The new-generation ring
While the initial model of the ring was composed of 4.0 polypropylene, the second generation of the version is made with 5.0 polypropylene, making it even more flexible, and easier to insert and remove from the eye. In fact, it is this ease of insertion and removal through small corneal incisions that allows surgeons to routinely perform FLACS through 2-mm corneal incisions – incisions small enough to remain watertight during the docking and laser phase of the procedure.
Just before inserting the second-generation ring, I like to inject a small amount of ophthalmic viscosurgical device (OVD) under the iris in the meridian perpendicular to the main incision. This helps to ease engagement of the lateral ring scrolls with the iris.
I regularly use the ring with appropriate patients and find that once I have made the 2-mm incision with the blade, injected the viscoelastic and implanted the ring, I can place my patient under the femtosecond laser, create the capsulorhexis, remove the cataract and implant the IOL – all through the same 2-mm incision. I prefer doing FLACS with the ring in place after I have completely filled the anterior chamber with dispersive OVD (Viscoat, Alcon).
Doing so perfectly maintains the chamber and protects the corneal endothelium during aspiration of lens fragments. Of course, the surgeon has to be sure that there are no air bubbles trapped in the OVD, as such bubbles may divert the laser beam and lead to an incomplete capsulotomy.
In some circumstances, the corneal tunnel may be too short, and when this happens, there is a chance that the wound may not self-seal as expected. In these situations, I place a single 10-0 nylon suture before docking to maintain the anterior chamber. However, I find that I need to use this additional step in no more than one in 15 cases.
When the procedure is completed and the IOL has been placed securely in the capsular bag, the ring is simply removed by disengaging the distal scroll first, followed by the proximal scroll. There is usually no need to adjust the lateral scrolls because they automatically disengage on retracting the ring.