EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.
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14 EW NEWS & OPINION February 2013 Tools & techniques Preventing the Argentinian Flag Sign: Phaco capsulotomy by Christopher C. Teng, M.D. M ost cases of phacoemulsi���cation in the presence of a mature white cataract can be performed without dif���culty following the creation of an intact anterior capsulorhexis. It is the creation of the continuous capsulorhexis that is the challenge in many of these cases. An intumescent bulging lens runs the risk of rapid tears to the lens equator developing once the anterior capsule is opened. This ���splitting��� of the anterior capsule can occur despite adequate anterior chamber formation with OVD but can usually be prevented by quickly decompressing the capsular bag immediately after puncturing its surface. One method of performing this decompression involves the use of a 25or 27-gauge needle that is used to open the anterior capsule and simultaneously aspirate lens material in order to alleviate outward stress on the anterior capsule. Another method utilizes the phacoemulsi���cation needle to perform the same maneuver. In this month���s column, Christopher C. Teng, M.D., presents an excellent review of the Argentinian Flag Sign and a step-bystep approach for performing phacocapsulotomy in order to prevent its development. I am con���dent that you will ���nd it a nice option for your next mature white cataract. Richard Hoffman, M.D., Tools & techniques editor T he Argentinian Flag Sign occurs during capsulorhexis construction. Due to the overbearing pressure of the cataract, the anterior capsule tears and extends to the periphery. Once this occurs, the remainder of the cataract extraction can become extremely difficult and can lead to many complications, such as posterior capsule rupture, vitreous loss, retained nucleus, and endothelial damage due to prolonged surgery time. Phaco capsulotomy is a technique in which the phacoemulsification tip is used to simultaneously create the initial tear in the anterior capsule and remove a portion of the intumescent lens, thereby debulking and relieving pressure from the lens and capsule, and preventing the Argentinian Flag Sign. Introduction White cataracts and intumescent cataracts are challenging cases for most surgeons. In these eyes, during capsulorhexis creation, the pressure created by the hyperhydration of lens fibers can cause spontaneous tears in the capsulorhexis that extend to the periphery. When this occurs, the appearance of the stained blue anterior capsule beside the white cataract mimics the blue-white-blue pattern of the Argentinian flag and was named the Argentinian Flag Sign (Figure 1). Daniel Mario Perrone, M.D. coined the term, and his video won awards at the 2000 American Society of Cataract & Refractive Surgery and the European Society of Cataract & Refractive Surgeons annual meetings. One method for preventing the Argentinian Flag Sign is by introducing a 27-gauge needle on a syringe into an intact anterior capsule. The needle is used to aspirate the liquefied cortex, thereby depressurizing the nucleus, which facilitates a controlled capsulorhexis.1 Additionally, a highly cohesive ophthalmic viscosurgical device (OVD) can be used to pressurize the anterior chamber against the pressure of the intumescent lens, which can facilitate continuous curvilinear capsulorhexis (CCC) completion.2 Alternatively, a CCC can be created using a twostage technique, which can help prevent unexpected radial tears.3 The phaco capsulotomy technique, which likely first originated in India, introduces the phacoemulsification tip through the center of an intact anterior capsule and aspirates a portion of the lens. This simultaneously creates the initial anterior capsule puncture and removes some of the liquefied cortex and nucleus. Phaco capsulotomy debulks and depressurizes the entire lens/capsule apparatus, and removes the impetus for the capsule to tear outward. Once enough of the cortex is aspirated, OVD is injected and a leaflet of the capsule can be grasped with a forceps, and the capsulorhexis can be completed without complication. Figure 1: Argentinian Flag Sign. Arrow indicates tear of the anterior capsule, which extends to the periphery Technique The initial steps are identical to a cataract extraction in which capsular stain is used. This includes creating a paracentesis, using a capsular stain, injecting highly cohesive and/or dispersive OVD, and creating a main wound. After the main wound is created, the phacoemulsification tip is introduced into the eye. The handpiece should not be irrigating upon entry, as there is OVD present in the anterior chamber that maintains anterior chamber form. The bevel of the tip should be positioned facing up, as this best facilitates removal of liquefied cortex and underlying nucleus. Next, the phacoemulsification tip should be directed at a downward angle and situated over the center of the anterior capsule. The settings on a torsional phacoemulsification machine should be in the sculpting mode, with no phacoemulsification power but high phaco handpiece torsion, low vacuum, and moderate aspiration. When the foot pedal of the phacoemulsification unit is depressed, irrigation and aspiration is introduced at a fixed rate. Various settings can be used depending on the phacoemulsification machine used. The next sequence of events occurs simultaneously. The foot pedal is depressed and the anterior capsule is punctured with the phaco tip. This creates the initial anterior capsule puncture, and the phaco tip is introduced into the lens (Figure 2A). Milky cortex will become visible and is quickly aspirated into the handpiece. The phaco tip is further embedded into the nucleus to sculpt the nucleus and further remove the milky cortex. This sculpting motion can be made repeatedly, with each successive motion removing more of the lens. Once the surgeon determines that enough of the cortex and fluid is removed, the phaco handpiece is removed from the eye. OVD is then injected to refill the anterior chamber and the nonuniform tear of the anterior capsule can be visualized (Figure 2B). Next, using a capsulorhexis forceps, a leaflet of the anterior capsule can be grasped, and the capsulorhexis can be completed in a curvilinear fashion (Figure 2C). Hydrodissection can then be performed and nucleus removal can be performed in the usual fashion. Discussion Phaco capsulotomy is an effective technique to debulk the lens and remove the impetus for the Argentinian Flag Sign to occur. The main complication that I have encountered using this technique is wound burn. This occurs when the phaco tip embeds immediately into the nucleus and occludes, leading to an interruption of aspiration. Wound burn can be effectively countered by pulsing the foot pedal upon entry of the phaco tip or by using burst mode. Pearls to performing this technique include using a second instrument and using a 2.75 mm wound and larger phaco tip. Eyes with mature intumescent lenses frequently have shallow anterior chambers, and