JAN 2013

EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.

Issue link: https://digital.eyeworld.org/i/104833

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Page 51 of 70

January 2013 EW RESIDENTS 49 Cataract M&M rounds Rhexis goes out late H ere we will discuss another case that presents a relatively common complication. We are fortunate to have three experienced cataract teachers to tell us how they would guide their charges through the rest of the case. We have also provided a link to the video showing how we moved forward with this case at the University of Iowa. The first 350 degrees of the capsulorhexis went fine. The tear was round and reasonably centered. An attempt was made to complete the rhexis by bringing the tear toward the center to complete the continuous tear (Figure 1). However, this maneuver was not complete, and when the presumably completely torn capsule was removed, the incomplete tear instead went radial under the wound (Figures 2 and 3). Now we are faced with a tough situation. We have a subincisional radial tear of the anterior capsule, prior to hydrodissection and with all of the nuclear material left. We asked our expert teachers: How can we minimize the risk of this radial tear continuing posteriorly during dissection of the lens from the capsule and during nucleofractis? What is the best strategy for IOL placement if we are able to get the nuclear material out without additional injury to the capsule? Thomas Oetting, M.D., Cataract M&M rounds editor Watch this video on your smartphone or iPad using your QR code reader. (Scanner available for free at your app store.) webeye.ophth.uiowa.edu/eyeforum/ atlas-video/Radial-tear.htm Kenneth L. Cohen, M.D. Sterling A. Barrett Distinguished Professor of Ophthalmology University of North Carolina at Chapel Hill, School of Medicine Chapel Hill, N.C. I f a late radial tear in the capsulorhexis occurs and cannot be rescued, the first step is to stabilize the anterior chamber. Stabilization of the anterior chamber reduces the stress on the tear, decreasing the chance for the tear to wrap around the equator to the posterior capsule. This is a twofold process. First, inject a highly cohesive ophthalmic viscosurgical device (OVD), Healon5 (Abbott Medical Optics, Santa Ana, Calif.). Second, after injection of OVD, insert the phacoemulsification needle and aspirate the anterior cortex and epinucleus. These maneuvers reduce the intralenticular pressure, which could force the capsular tear around the equator, through the zonules to the posterior capsule. With the anterior chamber stabilized, the next objective is to begin to safely dismantle the cataract in the capsular bag. Remember that the zonules attach around the equator to the anterior and posterior capsule and to the anterior vitreous. These attachments form a barrier to a wrap around extension of the tear to the posterior capsule. The forces pulling and pushing the radial tear peripherally are minimized. Thus, it is safe to perform gentle cortical cleaving hydrodissection and hydrodelineation. The cortex is separated from the capsule, and the nucleus and epinucleus are separated from each other. Now, the cataract must be safely emulsified. This should be done with minimal rotation of the nucleus. Chopping techniques use forces that do not place stress on the zonules. The dominant hand impales the nucleus and supports the nucleus anteriorly, away from the posterior capsule and the zonules. This prevents stress on the posterior capsule and the zonules from the chopper movements. The easily reachable nuclear fragments, 180 degrees from the incision, can be brought to the pupil for emulsification. Now there is room in the capsular bag, allowing the remaining nuclear fragments to be maneuvered to the pupil for emulsification, with minimal pressure against the equator of the capsular bag. A cohesive OVD helps to maintain space and minimize pressure on the equator of the capsular bag. Because there was hydrodelineation, the epinucleus remains in place, helping to keep the capsular bag open and protect the posterior and equatorial capsule. Once the nuclear fragments are emulsified, the epinucleus can be removed. Using flow and vacuum, the anterior rim of the epinucleus should be grasped 180 degrees from the incision. With a blunt second instrument in the non-dominant hand, the epinucleus can be flipped and emulsified and aspirated. Alternatively, the irrigation and aspiration handpiece can be used to aspirate the cortex peripheral to the epinucleus. As the cortex is aspirated, the epinucleus will also be stripped and folded to the center for aspiration. This will be a longer process than aspirating and emulsifying the epinucleus with the phacoemulsification needle. Especially in the presence of a radial tear in the anterior capsule, I like to use bimanual irrigation and aspiration through two 1.2 mm x 1.4 mm trapezoidal incisions to remove the cortex. A suture is placed, closing the main incision. A second sideport incision is created with the trapezoid blade. The irrigation and aspiration handpieces can be switched, allowing easy access to cortex in all locations. To keep the capsular bag open during removal of cortex, inject more cohesive OVD. The existing cortex also helps to keep the capsular bag open. Because the capsular bag is held by the OVD and cortex, the cortex at the radial tear is easily accessible and should be aspirated first. Collapse of the capsular bag increases risk for complications when removing the cortex in the location of the tear. Inject a cohesive OVD and remove the suture from the main incision. Now it is safe to inject a onepiece IOL, as the haptics are soft and will not open with a force that will extend the radial tear. Also, the cohesive OVD will hold the capsular bag open to help minimize stress. Ideally, the IOL should be rotated as little as possible to position the haptics 90 degrees from the meridian of the tear. Inject the leading haptic into the correct position in the capsular bag and then gently place the trailing haptic into position with a Sinskey hook. To ensure a stable anterior chamber during OVD removal, suture the main incision and use bimanual irritation and aspiration. Place one instrument on the IOL continued on page 50 Figure 1: An attempt was made to complete the rhexis by bringing the tear toward the center to complete the continuous tear.

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