EyeWorld Asia-Pacific December 2015 Issue

18 December 2015 EWAP FEATURE If, however, the lens is sufficiently subluxated “there’s not enough real estate” to use the femto properly, Dr. Ahmed said. He also recommended referring weak zonule cases if the surgeon is not comfortable performing a capsulorhexis in those cases. Pearls for identifying zonular deficiencies Both Drs. Safran and Cionni recommended examining the patient in an undilated state, since dilation can “dampen the zonular laxity,” Dr. Cionni said. Once the patient is dilated, look for a scalloped edge on the capsular bag, and get “as wide a dilation as you can,” he added. “If you try breaking the capsule with your forceps and start seeing capsule wrinkles, or the lens moves a bit, that can give you a subtle tip that the zonules may be weak,” Dr. Ahmed said. During manual capsulorhexis, “look for capsule striae, look for the capsule to move during capsulorhexis,” he said. If there is anterior chamber depth (ACD) asymmetry preoperatively, or “if the eye goes out of focus constantly and you find yourself needing to focus up and down more frequently than normal during the case, this could also be a sign of weak zonules,” Dr. Henderson said. Dr. Ahmed said that in addition to ACD, a posterior chamber that’s deeper than normal may be a subtle sign of deficiency. Dr. Safran said he’s concerned not only about what is visible, but what’s not. “If there’s trauma and you see a 90-degree dialysis,” it’s likely “the rest of the zonules are compromised. I react more to what I feel during surgery than what I see prior,” he said. Intraoperative management If the lens is mobile during the capsulorhexis, start thinking about ways to mitigate potential complications, including the use of capsule retractors and capsular tension rings (CTRs). Dr. Ahmed advised placing CTRs or capsule hooks on or around the capsulotomy “if the bag is loose; here, in the case of a femto capsulotomy, if the capsule edge has a few areas that are weak as a result of micropunctures or misaligned laser shots, that can lead to a tear.” Dr. Henderson places CTRs often, but especially if there is more than 2 clock hours of zonular dialysis. She recommended using a 3-piece IOL and “places the haptic against the weak zonular area.” She said a 3-piece IOL’s haptics “are more rigid” than a 1-piece and therefore the zonular weakness is better distributed around the lens equator. It’s crucial not to stress the zonules to avoid making the dialysis worse, Dr. Safran said. “Put support in before you stress the system,” he advised, adding he uses capsule support such as capsule retractors early and holds off on placing a CTR until “just prior to inserting the IOL.” He “never puts in the CTR before completing phaco and the I/A portion of the surgery.” Dr. Safran prefers to use a 1-piece ZCB00 (Abbott Medical Optics, Abbott Park, Ill.) in the bag for most of these kinds of surgeries, coupled with CTR use and one or two sutured capsular tension segments (CTS). If he’s opting for intrascleral haptic fixation of the IOL, he prefers the Aaren EC-3 Pal (Carl Zeiss Meditec, Jena, Germany), and has moved away from optic capture with haptics in the sulcus to using suture supported segments as needed with the lens placed in the bag. He added that he has no reservation about using toric IOLs in these cases, provided that the bag is intact and adequate suture support with a CTS is created prior to completing the case. Dr. Cionni also prefers a single- piece acrylic lens “because it goes more easily through small incisions and through the capsulotomy,” he said, and therefore surgeons would stress the bag less. “Every OR” should have CTRs, iris hooks, and capsule retractors available, Drs. Ahmed and Cionni said. The MicroSurgical Technology (Redmond, Wash.) capsule retractor “has a special double-loop design that can be placed atraumatically in the capsule bag to support the capsule equator,” Dr. Ahmed said. Further, capsule retractors do not impede cortical aspiration, as might happen with a CTR. If there’s only a clock hour or so of dialysis to the lens equator, “you may not need to do anything,” Dr. Cionni said, “but when you have a lens that’s misshapen like that with only a localized area that has a scalloped edge to it, that means the area of dialysis is extremely weak, compared to the remaining zonules and therefore, managing the case may be relatively straightforward.” Placing rings too early in the surgery may lead to trapping cortex behind them, and if the dialysis is profound enough, Dr. Ahmed recommended retractors or CTSs (he invented the latter), reserving rings for cases of “moderate to severe zonular deficiency.” Also, the liberal use of viscoelastic surgery device (OVDs), “cannot be stressed enough,” Dr. Cionni said. A complete hydrodissection, and possibly hydrodelineation, will decrease the zonular stress. Dr. Henderson advised using a chopping technique to minimize the number of times the lens must be rotated. Her preference is to place hooks after the capsulorhexis to help “transform a difficult case into a manageable one.” Suturing Always be prepared to suture the ring in these cases, even if you don’t believe it will be necessary, Dr. Cionni said. “Usually we can salvage the capsular bag, so the real question becomes if there’s going to Zonular issues - from page 16