Eyeworld

EW CATARACT 30 October 2017 Device focus by Michelle Stephenson EyeWorld Contributing Writer iris hooks in my practice. The only hooks I use are the capsular hooks that help me stabilize the capsular bag and sometimes maintain mydri- asis. These are patients with ectopic lenses and fragile zonules," he said. In cases where a stronger device is needed, Alan Crandall, MD, Salt Lake City, recommended the APX Ophthalmology Pupil Expanding Device (Haifa, Israel). "This provides quite a wide opening, but it can also be positioned in a location so that you have free access to your main incision, which is helpful," Dr. Cran- dall said. He also uses Grieshaber Flexible Iris Retractors (Alcon, Fort Worth, Texas) and MST capsular hooks. "Both are quite nice. The difference is that the Grieshaber hooks are a bit flatter and hold the iris slightly dif- ferently. The MST hooks have a large surface area, but it's a little harder to get them out as far as you want. I try to figure out what kind of iris the patient has, and what kind of visual- ization I need," Dr. Crandall said. "If you're visualizing to do the cataract, that's one thing. If you're visualizing to do the scleral fixation, that's a dif- ferent thing. If you're retrieving the lens from one part of the eye, I find that iris hooks are more appropriate. What I suggest is that you have an arsenal of these devices. You're not going to be using them very often, but it's nice to be able to fine-tune whatever you need to each individ- ual case. Some irises are flimsy and tear apart easily; in that case, you might want to use a thicker device, such as the Malyugin Ring." are for situations in which the pupil is extremely small and needs to be opened up incrementally or the pupil needs to be opened to a specific size. "If the iris is small and imperfect, you can't presume that it will dilate to 7 mm without tearing. For all else, pupil re-expanders have largely supplanted the area where pupil expansion is required. I would also point out that especially in teaching capacities, I think that the rings are more readily adapted by beginning surgeons and take less time to insert and retract than four or five iris hooks," he said. Dr. Kenyon prefers the I-Ring (Beaver-Visitec International, Waltham, Massachusetts). "It's a soft, polyurethane material that is gentle on the iris tissue. It is designed so that it can't possibly squeeze and hence tear the iris. Thus, I have found it to be not only useful in my own surgery, but in teaching. Beginning surgeons adapt to it more easily than any other device," he said. Boris Malyugin, MD, PhD, Moscow, Russia, prefers the Malyu- gin Ring (MicroSurgical Technology, MST, Redmond, Washington). "In some patients, the pupil is extremely small and possibly fibrotic, so it's a good idea to use a pupil stretching maneuver to expand it a bit. With that maneuver, you create the space in which the pupil expansion ring goes. This will help to insert the pupil expansion device much more easily. However, pupil stretching is not recommended for intraoperative floppy iris syndrome. If the pupil size exceeds 3.5–4.0 mm and the iris is not fibrotic, it is mostly unnec- essary. I personally see no room for Devices There are several pupil expansion devices on the market that deserve a look. "The ease of access and improved affordability of pupil expansion devices have allowed us to use them more frequently rather than resorting to the traditional iris hooks," said Ken Kenyon, MD, Bos- ton. "Certainly, it is inappropriate to do anything in the way of stretch- ing the iris, as was suggested in the past, because of the potential for iris sphincter tears." According to Dr. Kenyon, the remaining indications for iris hooks Both devices and pharmacologic agents should be in a physician's armamentarium P erforming cataract surgery in patients with small pupils can be a challenge even for the most ex- perienced surgeon, and inadequate pupil dilation can cause a multitude of problems. Pupil dilation can be achieved by using devices or pharmacologic agents. Update on pupil dilating devices Malyugin Ring 2.0 injected into the eye Source: Boris Malyugin, MD, PhD continued on page 32 Role of SLT in the world of MIGS Inder Paul Singh, MD, discusses how SLT can be a useful treatment in the management of glaucoma.

• Blank Page
• Blank Page (1)