This 59-year old patient had a history of long standing exotropia with limited horizontal movements of the eye. It’s unclear if she had it from birth but probably had it from her early childhood. Dr. Wagner maximally recessed the lateral rectus muscle and resected the medial rectus muscle. He performed the surgery in both eyes but only one eye surgery is demonstrated here.
Surgery Location: on-board the Orbis Flying Eye Hospital in Bridgetown, Barbados
Surgeon: Rudolph Wagner, MD, Rutgers – New Jersey Medical School, Newark, NJ, USA
Dr. Wagner: This is a 59 year old patient with a history of longstanding large exotropia. It’s unclear whether this was present from birth, but it certainly started in young childhood. What’s unusual about the case is that this large exotropia present is associated with very limited horizontal movements of the eyes. Her vertical movements are preserved, but the horizontal movements are not. So we plan to reassess the lateral rectus muscles at the same time, resect the medial. I’ve grasped the eye at the limbus and I can move the eye laterally. When I attempt to move the eye medially, I am barely getting to the midline or perhaps slightly beyond the midline. That tells me that the lateral rectus muscle is restricted. Perhaps there was a paralysis of the medial which caused this at a young age. We’re not sure. Visual acuity is very good in both eyes. So this is interesting because she has had this for a long time.
She probably has alternate suppression, which is avoiding the symptom of diplopia. She prefers the right eye for fixation. In fact, when she looks straight ahead, she has to turn her head to the left because she can’t keep either eye in the primary position. The question is, are you concerned about the diplopia postop? We are a little bit, we’ve explained to her that if the history is true and she had this at such a young age, she probably developed some suppression. A change in her alignment may give her a temporary diplopia as her sensory adaptations adjust to the new position of the eyes. So the first thing we’re going to do is make a conjunctival incision. You know, there are many incisions that you can do for strabismus surgery. In this case, we’ll do a standard limbal incision because I need the most exposure possible to be able to visualize the entire surgical field.
We did instill two and a half percent phenylephrine in the eye prior to surgery to promote hemostasis. At least at this point it’s helping and when you make a tunnel, you want to avoid the inferior and lateral rectus muscles. I’ll make another tunnel superiorly to avoid the superior rectus muscle. So now should be able to hook the lateral. I’m going to take a large hook first and I’m going to attempt to hook lateral rectus muscle here and I expect it to be tight and it is. Using a Stevens hook to try to get behind the muscle, then I can replace this with a large hook.
You can try to come out the other side where the incision was made previously, but this is a very, very tight muscle. I should be able to move the eye more medially with this hook. I am going to try to cut some of the surrounding connective tissue. Maybe that will free it up a little bit, but be careful you don’t get through the muscle itself. If you’re not sure, you can take a cotton tip applicator as I’m doing here and go along the edges first. There I can see the muscle behind it and now I’m going to trim a little bit more of the tenon’s capsule in the intermuscular membrane. We’re going to switch the hook over to the side for better control. If you’re not sure what you’re cutting, use the cotton tip to displace or remove scar tissue or connective tissue. Here, there’s a lot of connective tissue more than you would expect in a previously unoperated case, but that’s what it is. I’m not going to get too carried away with cleaning back on this muscle.
When the insertion is very tight like this, one of your options is to take a small hook and place it anterior to the large hook and pull it a little to spread the area. Then you will have a better opportunity to get your suture in the proper position. The inferior oblique insertion may be recognized. We’ll try to use the grooved muscle hook In this case, you can see there’s a groove in it and it’s reversible one so you can use it for either the right of the left eye. The grooved hook is preferable in a case like this where it could be very difficult to pass the suture without hitting the sclera with a needle attached to the suture. The grooved hook is also useful in cases of restricted thyroid ophthalmopathy, when the muscle may be extremely tight and difficult to elevate the eye from the sclera.
So I’m going to go right over the groove with the needle and stay within the muscle. I like to come out the edge if I can like this and then I’m going to retrieve it by securing the needle and passing my locking bite, with the protection of the grooved hook. You want to get pretty substantial locking bite for the security in a tight muscle. The locking bite needs to be perpendicular through the muscle and that’s a little bit more difficult with the grooved instrument, but it still can be done. Now you can take the other end of the double armed suture and overlap it a little bit.
I like to push the needle forward as far as you can, so that you don’t have to get involved with picking up the tip of the needle, which may dull it. When you pass it through the sclera, we would like to pull it all the way through to line that up a little bit better. I’m going to come in the groove again, taking a larger portion of the muscle than I normally do because of the tightness of the muscle. The next step is to disconcert the muscle and then we’re going to see if that frees up our restriction.
Always take small bites under direct visualization for two reasons. I want to make sure I’m not cutting too deep or not deep enough and I also want to make sure that I’m not cutting the suture. Let’s have a look at this lateral muscle, pretty much it’s inelastic. It’s not going away. I mean if I let it go, you’ll see it just stays in this position. It’s not a normal looking muscle. It looks very band like or like a cord. Now we’ll check the forced ductions and you can see that we can secure the globe at the insertion and you can move it where you need to. We do have options where to reattach the muscle. We could just pick a spot and let it hang back as far as we want. Wherever we do attach lateral Rectus muscle, we would be very unlikely to over-correct this lady with the surgery.
So I will place the sutures pretty far back and reattach it at a point in the sclera. Let it hang back as far as we can and that will probably make the most sense. You can see that the position of the muscle will not retract. I’ll reattach it around nine millimeters posterior through the insertion, but I’m going to let it hang back as far as it can. I have to engage the sclera and then get really flat. The tissue is very fibrotic, normally you can pass the needle easily. It’s not a large tunnel bite, but in this case I’m not particularly worried about it. She really has thin sclera, so we’re going to take our time to pass the needle. I just want to get enough to anchor it so I can tie a knot. Okay, let’s see, there it is. I’m still going to let it hang back, If it wants to. Usually do two one one throws with vicryl suture.
The conjunctiva is also going to be very tight and I may wait till we finished the surgery on the medial rectus muscle before we reattach the conjunctiva. Let’s work on the medial next and then we’ll come back to that. The large hook will be used to secure the medial rectus muscle, which is not as far back and should be easier to get. It’s located 5.5 millimeters from the limbus on average. We can tent up the conjunctiva tissue, which allows me to clean the muscle and visualize it better, using the small tenotomy hooks. It is still pretty tight, but it’s not as tight as the lateral was. So we will take another large hook and place it behind the muscle. I’m going to try to do about an eight millimeter resection and we can determine where to place the suture to secure the muscle. Using a little cautery to obtain hemostasis and you can see muscle very nicely. So there’s our caliper and we’re measuring the eight millimeters and we pass the sutures, similarly as we do in a recession within the tendon and come out the edge.
Next we’ll lock the suture. You must pass the locking bite perpendicular through the muscle, about one fourth from the edge or more of the muscle especially it it’s tenuous. You can either come from behind or from the anterior surface, whatever you’re more comfortable with. And here’s the locking bite. So I’m holding the two sutures together and I’m using the hook to protect me from cutting the sutures anterior to where the sutures are placed. Small bites again, to free up the tissue. Now we need to remove the tendon and muscle from the original insertion of the stump. We leave enough tissue to be able to grasp the insertion so that when we reattach the muscle, we’ll have a reference point.
Now when we pass these needles, I like to go very, very flat, right up close to the insertion and angle them toward the middle or centrally. You know that the sclera is thicker anterior to the insertion, so I come in flat and enter through the deeper anterior insertion to secure it. I like to check it, make sure it’s tight enough and that’ll hold, do the same with the opposite suture. Once again, create the tunnel, come out deep in front of the insertion and pull the sutures forward. It’s easiest sometimes to bring the eye toward the muscle when you’re doing a large resection in order for the muscle to be advanced to its proper anatomic position. In this case we’re tying it again once with a double loop and then two singles to secure the muscle.
Once we have it secured, we’ll then cut the suture and the muscle is in the position that we want. We will advance the conjunctiva slightly, I don’t like to bring it all the way up to the limbus because it then creates more bulk in that area and could give you a problem with it. So I let it hang back slightly, maybe a millimeter or so. In this case we’re attaching it with a single interrupted, 6-0 plain sutures, you can use a vehicle too. And same thing at the other end of the incision. Again, I like to let it hang back just a little bit because when the eye does go to its central position, you frequently have a problem with it overlapping the conjunctiva or the conjunctiva overlapping limbus. Now we’re going to go back to the temporal area, which we had not closed. And in this case, because of the longstanding tightness of the conjunctiva, I find that it’s easier to reattach it to the original insertion in this case, which can augment our effect, by using this conjunctival recession to attach it at the original assertion. And that’s it. You can see that we have closed the eye. I’m not concerned about the bare sclera there is temporally, which will usually re-epithelialize. You have to be aware of that when you go back on a reoperation that you could have a problem with getting your hook back in there. We did perform the same procedure on the other eye, and I thank you for listening.
June 11, 2018