Cataract surgery in patients with small pupils can be a challenging situation for surgeons.
Inadequate pupil dilation during cataract surgery can lead to serious intraoperative complications, such as iris damage, bleeding and prolapse, intraoperative floppy iris syndrome (IFIS), anterior capsule damage and potential misalignment of the IOL.1
Cataract surgeons have access to a range of surgical tools and devices that help to reduce the risks associated with small pupils, such as the Malyugin Rings (Microsurgical Technology). I have used the Malyugin Ring Classic and Malyugin Ring 2.0 in my operating room since they first came to the market. The latest device is the Malyugin Ring 2.0, so I will refer to this model in this article.
The Malyugin Ring 2.0 is a useful device in managing inadequate pupil dilation, which may occur in patients with conditions such as chronic uveitis, IFIS, glaucoma, pseudoexfoliation syndrome, diabetes mellitus, and idiopathic cases in the elderly.
Predictable is good
The classic Malyugin Ring design allows for insertion through a 2.2-mm incision. The next-generation device-the Malyugin Ring 2.0-is made from 5-0 npolypropylene, which is thinner and more flexible. The change in material enables placement of the Malyugin Ring 2.0 through a 2-mm incision. Designed by Boris Malyugin (Professor of Ophthalmology, Deputy Director General at the S. Fyodorov Eye Microsurgery State Institution) to avoid the disadvantages associated with some pupil expanders-such as potential overstretching of the iris sphincter or extended surgery time, the 2.0 also comes packed in a pre-sterilised single-use holder containing the ring and inserter, and is available in two sizes: 6.25 mm and 7.0 mm.1,2
The Malyugin Ring is as effective as traditional pupil expansion devices (such as iris hooks) but causes less stress to the iris tissue and is easier to
implant and remove. The device is placed through a main incision, thus eliminating the need for extra incisions.3
Benefits of the Malyugin Ring 2.0
The Malyugin Ring 2.0, with a diameter of 6.25 or 7.0 mm, is inserted through the main corneal incision, thus reducing surgical trauma and minimising mthe risk of contamination and postoperative inflammatory reaction. In the traditional technique, when the square pupil is formed by the conventional iris retractors, the iris can prolapse through the wound.4
The Malyugin Ring eliminates this complication. The ring is inserted and removed from the eye with the inserter, reducing the risks of contamination
and disturbance of the incision’s architecture and wound integrity.4 You can insert and extract through the standard cataract incision and larger spacing is offered between the anterior and posterior scrolls, allowing easier engagement and disengagement from the iris. There is no need to expand the incision when using the next generation Malyugin Ring 2.0, a time-saving benefit of this device.
It is square in shape and has four circular scrolls with eight points of contact with the iris that ensure an evenly dilated circular pupil is achieved.5
Accuracy like this is accredited to the ring’s dynamic development in terms of safety and flexibility. The single-use ring is as effective as other conventional iris hooks; however, compared with other commonly used iris retractors, it is friendlier to the eye due to its welldistributed stretching, gentle holding
of delicate iris tissue, and the easier and less traumatic implantation. It has no sharp or pointed endings that can damage the eye;4 also, because it
is a single-use instrument, there is no damage, it is sterile, and it ensures a new clean tool every surgery. The main disadvantages of iris nretraction devices include bulkiness and rigidity, making them difficult to insert, remove, and manipulate through a small incision. These devices are difficult to position if the anterior chamber is shallow or the pupil is less than 4 mm wide.6
Therefore, a gentler and less traumatic tool that is highly effective at maintaining adequate dilation of the pupil, disposable, safe and has elasticity is without a doubt more beneficial in cataract surgery.
Moreover, iris hooks can lead to postoperative optic captures of the IOL because of the damages to the iris tissue during the surgery caused
by excessive stretching.
Indications for use
I use the Malyugin Ring 2.0 in all small pupil cases. When there is a risk of the pupil becoming small during surgery, as with IFIS syndrome, I use the Malyugin Ring.
If the pupil is 6 mm or smaller it can be very stressful surgery, and this device makes it more comfortable and less stressful. The Malyugin Ring
2.0 is highly effective for small pupil cases.
I keep the Malyugin Ring 2.0 in the operating room for when I might need it. I had a case where I was unaware that IFIS could occur in the first eye. I managed it as best as I could, but was prepared for the second eye. By using the Malyugin Ring 2.0 it became a much more relaxed and comfortable surgery and this situation is a good indication for the 7-mm diameter ring.
Clinical study: the evidence
A study by Wilczynski et al.7 aiming to evaluate the results of phacoemulsification in eyes with a narrow pupil dilated with the Malyugin Ring, in comparison with manual pupillary stretching with hooks was carried out at the Department of Ophthalmology, Medical University of Lodz, Poland.
Two groups were studied, group one consisted of 23 eyes of 23 patients whose pupils were dilated using the Malyugin Ring. The second group consisted of 17 eyes of 17 patients whose pupils were dilated manually by stretching with hooks. The study concluded, in eyes with narrow pupils, the use of the Malyugin Ring makes the surgery easier and allows for better functional results and lower corneal endothelial cell loss in comparison with manual pupillary stretching with two hooks.
The Malyugin Ring 2.0 exhibits very predictable intraoperative behaviour. For me, it has taken the most complicated cataract surgeries and transformed them into normal cases. My operating room is now a less stressful place, with safe and comfortable surgeries-and that can be attributed to the Malyugin Ring 2.0 and its simple technique that makes complicated small pupil cases easier and safer.
The Malyugin Ring 2.0 is a low-profile, easy-to-use, time-saving device that has made cataract surgery a calmer and gentler experience for both surgeon and patient alike.
DR ARIE DANAN, MD
Dr Danan is affi liated to the Pierre Cherest Clinic, Neuilly sur Seine, Paris. He did not indicate any proprietary interest in the subject matter.
1. Malyugin, B. The Malyugin Ring in FLACS. The Ophthalmologist. Available at: https://theophthalmologist.com/issues/eye-robot/
2. Malyugin, B. Inserting the Malyugin Ring. Eyeworld.org. Available at: https://www.eyeworld.org/article-insertin
3. Osher, R Experience with the next-generation Malyugin Ring. Eyeworld.org. Available at: https://www.eyeworld.org/experience-nextgeneration-malyugin-ring
4. Malyugin, B. The Malyugin Ring: Dealing with Small Pupils in Phaco. Ophthalmology Management. May 2009. Available at: https://www.ophthalmologymanagement.
5. Schweitzer, C. Managing complications using the Malyugin ring. Feb 26, 2018. Ophthalmology Times. Available at: http://www.ophthalmologytimes.com/ote-articles/managing-complications-using-malyugin-ring
6. Malyugin, B. Malyugin Ring for Small Pupil Phaco Cases. Cataract and refractive Surgery Today. Available at: https://crstodayeurope.com/articles/2008-mar/0308_18-php/
7. Wilczynski, M., Wierzchowski, T., Omulecki, W. and Synder, A. Results of phacoemulsification with Malyugin Ring in comparison with manual iris stretching with hooks in eyes with narrow pupil. European journal of ophthalmology 23(2)· October 2012. DOI: 10.5301/ejo.5000204· Source: PubMed. Available at: https://www.ncbi.nlm.nih.gov/pubmed/23112041