EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.
Issue link: https://digital.eyeworld.org/i/115557
March 2013 The first point is that the resident is having trouble maintaining the chamber during the case using a bimanual technique. Chamber instability during phaco represents an imbalance between inflow and outflow in the anterior chamber. Inflow is regulated by bottle height as well as potential problems with tubing (such as inadvertent kinking). Was the bottle height sufficient and the tubing checked when chamber instability was first noted? Outflow from the anterior chamber is controlled first by the aspiration flow rate set on the machine. Typically, if the aspiration flow rate is set too high there will be chamber instability. Secondarily, outflow is controlled by wound construction with potential contribution from the main incision as well as the paracentesis. If either incision is too large or is caused to gape during surgery then outflow will increase, resulting in chamber instability. The figure from the case shows that the paracentesis is gaping and/ or fluid is coming out of the paracentesis (even though there is no instrument in the paracentesis). It is likely that during the bimanual portion of the case, inadvertent outflow through the too-large paracentesis was increased, creating chamber instability. At this point in the case I would stop irrigating. Continued irrigation creates a Venturi effect at the paracentesis that will draw vitreous through the hole in the posterior capsule to the paracentesis. I would immediately reform the anterior chamber with a dispersive OVD through the paracentesis prior to removing the phaco needle from the eye. In this case where the hole in the posterior capsule is small, round, and central, if there is no vitreous present in the anterior segment I would open the bag with a dispersive OVD and inject a single-piece acrylic IOL into the capsular bag. One could also insert a three-piece IOL with the haptics in the sulcus and optic capture by the capsulorhexis as long as the rhexis is centered and smaller than the optic. Either method of IOL implantation would re-establish a barrier between the anterior segment and the vitreous cavity. After IOL implantation I would remove the remaining lens fragment by visco expression from the main incision. I am assuming that the hole in the posterior capsule occurred after most of the lens was removed from the bag. The risk of this complication is greatest when there is little or no lens material holding the capsule back and is typically a result of postocclusion surge (notorious with a EW RESIDENTS 125 peristaltic pump phaco machine). There are several ways to avoid this complication. Never bore completely through nuclear fragments continued on page 126 Your Eye Care Team's Resource for Online Ophthalmic Continuing Education Courses CE credits and courses brought to you by these trusted resources: $ QGHPDQGOHDUQLQJIRU7HFKQLFLDQV IIRUGDEOHDQGFRQYHQLHQW 2 1XUVHV3KRWRJUDSKHUV2UWKRSWLVWV QKDQFHVSURGXFWLYLW\DQGNQRZOHGJH ( 2SWLFLDQVDQG$GPLQLVWUDWRUV LGDFWLFDQGWH[WEDVHGFRXUVHV ' RSKWKDOPLFFRQWHQWDUHDVDQG LQWHUDFWLYHVLPXODWLRQVDXGLR RYHURQOLQHFRXUVHV FRXUVHVZHELQDUVDQGDVVHVVPHQWV For a FREE demo, visit: www.actioned.org