Eyeworld

32 | EYEWORLD | AUGUST 2020 by Liz Hillman Editorial Co-Director SKILL FOCUS ATARACT C A bout a year ago, Rosa Braga-Mele, MD, was teaching a resident how to avoid an Argentinian flag sign with a lens under pressure. She had done everything right. Then, about 90 de- grees into creating her capsulorhexis, the patient coughed, and the capsule ran into a "beautiful Argentinian flag sign." It was a different teaching case now. Care to avoid the Argentinian flag sign begins preoperatively. Dr. Braga-Mele said the obvious cases to be careful with include white cataract in a younger patient, traumatic cataract that has turned white, cases with bulging of the anterior lens capsule, cases showing a pupillary block-like syndrome, or cases with phacolysis syndrome. Jeewan Singh Titiyal, MD, said more subtle signs can be viewed at the slit lamp, too. "The presence of a shallow anterior cham- ber, increased convexity of the anterior lens capsule, and intralenticular fluid clefts in the anterior lens cortex are indicative of raised in- tralenticular pressure on slit lamp biomicrosco- py. In addition, fellow eye evaluation, especially if phakic, can provide useful clues regarding the anterior chamber depth and anterior capsule convexity," Dr. Titiyal said. Different etiologies might cause some white cataracts to have more pressure than others. Preoperative exam and anterior segment OCT or intraoperative OCT can help differentiate, Dr. Titiyal said. "We use intraoperative OCT to classify white cataract into four variants based on the morphological features and identify intumes- cent white cataracts with raised intralenticular pressure (ILP). 1 Type I cataract are characterized by regular lamellar cortical fibers with no fluid or clefts on iOCT; type II have hydrated swollen cortical fibers with multiple intralenticular clefts; type III have homogenous ground glass regions indicative of cortical liquefaction interspersed with intralenticular clefts; and type IV have ex- tensive liquefaction of the anterior lens cortex," Dr. Titiyal said. The classic Argentinian flag sign is asso- ciated with type II white cataract, Dr. Titiyal said, requiring "urgent decompression of the intralenticular pressure to prevent capsulorhexis extension." Regardless of the etiology, Dr. Braga-Mele said she treats all white cataracts as if they're under pressure. She always uses trypan blue to stain the capsule and relies heavily on a dispersive viscoelastic. Dr. Braga-Mele uses a 27-gauge needle on a 1-cc syringe that is half filled with balanced salt solution to decompress the lens through a small opening in the ante- rior capsule; a fluid-to-fluid interface is easier to pull back on than fluid to air interface, she said. She then fills the chamber tightly with the dispersive viscoelastic, and as she's piercing the anterior capsule, she's pulling back the plunger to remove any fluff or pressurized cortex. To preclude this step, Dr. Braga-Mele em- phasized giving "verbal anesthesia" when you puncture the anterior capsule and begin your capsulorhexis. "You want to ask the patient at that point to not cough, don't talk, don't move, because if they cause an increase of intra-abdominal pressure, that's a higher risk for an Argentinian flag sign, no matter how well you're doing in the anterior segment," she said. Dr. Braga-Mele said she starts small with her capsulorhexis. If she completes it, she'll go around again to make it bigger. Abhay Vasavada, MD, also uses an unbent 27-gauge needle through a 1-mm incision to puncture the capsule, sucking out the fluid with some balanced salt solution. "This is unlike the normal anterior capsu- lorhexis where we make a puncture with a bent cystotome and do a tangential movement to make the slit," he said, noting that if you were to do this, it would lead to peripheral extension. Dr. Vasavada said he'll use microincision forceps to hold a portion of the slit, pushing it further with the forceps to create a large opening with rounded ends that won't extend. From here, he enlarges the capsulorhexis. He also stains the anterior capsule with trypan blue in all white cataracts. In some cases, Dr. Braga-Mele said it's safer to employ an automated capsulorhexis device, Under pressure: Avoiding the Argentinian flag sign About the doctors Rosa Braga-Mele, MD Professor of ophthalmology University of Toronto Toronto, Canada Jeewan Singh Titiyal, MD Professor and head Cornea, Cataract & Refractive Surgery Services RP Centre for Ophthalmic Sciences All India Institute of Medical Sciences New Delhi, India Abhay Vasavada, MD Iladevi Cataract & IOL Research Centre Raghudeep Eye Hospital Ahmedabad, India

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