Title: Malyugin and I-Ring: Insertion and Removal
Authors: Troy Teeples MSIV, Nikko Ronquillo MD, Jeff Pettey MD
Photographer: Troy Teeples MSIV, University of Utah School of Medicine
Keywords/Main Subjects: Malyugin ring; I-Ring; cataract surgery
Brief Description: A pupil expansion device is an important tool used during cataract surgery in situations where the pupil dilates poorly, including floppy iris syndrome. Here we discuss the proper insertion and removal of both the Malyugin ring and the I-Ring.
Pupil miosis refractory to dilation protocols can shrink the surgical field of view and make phacoemulsification unnecessarily difficult. The use of a pupil expansion device is an effective way to increase the pupil size and enhance the surgeon’s field of view, thus making nucleus fragmentation and extraction both easier and safer. The Malyugin ring and the I-Ring have both proven to be safe intraoperatively, as they do not contain any sharp or pointed edges.
The Malyugin ring has four, equidistant loops which can ‘hook’ the iris and dilate the pupil to approximately 6 mm in diameter. Similarly, the I-Ring has four loops used for iris attachment; however, it has 360-degrees of iris contact, providing consistent pupil expansion without iris distortion. Both devices use an injector for insertion and removal through the main corneal incision.
Description of Technique:
Insertion of the Malyugin Ring: The insertion of the Maylugin Ring is performed using an injector through the main corneal incision. After the tip of the injector is inserted into the anterior chamber, the surgeon moves the thumb slide (located on the injector) distally to slowly inject the ring. As the ring is slowly inserted, the distal loop of the ring is attached to the iris, as seen in this video. Attachment of the lateral loops to the iris can sometimes be performed during this step but is not necessary. After the ring is completely inserted, the injector is removed. A Malyugin manipulator is used to position the remaining loops on the iris. In this video, the lateral loops are positioned first and the proximal loop is positioned last. This is done by grabbing each loop with the Malyugin manipulator and gently positioning the iris between the loop. Once all four loops are in position, the pupil is centered. Insertion of a Malyugin ring enlarges the pupil to 6mm in diameter.
Insertion of the I-Ring: I-Ring insertion is very similar to insertion of a Malyugin ring. The insertion device is introduced through the main corneal incision and the ring is injected by moving the thumb slider forward while gradually withdrawing the insertion device itself. A Sinskey hook is used to attach the ring via four positioning holes. It is suggested that the distal positioning hole is secured first, followed by the proximal hole and finally the lateral holes, as seen in this video.
Removal of Malyugin ring: Removal of the Malyugin ring is usually performed following intraocular lens placement. One the IOL is properly secured in the capsule, a Malyugin manipulator is used to remove the distal and proximal loops from the iris. As shown in the video, this is best accomplished by pulling the scroll to the left, following the curve of the ring. Once the distal and proximal loops are disengaged, the same insertion device is introduced into the anterior chamber and the thumb slide is moved distally until the hook appears. The hook is then used to pull the proximal loop into the insertion device. The Malyugin ring will fold back into the insertion device and can then be safely removed.
Removal of the I-Ring: The removal of the I-Ring follows the same basic concepts as the Malyugin ring, however it is not necessary to disengage the I-Ring from the iris before extraction. The insertion device is introduced into the anterior chamber. Using the thumb slider, the hook of the insertion device is allowed to engage the distal I-Ring, just lateral to the distal positioning hole. The I-Ring is then pulled slowly into the insertor allowing it to collapse on its own, following which the insertion device and I-Ring may be safely removed.
Faculty Approval by: Jeff Pettey, MD
Copyright statement: Copyright Teeples, ©2018. For further information regarding the rights to this collection, please visit: URL to copyright information page on Moran CORE
Disclosure (Financial or other): None