Journal of Pediatric Ophthalmology and Strabismus

Eye to Eye 

Instructing Residents in Strabismus Surgery

Patrick A. DeRespinis, MD; Kammi B. Gunton, MD; Scott E. Olitsky, MD; Rudolph S. Wagner, MD

Abstract

Wagner: Our topic is instructing residents in strabismus surgery. Dr. Gunton and her colleagues recently published an article in our journal on the impact of a strabismus surgery course for first- and second-year ophthalmology residents. In this article, they pointed out that the trend for accreditation in residency programs is to require residents to demonstrate surgical proficiency rather than just understand the theory. The training model they developed involved using chicken breasts to simulate the intraocular muscles and to provide an ex vivo laboratory for the residents to practice in. They received positive feedback from the residents. Dr. Gunton, have you seen any improvement in the training of residents since you developed the course?

Gunton: We have the advantage of also having the first-year residents in the operating room with us when we're treating actual patients. But sometimes when you're trying to demonstrate a technique, it is easier to demonstrate on the chicken breast and have them understand exactly what you're doing in regard to the position of the hands. With a real patient, you're not going to throw a suture twice to be sure they can see it. I think the greatest impact I've seen practically is that they understand better what I am explaining to them in the operating room.

Wagner: The course you developed was not a long course and it was offered only one time.

Gunton: It's a 2-hour course. There's a didactic session in the beginning to talk about surgical complications and some of the reasons behind the techniques that we use, and then the rest of it is demonstrating on the chicken breast. Another advantage is that you can have them practice throwing the sutures for the horizontal muscle with the dominant right hand, but then turn the chicken breast so the muscle is on the other side and have them do it in a more awkward position.

Wagner: A pediatric ophthalmology rotation is often the first opportunity to experience real surgery before residents start doing intraocular surgery themselves, so we are often the ones training them to hold instruments.

Olitsky: We are also often the ones who show them how to tie knots. They don't use sutures for cataract surgery anymore.

Wagner: What sort of assessment was used to score the residents?

Gunton: We had a regular assessment that was generic for all ophthalmic surgery, but there is an ophthalmology surgery competency assessment rubric that essentially lists every step in strabismus surgery. I recommend using that because you can determine whether residents are able to complete each step and grade their competency on a scale of 1 to 5. Then the residents receive constructive feedback on the areas they need to improve.

Wagner: During your teaching career, have you modified your own surgical techniques to make it easier for the residents to understand?

DeRespinis: I try to break the procedure down into single components. Where do you hold the suture? Where do you hold the needle on the needle itself? What's the position of your hands? Which hand do you move and which hand do you try not to move? Residents look at what you're doing as complex, but it's really just individual tasks that you put together to make a uniform incision and closure. I haven't changed anything significantly over the past few years. I've just noticed that I can make it easier for them to understand by showing each individual component.

Olitsky: We have an attending physician take the residents through the steps before they go into the operating room. It's also a great time to show them the consequences of…

Wagner: Our topic is instructing residents in strabismus surgery. Dr. Gunton and her colleagues recently published an article in our journal on the impact of a strabismus surgery course for first- and second-year ophthalmology residents. In this article, they pointed out that the trend for accreditation in residency programs is to require residents to demonstrate surgical proficiency rather than just understand the theory. The training model they developed involved using chicken breasts to simulate the intraocular muscles and to provide an ex vivo laboratory for the residents to practice in. They received positive feedback from the residents. Dr. Gunton, have you seen any improvement in the training of residents since you developed the course?

Gunton: We have the advantage of also having the first-year residents in the operating room with us when we're treating actual patients. But sometimes when you're trying to demonstrate a technique, it is easier to demonstrate on the chicken breast and have them understand exactly what you're doing in regard to the position of the hands. With a real patient, you're not going to throw a suture twice to be sure they can see it. I think the greatest impact I've seen practically is that they understand better what I am explaining to them in the operating room.

Wagner: The course you developed was not a long course and it was offered only one time.

Gunton: It's a 2-hour course. There's a didactic session in the beginning to talk about surgical complications and some of the reasons behind the techniques that we use, and then the rest of it is demonstrating on the chicken breast. Another advantage is that you can have them practice throwing the sutures for the horizontal muscle with the dominant right hand, but then turn the chicken breast so the muscle is on the other side and have them do it in a more awkward position.

Wagner: A pediatric ophthalmology rotation is often the first opportunity to experience real surgery before residents start doing intraocular surgery themselves, so we are often the ones training them to hold instruments.

Olitsky: We are also often the ones who show them how to tie knots. They don't use sutures for cataract surgery anymore.

Wagner: What sort of assessment was used to score the residents?

Gunton: We had a regular assessment that was generic for all ophthalmic surgery, but there is an ophthalmology surgery competency assessment rubric that essentially lists every step in strabismus surgery. I recommend using that because you can determine whether residents are able to complete each step and grade their competency on a scale of 1 to 5. Then the residents receive constructive feedback on the areas they need to improve.

Wagner: During your teaching career, have you modified your own surgical techniques to make it easier for the residents to understand?

DeRespinis: I try to break the procedure down into single components. Where do you hold the suture? Where do you hold the needle on the needle itself? What's the position of your hands? Which hand do you move and which hand do you try not to move? Residents look at what you're doing as complex, but it's really just individual tasks that you put together to make a uniform incision and closure. I haven't changed anything significantly over the past few years. I've just noticed that I can make it easier for them to understand by showing each individual component.

Olitsky: We have an attending physician take the residents through the steps before they go into the operating room. It's also a great time to show them the consequences of not doing something correctly because you're obviously not going to show that on the live patient. I haven't changed my technique much, but I rely less on an assistant and I like the residents to do that as well. When they are operating on their own, they are not going to have an experienced attending physician showing them how to find an inferior oblique muscle or how to do a resection. I try to train them to be more independent.

Wagner: Some consider the most difficult part of strabismus surgery to be reattaching the muscle to the sclera, especially if you have a small child with a small eye in a thin sclera. Some who teach strabismus surgery encourage the use of a hang-back technique rather than passing the scleral suture in. In my opinion, if you're going to train them to be a good ophthalmologist, especially a pediatric ophthalmologist, I think they need to know multiple techniques and locations of passing the suture. What is your approach?

Olitsky: I have used the hang-back suture for most of my career, so I train residents with it because that's the way I would do it. It also allows me to do most of the surgery without an assistant.

DeRespinis: I was trained to only use a hang-back suture when it was necessary because of the ability to reach that particular area. I usually put scleral sutures in. It can be more challenging when you're dealing with a new resident who has never put in a scleral suture before. I am careful to explain how to grasp the needle and be deliberate in passing the suture, but I feel more confident when I put the muscle in its place and know that it's right there. I'm not sure what will happen after the healing process begins where that muscle is swaying from one side to the next, and I just feel more comfortable that way.

Gunton: There are times when it's appropriate to suture the muscle to the sclera in the location that you want and there are times when you need to use the hang-back approach. I think residents need to know both methods. I have the luxury of having fellow attending physicians who use the hang-back technique and others who don't, so our residents get exposure to both methods and I don't need to teach them a technique that I am uncomfortable using.

DeRespinis: That's true for me also. There are two physicians in my resident program. I use direct or scleral attachment almost exclusively and the other surgeon uses only hang-back sutures.

Wagner: Do you mostly use limbal incisions or do you use fornix incisions with the residents?

Gunton: I like to use the fornix-based incision, which I believe results in good cosmesis afterward for the patients.

Wagner: I do more of my lateral muscles through the fornix incision because I think it looks and heals better. I do the medial muscles through a limbal incision because I think it's easier, especially when you're training a resident. With a smaller eye, it provides better exposure and it's a little easier to visualize what you want to do. But I think it can be done either way.

DeRespinis: I also like exposure on the limbal incision. On the lateral muscles, I tend to use the fornix and cul-de-sac sutures because sometimes I'm also doing the inferior obliques or the lateral rectus and I will go through the same incision.

Olitsky: I use fornix-based incisions for most patients. I will use limbal-based incisions for some adults with very thin conjunctiva or reoperations.

Gunton: I think we should teach residents how to manage when the exposure is not ideal. You can show them how the size of your initial limbal incision can influence how much exposure you get and how repositioning the forceps and holding the insertion so that you can get more exposure posteriorly can help you. I would use that situation as a teaching moment.

Olitsky: That's a good point. I will sometimes demonstrate that opening the fornix incision slightly can be more comfortable for a novice surgeon.

Wagner: Do you have loupes when you operate?

Gunton: Yes, I do.

Olitsky: I do.

DeRespinis: I do also.

Wagner: Do you require the residents to wear them?

Olitsky: Yes.

DeRespinis: I prefer them to have loupes. I usually tell them to buy a pair that attach to glasses and are relatively inexpensive because the actual optics are pretty good.

Wagner: One of the issues that I've encountered with some of the residents is that they buy loupes with magnification that is too high and I think that makes it more difficult to operate. I prefer a 2× wide field.

Gunton: In our training course, we have some of the loupe vendors bring sample loupes in and the residents can try on different loupes. The vendors like it because they have potential sales and the residents like it because they get to see different magnifications and different working distances.

Olitsky: Residents should realize it's an investment in their future and their career. I have heard residents talk about how expensive loupes are, but they aren't all that expensive. If you can afford a new smartphone, you can probably afford a good pair of loupes.

Wagner: I recently created a video of eye muscle surgery being performed and I ended up using a microscope to operate for the first time. There was a bit of a learning curve, but the visualization was good. It made it easier to see the scleral depth, the sutures, and the tunnel created. At a meeting I attended in Albany, there was a presentation on using the microscope for strabismus surgery, which surprised me because I don't think most people use it.

Olitsky: I think it is mostly used in other countries where they can't afford loupes but they have an operating microscope. I've used the microscope in other countries so that other physicians who don't have loupes can observe and see with magnification what I am doing.

DeRespinis: When I was being trained at Manhattan Eye and Ear, one of my instructors was Dr. Veronneau-Troutman and she almost exclusively did her eye muscle surgery using the microscope. I found that it added an extra hour to the procedures. I think the microscope is helpful if you're trying to preserve the anterior ciliary circulation, but I haven't noticed the results being superior in terms of the actual procedure being done that way.

Gunton: I have not used the operating microscope, but one of the things that I stress to the residents is that you're not always in your loupe field, whereas if you're using the surgical microscope I think you would always be in the magnified field. For example, there are times when you're tying the suture around the needle that you are outside of your loupe field. I think it would make it slower, but I don't have any direct experience.

Wagner: When I was producing this video, I used a three-dimensional (3-D) microscope camera because they wanted people to be able to visualize the surgery in 3-D, which provides excellent images. Some retinal surgeons operate with a 3-D microscope camera with the heads-up position, meaning they wear goggles and look at the monitor while they're doing their retinal surgery.

Olitsky: We have some anterior segment surgeons and pediatric ophthalmologists who do 100% of their work with heads-up 3-D cameras. I've done it for strabismus surgery. It's a little awkward at first, but it works well for the primary surgeon. The difficulty is that your assistant is turned 90 degrees, so it's awkward for the assistant. If you are able to do strabismus surgery without an assistant, it works well and it's much better for you from an ergonomic standpoint.

Wagner: I think that's one of the reasons the retinal surgeons started using it. They were constantly bending over to look at the microscope and we know ophthalmologists have issues with this. It's almost like robotic surgery in a way. You're not looking directly at what you are doing or where your hands are.

Olitsky: It's a much more natural position. I would say it's a much healthier way to operate.

Wagner: Are you able to adapt to the visualization images well?

Olitsky: Yes.

Wagner: Do you predilate the patients when you do surgery with the resident?

Gunton: My standard pre-operative procedure is to put a drop of phenylephrine in the eye because it shrinks the conjunctival vessels and the eye is therefore dilated at the conclusion of the surgery. I don't routinely perform a dilated fundus examination unless there is something that occurred during the case that makes me suspicious.

Wagner: Sometimes when the residents do the preparation, they put so much betadine in the eye and the inflammation is so intense that you can't visualize properly.

DeRespinis: I also use phenylephrine when the eye is inflamed and I need to get rid of some of these vessels.

Wagner: Exactly.

DeRespinis: One other thing I have noticed when teaching residents is that if I use a traction suture and the residents place that traction suture at the 7- and 11-o'clock positions instead of the 6- and 12-o'clock positions, it completely throws off the anatomy. It seems like they don't even know where the muscle is anymore. So I try to stress to the residents that from the very beginning of the procedure it is critical to properly position the traction suture. Otherwise, it will rotate the entire eye.

Wagner: I could show each of you four different muscles and not tell you where they are, and you would probably be able to identify them correctly based on your experience. But an inexperienced surgeon is not as certain.

DeRespinis: Right.

Wagner: Thank you all for sharing your experiences on this topic.

Authors

Patrick A. DeRespinis, MD, is from Staten Island University Hospital, Staten Island, New York.

Kammi B. Gunton, MD, is from Wills Eye Hospital, Philadelphia, Pennsylvania.

Scott E. Olitsky, MD, is from the Department of Ophthalmology, Children's Mercy Hospitals and Clinics, Kansas City, Missouri.

Moderator: Rudolph S. Wagner, MD

The authors have no financial or proprietary interest in the materials presented herein.

10.3928/01913913-20180821-02

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