Try reloading this page, or reviewing your browser settings
This video shows how to suture the graft onto the host cornea. Various suturing techniques including interrupted and continuous sutures are discussed as well as techniques to prevent post-operative astigmatism.
- diseased cornea
- donor cornea
- cardinal sutures
- refractive error
- long suture loops
- graft-host junction
- RK marker
- aligning sutures
- graft suturing
Conflict of Interest
The authors declare that they have no conflict of interest.
- 1.Jacob S (2018) Mastering DALK—a video textbook on deep anterior lamellar keratoplasty. Slack Inc, New JerseyGoogle Scholar
About this video
- Soosan Jacob
- First online
- 12 July 2019
- Online ISBN
- Springer, Cham
- Copyright information
- © The Author(s) 2019
This video discusses suturing of the graft onto the host cornea. Once the Descemet’s membrane is removed from the graft, it is placed onto the bed of the host. And the first cardinal suture that anchors the graft in place is taken at 12 o’clock
This is followed by the second cardinal suture at the exactly opposite meridian. That is 6 o’clock, again followed by the nasal and the temporal cardinal sutures. These four cardinal sutures are crucial to apply in the right way, with an equal distribution of graft on either side of opposite sutures in order to be able to get a well-placed and well-opposed graft at the end of surgery.
While taking these cardinal sutures, you can see that I have kept the anterior chamber moderately filled. This helps to flatten out any refractive error that these keratoconic patients have, as most of these corneas are very ectatic to start out. And they are highly myopic secondary to the deep anterior chamber. And therefore, not having an overfill of the anterior chamber while applying the sutures helps to take care of the refractive error also, to some extent.
Now, you’ll notice that after the first four cardinal sutures, I take the next four bites continuously, leaving long suture loops in between the four bites. And then I use these suture loops to tie down the knots and then cut the sutures to thus give separate, interrupted sutures.
It is not necessary to follow this technique. I just do it to save time. You could just pass each of these interrupted sutures one by one and thus come to eight interrupted sutures. Alternately, you can take four interrupted sutures and then follow this up with continuous sutures directly.
Now, just for the viewer’s attention, I will intermittently play the next section of video at a faster speed to optimize video time while still retaining interest and enhancing understanding.
I then take a 16-bite continuous suture. And you can see that the first bite of the continuous suture goes through the junction of the graft and host. That is, a bite is taken only through the host cornea. And then 16 bites are taken, one very close to each of the interrupted sutures and one in between each interrupted suture, giving a total of 16.
Now, this is done in a continuous fashion. And when you’re taking bites in DALK, it is important to take them deep enough, as superficial sutures can lead to a loosening of the sutures and suture-related issues in the post-operative period. It is also important that your bites are not so deep that they accidentally rip the residual pre-Descemet’s and the Descemet’s membrane on the host side.
The last bite of the continuous suture comes out at exactly the same spot where the first bite had gone in, except that it comes out again through the junction of the graft and host, going through only the graft this time. Now, when you tie down the knot, this allows the knot to go into the graft-host junction. And it can easily be buried by rotating the knot.
You would also have noticed that once the continuous sutures were placed, I went around and tightened the sutures from either side towards the 12 o’clock before tying down the knot in order to get the right suture tension at the end of the case. There was some blood that had oozed into the anterior chamber from the paracentesis, and that is washed out at this point.
Now, I fill up the anterior chamber and take the Maloney’s intraoperative keratometer and assess the intraoperative astigmatism. You can see that the mires are flattened in the vertical direction. To adjust which, I loosen the sutures superiorly, as well as inferiorly, to decrease the amount of induced astigmatism.
We check the mires once again. And you can see that it’s perfectly circular now, letting us know thereby that the amount of induced astigmatism from the suture is minimal. These can also be adjusted in the early post-operative period, as well.
Now, the combination of eight interrupteds and 16 continuous running sutures would depend on the surgeon’s individual preference. You could also use four interrupteds and a continuous running suture. Or you could just put plain interrupted sutures alone.
The other thing you could also do is to use a 16-blade RK marker to mark the graft, as well as the host, in order to be able to more accurately align your sutures.
For those interested in more information about deep anterior lamellar keratoplasty, further reading section, as shown above, is suggested. I do hope you enjoyed watching this video. Thank you so much.