Eyeworld

EW CATARACT 72 February 2018 Other iris expanders Commonly used iris expanders include iris hooks, the Malyugin ring (MicroSurgical Technologies, Redmond, Washington), the I-Ring (Beaver Visitec International, Waltham, Massachusetts), the Assia Pupil Expander (APX Ophthalmol- ogy, Haifa, Israel), and Omidria (phenylephrine and ketorolac injec- tion, Omeros, Seattle). Iris hooks or iris retractors come in many shapes and sizes. They are used to maintain a safe pupillary diameter during surgery when phar- macological dilatation is unsuccess- ful or in intraoperative floppy iris syndrome. The flexible polypropyl- ene retractors are inserted through four incisions made with a paracen- tesis blade and mechanically dilate the pupil at four points for maxi- mum visibility during surgery. They are secured by silicone stoppers and are easily removed from the eye. The Malyugin ring 2.0 comes in two sizes (6.25 mm and 7.0 mm) and is inserted through the main surgical incision. The device is roughly square shaped with a loop Expanding continued from page 70 in each corner, providing eight points of iris fixation, which render the pupil almost completely round. It is made of 5-0 prolene, which is thinner than the 4-0 prolene that made up the previous version of the device. The ring comes with an injector and specifically designed inserter tool for the surgeon's left hand to be used through a sideport, which fits through a 2 mm clear corneal incision. The I-Ring polyurethane pupil expander engages the iris through- out 360 degrees and creates a uniform circular opening 6.3 mm in diameter. The circular device has four corners to hold the iris in place and provide iris stability but are designed not to pinch into the iris. The corners have holes for Sinskey hook manipulation as well, which are made to protect the iris from possible hook damage. The I-Ring comes with a specialized injector and its insertion, placement, and removal can be performed one- handedly. The round, large pupil created by the device facilitates the capsulorhexis. The Assia Pupil Expander has a scissor-like configuration, expanding the pupil using two spring-loaded devices that are inserted through 1.1 mm sideport incisions. The blunt, curved tips are inserted through the pupil and behind the iris, and the specially designed forceps is gently released to allow the device to gain purchase of the iris. When placed symmetrically across from one another, the opening they create is rectangular, roughly 6 x 6 mm, or trapezoidal, allowing higher prox- imity to the surgical incision, if the devices are placed asymmetrically. The Assia Pupil Expander comes with two specially designed forceps. Device insertion, which is extraocu- lar and associated with less manipu- lation than rings, is a matter of a few seconds. Omidria is a drug based modal- ity for managing small pupils that takes a different approach to the problem. Omeros combines phenyl- ephrine 1% and ketorolac 3%, a pu- pil dilator and NSAID, respectively, added to irrigation solution during cataract surgery to avoid pupillary constriction during cataract surgery and reduce postoperative pain. The drug, which is best used in pupils that are at least 4.5 mm in diameter but no smaller, does not actively dilate the pupil but maintains dila- tation during surgery. Iris expansion devices are indis- pensable to eye surgeons to provide visualization and safety during cataract surgery. The Canabrava ring can be implemented in a variety of situations, making it a good choice for cataract surgery. EW Reference 1. Canabrava S. Efficacy of the Canabrava/s Pupil Expansion Device in Cataract Surgery With Small Pupils: The First 30 Cases. 2017. Retrieved from Clinicaltrials.gov, identifier NCT03206983. Editors' note: Dr. Canabrava has finan- cial interests with AJL Ophthalmic. Contact information Canabrava: sac@centrooftalmologicomg.com.br

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