Cristos Ifantides, MD, MBA, presents a combined iris defect and iridodialysis repair using modified sewing machine technique in a patient with some missing iris tissue.
Iridodialysis • Iris reconstruction • Suturing
I'd like to share a case of an iris defect and iridodialysfis repair that I did using modified sewing machine technique. Here you can see me make access points using a paracentesis blade, and then putting viscoelastic in the eye to try and straighten out the iris. I'm also using MST forceps here to try an reapproximate the iris, just to see how much tissue I have to work with.
The next step here is to use a CIF-4 curved needle, using a 10-0 Prolene suture, and using MST forceps, try and get this needle through non-atrophic areas of the iris. You can see I'm focusing the passes on some healthy tissue, and that's because I don't want to cheese wire through.
I then use a 27-gauge cannula to guide the needle in and out of the paracentesis. I'm now using a Maloney Manipulator to grab the distal portion of the suture and pull it out of this proximal paracentesis. To save time for this video, I'm just going to refer you to a great video that I used to help me master the modified Siepser sliding knot, and that's from Ike Ahmed on his YouTube channel. So if you just type in modified Siepser sliding knot for iris suturing, you'll see his video.
There are multiple different ways to repair the iris defect and the iridodialysis, including the order of operations. I've chosen to fix the iris defect first, and that was because I wasn't sure how much tissue I would be working with in terms of the iris. So I chose to repair the iris defect first before moving on to the iridodialysis repair.
One tip during this process is to limit the amount of traction you put on the iris tissue when you're fishing out your distal suture with your second instrument.
The last step is to go in with MST intraocular scissors and cut the sutures off of the knot. This was a large iris defect, and so I'm going to repeat the steps again going through another area of the iris, making sure to use healthy iris tissue, and close off the remaining portion of the iris defect.
I'm entering through the same paracentesis that I used for the first pass, and I'm also exiting using the 27-gauge cannula through the second proximal paracentesis, as you can see here.
A 3-1-1 modified Siepser sliding knot is repeated, just like we did with the original pass. Sometimes it makes more sense to reapproximate the iris tissue closer to the pupil and then move peripherally. In this case, the peripheral iris tissue was not connected to the angle because of the iridodialysis. I also knew that there was iris tissue missing based on the operative note from the cataract surgery. For this reason, I decided to start peripherally.
Once the iris defect was repaired, I moved on to the iridodialysis repair. I'm bending a 30 gauge, thin walled TSK needle and threading the remaining 10-0 Prolene suture through the bevel and out of the hub. This video makes the process look easy, but working with a 10-0 Prolene suture is challenging. Trust me when I say that I edited out some of the failed attempts.
I'm not creating a peritomy in the area where I'll be doing the modified sewing machine technique to repair the iridodialysis. After creating the peritomy, I use light bipolar cautery. I then dry the area and mark two millimeters from the limbus. I create a scleral groove using a crescent blade. This groove will be used to cover the suture so that there is no conjunctival erosion. I then make a paracentesis for the needle to enter the eye, and place more viscoelastic to flatten the iris.
I then introduce the 30-gauge needle with the 10-0 Prolene needle threaded through into the paracentesis I just made, and angle it towards the iris area where I want to reapproximate the iris into the angle. I advance the needle through the iris and then through the sclera, tacking the iris to the angle. One tip here is to give yourself plenty of redundant suture for the first pass. This allows for a loop to be pulled out after the needle tip is exposed outside of the sclera. It's much easier to work with a loop rather than a short tail that you have to fish out of the 30-gauge lumen.
When I first started doing this, I thought the suture would be cut by the sharp bevel of the needle, but that hasn't been the case. Make sure to pull out a healthy amount of suture out of the lumen to prevent the suture from withdrawing back into the eye when you withdraw the needle into the anterior chamber.
Once the needle is withdrawn, I angle the next piece of iris tissue a couple of millimeters away, and again advance it through the angle, aiming for the scleral groove.
Each time I go through the sclera, I grasp the suture and pull on it to create about a four millimeter loop in size.
I repeat this technique along the length of the iridodialysis, just like a sewing machine runs its course along a piece of fabric.
After the final pass, I carefully check to see which side of the loop is connected to the suture still threaded through the needle, and I pull it all the way through the needle to externalize it. This portion of the suture will be a suture tail for the knot.
I turn my attention back to the original suture tail at the beginning of the running suture. I carefully thread this tail through each loop I just made. This can get tricky, especially if viscoelastic is on the surface of the eye, so make sure to irrigate it before you do this step.
I tie a 3-1-1 knot and make sure that the entire suture sits nicely below the scleral groove. I decided against using any intraoperative diathermy to reshape the pupil, because in cases with iris tissue missing, I find it easier to wait and see how the iris heals before I reshape the pupil.
I'm closing the conjunctiva here with an 8-0 suture, and then irrigating all of the viscoelastic out of the anterior segment using a Simcoe cannula.
This is a retroilluminated preoperative photo showing the extent of the iris defect, and here's a photo from post-operative day one. The pupil isn't completely round, but with the extent of missing iris tissue, and a happy patient with resolution of symptoms, I counted this as a victory.
I hope you found this video helpful. Thanks for watching.