3 5 7 9 and leave 2 4 6 8 to the next visit. That keeps the wound stable and you can come back and take the remaining sutures out.

So I think the messages I would like to leave you with are:

Even in an eye which is badly damaged unless there is complete extrusion of the intraocular contents, you should approach the surgical management as if the eye could be rehabilitated. In addition, different suture techniques are obviously needed for different types of lacerations, so you need to try and figure out the geometry of the laceration before simply putting sutures. The surgeon’s knot, the standard 3 1 1 knot is good for achieving stability. But the slip knot will give you the best control for the remainder of the wound. And so, what you’d like to do is, in your additional closure, use the suturing technique which will make then wound astigmatically neutral. So, I hope that these techniques will help you a little bit in managing trauma.