MALE SPEAKER: What I want to do is mark 7 millimeters for our temporary keratoprosthesis and then 8.5 for the permanent keratoprosthesis. So I'll do those all-- I'll find full thickness with the 7.25 once we mark the 8.5. What I'm doing here is a partial thickness incision along the 8.5 millimeter trephine mark. Now, we do a 7.25 millimeter trephination within that 8.5.
So far, we've just removed a 7 millimeter button of the host cornea and suturing on a 7 millimeter temporary keratoprosthesis. So for the keratoprosthesis, I like to go from the prosthesis through the host and then back from the host through the edge of the prosthesis, like so. And we can just do four of the sutures. One in each quadrant is enough to give you a watertight seal.
FEMALE SPEAKER: This is the edge of the keratoprosthesis. So, this would be about 3.5. I'm injecting balanced salt solution, but it is coming out here.
MALE SPEAKER: So, you see it right there is a little hole in the flange. And that's a source of leakage.
FEMALE SPEAKER: So, it seems looking at this retina that there is a lot of fibrosis. Here, you can see this would be the edge of an old retinectomy that was done. And I think the best case situation here would be to keep this as is and put silicone oil in the eye to prevent even further phthisis.
MALE SPEAKER: So, what we're going to do is first do an 8.5 millimeter trephination on the donor cornea. And we'll center that. Here's some of the culture medium. So now we're going to cut the donor with 8.5 millimeter trephine on the Hanna trephine system.
Now, the next step is to make a 3 millimeter punch in the center. So, there's our donor. Place the cornea donor on top of that.
So, this is a titanium back plate, 8.5 millimeters in diameter. All right. So, at this point, we're going to do is take off a temporary keratoprosthesis and then remove the peripheral rim of corneal tissue between the 7.25 and 8.5 millimeter trephinations.
So we want the edge of the donor roughly flush with the host. So, if I go very deep in the host tissue, then there's going to be underride because the host tissue is so thick. The challenge here is we've got a very small eye. So, I didn't want to do a real large trephination.
If we would, have gone 9.5 or so on the host, then we wouldn't have this problem. But because the trephine size is exactly the same size as the backplate and the peripheral tissue is so much thicker, it's creating a challenge in how the prosthesis wants to sit in the eye.
All right. So our 16 interrupted 9-0 nylon sutures are in. [INAUDIBLE] looks secure and the wound looks secure. I'm going to clip these suture ends. There we are. So we're just going to replace two of our knots, two of our sutures here.
FEMALE SPEAKER: So, here we see the final picture of how the retina looks. We're going to now fill the vitreous cavity up with air. And we're going to exchange for oil. So, as I inject the silicone oil into the cavity, the air is escaping up the infusion line.
And when we do an oil fill, we do want to make sure that it's not artificially filled. In other words, that we don't have a big air bubble but yet the oil is up here. So, I actually like to move the eye around to make sure that any air bubbles come up the tube as well.
I'm just making sure I get the first suture in here. If it needs a second one, we'll put that in. Remember, this is very friable sclera. So, we're going to use the infusion here. We're going to irrigate everything.
MALE SPEAKER: And pressure. I just don't want the pressure high. I think we're good. All right. We're good.
