The SOS Basic Strabismus eye is being used here to practice how to make a safe scleral pass, of the appropriate depth with a spatulated 6/0 vicryl needle. Trainees can practice making passes in different directions with the needle forward and reverse mounted, getting a feel for the resistance and depth of the sclera.
In addition to Cybersight, you can find videos featuring teaching techniques for all types of ocular surgery, using any form of simulation, in the Simulation Gallery.
In this video, we will look at basic surgical skills for trainees about to embark on strabismus surgical training. And here we can see the needle being grasped correctly, but this is how not to put a pass through the sclera. Tips down and going too deeply, we’ve penetrated through the sclera, choroid, and the retina. So the first thing I teach trainees is how to make use of the spatulated needle by pressing backwards against the sclera, the tip of the needle engages safely in the sclera, and it’s easy to judge the depth of your scleral pass. And the second thing is to turn your wrist round, grab the needle, two thirds from the tip, and then you’re ready to go with your next pass. It’s very easy just to pull the needle through. But then you have to spend time remounting the needle for each pass. So here we can see again the tip just being engaged by pressing posteriorly on the curve of the needle, and the correct depth is achieved. The wrist is turned round. So you’re grasping the needle this time too close, actually, to the end of the needle to have full control. The next thing I get them to practice is making incisions which are parallel with the limbus. Here again the same principle of engaging the tip by pressing backwards against the sclera, twisting your wrist round, and note by using the basic eyes — and in this model jig, there’s no nose and eyebrow to get away, and no conjunctiva and no Tenon’s, so the trainees can practice this technique over and over again at home, until they get comfortable with the basics of needle handling and making scleral passes. Here we have again the reverse mount technique. So holding the needle correctly and pressing downwards onto the sclera, and getting a nice safe scleral pass of the appropriate depth. Again, twisting your wrist round and ready to go with the next bite. And by doing this, when trainees come to live surgery, they feel very comfortable with suturing in different angles and in different positions. The next thing I get trainees to do is to practice suturing with their left hand. Because there are situations during many forms of surgery where suturing left-handed is advantageous. So here again, just engaging the needle at the appropriate depth. Many left-handed people find it relatively straightforward to suture right-handed. There are definitely more ambidextrous than right-handed surgeons. But with practice, suturing and using other instruments with your left hand can become second nature. And spending evenings at home with the model eyes and practicing means that trainees can very quickly progress on to live surgery. Here again, just a left-handed pass being done parallel to the limbus. The next stage is to practice knot tying. A simple reef knot, using the instruments here. So a double throw is passed around the needle holder. Tip of the suture grasp. And then the suture is laid flat on the sclera. Just slightly out of focus there. And then wrapping it round the opposite direction and laying it flat again to create a reef knot, and finally, a third single throw. And this is the very basic knot tying, which needs to become second nature before attempting live surgery. And of course, the suture can then be just cut out, and the whole process repeated. >> Spatulated tip flat on the sclera and gently depress it. Do not angle the tip of the needle down towards the globe, or you will perforate. The needle should be seen through the sclera, throughout its pass. Once the tip is engaged, gently slide the tip forward by rolling the needle holder between your thumb and forefinger. If the bite is too shallow, the suture will pull straight out. As shown here, grip the needle ready for the next pass. Here the needle is being correctly held just beyond halfway. The needle tip is gently depressed flat on the globe. And a small bulge of sclera is being raised by the pass of the needle, which can be seen through the sclera, along the pass length. The needle is gradually pushed far enough so that can be regrasped beyond its tip, ready for the next pass. Again, this pass is not too deep, because the needle can be seen through the sclera, along its length. With the suture lifted here, you can see the brown of choroidal pigment shining through the sclera. This does not necessarily mean perforation, but clear fluid or blood is a bad sign. >> These live surgical videos have been taken from the publication Strabismus Surgery, which Peter Davis and I co-authored in 2007, but the videos are in their original HD format, which wasn’t available with the original DVD that accompanied this book.