 There are four major principles of ophthalmic surgery. One is that when you operate on the eye, you don't want to move the eye. The second is that when you insert and remove instruments, you want to minimally distort the wound. Because if you do, the viscoelastic comes out. The chamber collapses and you're not stable. Three, you want to be able to operate 360 degrees and not just temporarily. So you have to hold instruments and be thinking about how can I insert and remove instruments in a controlled manner 360 degrees. And four, you need to be gentle and respectful for the tissue. So you're not destroying tissue unnecessarily. So you have to know the anatomy. The first instrument we're going to talk about is an angle instrument. We'll call it a chopper. Now, when we manipulate with the chopper, we need to hold the instrument as a dart, not as a pencil. Pencils are held like this, darts are held like this. So in order to manipulate and have the most flexibility and control, we need to hold the instrument like a dart. So here we're going to illustrate going in through a side port incision. And remember, the side port incision, you can think of them as a tube. So if I want to put my instrument into this tube, I have to come in in the direction of the tube. I can't come in this way, right? If I go in here, I'm not going to enter the interior chamber as well as if I came in in the direction of the tube. So when I come with the instrument for all corneal incisions, I'm going to be coming in in the plane of the incision. I'm going to go in first, and then I'm going to be turned vertically. I'm going to be here now with holding the instrument with three fingers like a dart so that I can manipulate 360 degrees and especially subincisional. When you're doing subincisional, you have to be able to pivot on the wound and you have to manipulate the instrument this way so that you're pivoting on the wound. Again, I'm not moving the eye. If I want to go from here to here, I don't do it this way, I rotate the instrument. So I want to be able to do it in all different directions and I want to be able to use both hands. So again, I'm going to come in distally here, I'm going to turn vertically. Again, holding the instrument like a dart, I can manipulate 360 degrees and then subincisionally I can manipulate here. So again, coming out in the plane of the wound, again coming in here, sideways, going vertical. I'm holding the instrument so I'm not moving the eye, I can manipulate subincisionally as well as distally, just moving it. So if I held it like a pencil and I wanted to manipulate, I'd have to make this motion. Plus, I'm usually going to move the eye all around holding the instrument like this and it's obviously much more difficult to rotate in the same direction and the same amount holding the instrument this way versus holding it here. This is a lot more efficient. Okay, that's number one. Number two is a cannulated instrument, either saline or viscoelastic. Remember again that there's a non-dominant hand that's a fixational hand and then the functional hand. So I'm right-handed so I'm going to use my right hand to manipulate the syringe and my left hand to fixate. So if I was going to be doing a hydro dissection, I would come in again in the plane, the wound is made in a cornea like this so I need to come in in the plane of the wound. I am not going to come in this way because if I come in here, once I get in the wound, I won't be able to get to the other side of where I want to inject. So this is the wrong way to enter the eye. You need to enter the eye in the plane of the wound. Now, I usually hold the syringe in this way so I can manipulate the angle of the tip. So if I'm coming in here for hydro dissection, I can come in in the plane of the wound and all I need to do here is rotate it a very small amount and now I'm underneath the capsule and I can inject here, I can come back and inject here. Sometimes I come out, rotate the instrument 180 degrees, go in again in the plane of the wound, gently rotates on at an angle, inject, come over here and inject. So that's my hydro dissection in the plane of the wound using my left hand's fixation, right hand functionally. If we were to do, to be using viscoelastic, the principles are the same. I want to be entering the eye in the plane of the wound, right? I'm not going to come in here and I'm going to use my left hand, pronating here. So I'm going to be coming in, I want to go into the opposite end of the anterior chamber. I'm going to use my left hand, sometimes I can angle it a little bit this way, go all the way to the end, inject my viscoelastic and slowly come out in this position. I'm not lifting up, I'm not moving the eye, the eye doesn't move, I'm coming out in the plane of the wound. So that's instrument number two. Instrument number three is the cystotone. The cystotone, again, is used just like all the other instruments. We're holding it like a dart, we're not holding it like a pencil. And the reason for that is that we want to be able to not move the eye and we want to pivot on the wound. So the other principle is that wherever you want to hold the instrument while you're in the eye, you want to start with that hand position. You don't want to hold the instrument in a certain way first and then when you come up vertically you have to readjust. You want to start with the way you want to hold it. So I'm going to hold it like this. So when I go into the wound, I'm going to go in the plane of the wound. I'm going to come vertically and I'm going to do start my capsule rectus here and just move. I want to move a certain way halfway to the iris and I'm going to pull back and I can extend the rectus. So I'm moving, I'm not moving on either side, I'm trying to stay in the middle of the wound. That's very important. Oftentimes when you try to move the tip of the needle on the capsule from this position to that position, people move it in this direction. So they go from here to here to extend the rectus when it should be, I think, rotating the instrument without moving the eye. And then I'm going to come out through the plane of the wound inferiorly. The principle is very similar with the Ogawa Utrata forceps. Again, I want to hold the instrument in this position. I actually also, I move my whole chair over to the left because it makes it easier to make a 360 degree wound because my wrist doesn't bend this way. So again, I'll move from here, I'll move the chair a little bit to the left. Now I'm going to come in in the plane of the wound. I'm not changing the position of my hand in the plane of the wound. I'm going to come vertically and I'm going to grab my rectus here and rotate this 360 degrees a lot easier with my chair position moved a little bit to the left. Remember that when you use this instrument, this is the plane of the incision is here. So I want to open and close the instrument in the plane of the incision. If I go into the eye and I grab the capsule in this direction and I open the rectus here, I'm going to open the wound, the viscoles will come out, the chamber will collapse and I'm going to have to ask for more viscoles. So that's why you don't grab the tissue if possible and open the instrument in that way. You want to open the instrument in the plane of the wound. The principle is the same for INA. So you have an angled instrument and you want to be able to hold the instrument so that you can rotate the instrument for the INA here. You can get it under the capsule and rotate it over here. So you have to have a way of rotating the instrument at least 180 degrees while you're in the eye. So you're in here and you rotate your capsule here, here and you're on the other side. So you're holding the instrument like a dart. If you held it like this, the way that you would have to do, you'd have to turn your wrist all the way down here to grab an aspirate here and you actually would be almost unable to go to the other side without changing the position of your wrist. So that's why we hold it this way because you can see it's much easier. I can go easily 180 degrees away. The final principle is the principle of the needle and where you hold the needle. So all needles have a... I'm going to use this Allen wrench as an example. All needles have a... the suture comes in and it's swayed to the end of the needle and there's a round area of the needle here. So this is the area that you do not want to grab with your needle holder because if you grabbed it here, the needle would be able to rotate easily. Away from this round area of the needle, the needle becomes square and so if you're grabbing it with a smooth surface needle holder and you grab a square part of the needle then this needle will not torque within the needle hole. I hope that's been helpful. The four principles of a good surgeon are don't move the eye. We don't want to distort the wound with instruments entering and exiting the wound. We want to be able to operate 360 degrees and we want to minimally damage tissue. Thank you.