Wagner: We have a typical case of a V pattern esotropia. A child presents with a primary gaze alternating esotropia of 35 prism diopters that reduces to 15 prism diopters in up gaze and increases to 40 prism diopters in down gaze and a significant symmetric inferior oblique overaction. There is a normal amount of hyperopia and the esotropia is the same at near and distance. You’ve decided that surgery is the correct option for this patient and there’s no refractive error that needs to be corrected or amblyopia that needs to be treated. Describe the amount of medial rectus recession you would do and then we’ll discuss your preferred choice of procedure for weakening the inferior oblique muscles.
Young: I would operate for 35 prism diopters and would recess each medial rectus 5 mm.
Strominger: I would also consider medial rectus recession and then I would look at the amount of V pattern he has and how many prism diopters difference it is between primary position and up gaze. Twenty diopters is significant and you probably want to address that, although the age of the child will play a factor. My approach might be different for a younger child than for an older child. For a 1 year old with congenital esotropia, even with this degree of V pattern, I might not operate on the inferior obliques at this point because sometimes addressing the horizontal deviation will alleviate the V pattern disparity. It also can be more difficult to measure in a child that age, relying more on Krimsky test measurements rather than cover–uncover test measurements.
Wagner: Would you consider transposing the insertion of the medial rectus muscle in a case like this with a V pattern where you don’t operate on the inferior obliques?
Strominger: I think it’s certainly reasonable to transfer it almost a whole tendon width downward if you’re not going to operate on the obliques at this stage.
Young: That’s an interesting point about not operating on the obliques now, thinking that recession of the medial rectus muscles alone in a young child may treat the V pattern. That may be true, although that has not been my experience. If there were moderate to severe inferior oblique overaction, my own practice is to recess the inferior obliques at that time. Regarding weakening the obliques in older children with a V pattern and not in younger children, it would seem to me that if the older ones need it, the younger ones would as well.
Strominger: That’s true, but many times the inferior oblique overaction in an older child tends to be more manifest and the parents notice it more, so that probably affects why I wait to do the inferior obliques.
Wagner: That definitely holds true. Some surgeons will operate on a patient with congenital esotropia at an early age, such as 6 months. Others hold back because they believe the oblique overaction might become more obvious with age and defer the primary surgery until the patient is a year old. In this case, let’s say you decide that you need to weaken the inferior obliques. What is your preferred weakening procedure?
Young: I do a one-size-fits-all inferior oblique recession and so I recess 3 mm posterior and 2 mm temporal to the temporal border of the medial rectus insertion. If that proves insufficient and there’s residual inferior oblique overaction after that, I’ll do an anterior transposition, but I find that the initial recession adequately corrects a significant range of inferior oblique overaction.
Wagner: Does symmetry affect your decision?
Young: Even if the inferior oblique overaction appears asymmetric, if there’s at least some inferior oblique overaction bilaterally and no significant hyperdeviation in primary, then I’ll recess the obliques symmetrically.
Wagner: Dr. Strominger?
Strominger: I’ve changed my thinking on this over the years and now do anterior transposition. I have patients who underwent inferior oblique recessions 12 to 13 years ago who develop dissociated vertical deviation (DVD) and more inferior oblique overaction as they get older. Maybe it’s the size of the eyes expanding so the relative position of the inferior oblique isn’t as recessed as you think. So now I’m primarily doing anterior transpositions on those children. Otherwise, you have to go back and anterior transpose the obliques that you had recessed previously or you have to do superior rectus recession. So my primary procedure would be anterior transposition and I would do it in both eyes.
Wagner: Dr. Young, if you have a case where you thought there was a combination of inferior oblique overaction and DVD, would that modify your procedure?
Young: I would absolutely do the anterior transposition.
Wagner: I originally did the inferior oblique recession until I learned the anterior transposition approach and started switching to that. I use the presence of DVD as an indication for anterior transposition. Some surgeons have reported great success comparing inferior oblique recessions with myectomy.
Strominger: I know many surgeons who would do myectomy in those cases.
Young: You mean with DVD?
Strominger: Even in this particular example. If you have 4+ inferior oblique overaction with a V pattern esotropia, they’re going to operate on the inferior obliques and do myectomies at the same time. I also know surgeons who would recess the inferior obliques on a patient who does not have a V pattern that’s significant at this point, thinking that at some point in the future the patients will have inferior oblique overaction and so they do that as part of their primary procedure. I don’t necessarily do that.
Wagner: Experience has shown that you can get good results doing different procedures on this particular muscle. It seems to be what I call a self-adjusting muscle. I think symmetry is important. I think you’re more likely to have difficulty with asymmetry, especially with the anteriorization. When I first learned how to do the inferior obliques, we were doing the 2 and 3 mm and then the 14 mm recessions became popular where you put it back in the inferotemporal vortex vein. That’s how Parks used to teach it originally. When I first started, they were even doing denervations and extirpations. Have you seen that procedure used?
Young: I’ve seen it, but I don’t use it. I haven’t found the need for it in my practice. A procedure that’s interesting but I also don’t have any personal experience with is nasal myectomy described by Stager for persistent recalcitrant inferior oblique overaction. Do you have any experience with that?
Strominger: I have no experience with it either. I have seen cases who years ago were having their inferior obliques operated on through an inferior eyelid incision. When I’ve gone in to look at what happened, a lot of those fibers ended up attached in unusual positions so then I try to anteriorize, recess, or myectomize whatever is left over.
Wagner: When you do the anteriorization, what is your preferred position to place the inferior oblique tendon?
Strominger: I put it 1 mm anterior to the lateral border of the inferior rectus muscle and I don’t spread it out. I try to keep it the same with the normal anatomy of the inferior oblique.
Wagner: They talk about anti-elevation syndrome, which can occur following malpositioning of the inferior oblique in these procedures, and I think it’s a real phenomenon. The farther you go from the inferior rectus and the more you spread it, the more likely you are to get problems with this. Do you ever do any asymmetric procedures where you might advance one a little more?
Strominger: Not usually.
Young: Let’s say someone has bilateral inferior oblique overaction, much bigger in one eye than in the other, and in fact does have a hyperdeviation with greater inferior oblique overaction in the hypotropic eye. In that situation, I would recess the less overacting one and anteriorly transpose the more overacting one.
Wagner: I’ve had situations when a patient has a particular asymmetry in their overactions or DVDs and did different amounts of recession or anteriorization in the two eyes.
Young: I’d like to ask both of you about slanting the insertion. I have no personal experience with that and it intrigues me.
Wagner: I don’t. If I have a large V pattern where there’s a significant esotropia in down gaze, I may inferiorly place them and that’s all I’d do. Sometimes I’ve done it along with inferior oblique recession because there’s a large difference between the up and down gaze.
Strominger: If I’m not going to do the oblique, I would consider that. If I’m going to do the oblique, I don’t.
Wagner: I think it’s interesting to look at this subject because there have been changes in the approach to the inferior oblique. Sometimes the trend reverses and you’ll see more surgeons doing recessions than they have done previously. Fortunately, I think if you have experience with the condition you can choose the right procedure for a particular patient and in most cases you’ll be successful.