When I developed the Malyugin Ring (MicroSurgical Technology) as a means to ensure uniform dilation of the pupil and to provide circumferential protection of the iris, I did not realize just how popular the device would become. Yet, over the years, many of my colleagues have shared with me how frequently they rely on the device in both routine and challenging cataract cases.
I often hear from colleagues about the ease with which the Malyugin Ring can be implanted. I also hear, however, criticisms that the device cannot fit through a corneal incision smaller than 2.2 mm. This is true, unless the technically challenging wound-assisted injection technique is employed. In an attempt to create an even friendlier device, the original Malyugin Ring has been remodeled and reengineered so that it can be implanted through a smaller incision. Right now that incision size is 2 mm (Figure 1A), but, in the future, there is hope that it will fit through an even smaller incision.
AT A GLANCE
• The Malyugin Ring has been modified to enable surgeons to insert the device through a 2-mm incision.
• The new model is easier to implant and to remove than its predecessor.
• The enhanced flexibility of the device is friendlier to iris tissue compared with the previous version of the device.
The dimensions of the Malyugin Ring 2.0 are similar to those of the original device, with slightly smaller thread, the same scroll size, and a wider scroll gap.2 The ring is still supplied with its own injector, but the injector design is new, in order to allow the ring to be inserted more easily through the smaller incision (Figure 1B). The latest version of the Malyugin Ring is made from 5-0 polypropylene, which is thinner and more flexible than the 4-0 polypropylene of the original. The device continues to be available in diameters of 6.25 and 7 mm.
Tip No. 1. I have found it helpful to inject a highly viscous OVD such as Healon5 (Abbott) behind the iris at four points corresponding to the intended position of the scrolls on the iris margin.
Tip No. 2. When injecting the leading scroll, I position the injector tip close to the iris margin, in order to better control engagement of the scroll with the iris.
Tip No. 3. In cases of unexpected intraoperative miosis, the Malyugin Ring must be implanted after the anterior capsulorrhexis is created. In this situation, it is important to ensure that the ring is not engaging the anterior capsule margin. I have found that a technique I call the picture frame maneuver is extremely helpful. Using the sideport instrument, the ring can be displaced in any direction, much like moving a picture frame. Restricted movement in certain directions usually corresponds with areas where the scroll is catching the anterior capsule. Once this is recognized, I use the ring manipulating tool to catch the scroll and retract it toward the center of the anterior chamber, disengaging it from the iris and capsule. Then I can lift and position the ring back in contact with the pupillary edge. This technique can be repeated if more than one of the ring’s scrolls is catching the anterior capsule. I also use the picture frame maneuver to ensure correct positioning of the Malyugin Ring.
Tip No. 4. As soon as the IOL is positioned in the capsular bag, I remove the Malyugin Ring with a technique that I call the screwdriver maneuver. First, I introduce the ring manipulating tool through either the main or sideport incision. Second, once the ring manipulating tool catches one of the scrolls, I pull it toward the center of the pupil, then, lifting the scroll slightly, place it on top of the anterior surface of the iris. Next I rotate the ring counter-clockwise to disengage the next scroll. Once the newly released scroll is caught by the manipulator, I again rotate the entire ring counter-clockwise, releasing the next scroll. Once all scrolls are released from the iris margin, the Malyugin Ring will be positioned flat on top of the iris. I then use the inserter to remove the ring from the eye and completely remove the OVD from the anterior chamber.
USE IN LACS
The Malyugin Ring 2.0 can also be used in laser-assisted cataract surgery (LACS) to help combat the inflammation and subsequent pupillary miosis that can occur as a response to the laser energy. In some cases, pupil size can constrict to 3 mm after the applanation with the patient interface and during the initiation of phacoemulsification.
During LACS, when the pupil is not wide enough, I place the patient under the laser only after the Malyugin Ring is inserted. In such cases, ideally, the incision will be self-sealing and as small as possible to avoid chamber collapse in the time leading up to laser docking.