EyeWorld Asia-Pacific March 2019 Issue

34 March 2019 EWAP CATARACT / IOL dialysis when iris retractors and conventional CTRs cannot fully stabilize the bag. The modified CTR uses an injector, and the device’s curved element easily slides along the equator of the capsular bag without damaging the capsule or expanding the zonular defect. It is fixated using scleral sutures. In the case of a patient with hereditary zonular deficiency, Dr. Malyugin proceeded with extreme caution from the start, as the capsulorhexis can be one of the challenging steps in these kinds of eyes. “I used a special hook here, an iris capsule retractor,” he said. “I allowed the edge of the hook to rest on the equator, not causing much stress on the edge of the capsule. This helped me perform the continuous capsulorhexis. I aspirated part of the cortical material and injected the modified capsular tension ring, making sure that I always inject the device toward the area of the zonular defect. As soon as it was in the bag, I needed to rotate the device to place the fixation element at the very center of the zonular defect, in order to replace the missing zonules. The fixation element was repositioned on top of the anterior capsule. Then the suture was passed through the ciliary sulcus. The residual cortical material was evacuated, and the IOL was implanted into the capsular bag.” It can be useful to inject triamcinolone into the eye to identify vitreous matter in the anterior chamber. If a vitreous prolapse is identified, vitrectomy is required. Dr. Malyugin proposed the use of a dry vitrectomy to not hydrate the vitreous, and apply viscoelastic to reposition it into the posterior chamber. “I use 9-0 polypropylene to fixate the eyelet of the CTR, which is partially retracted inside the injector tube, then I inject the device toward the zonular defect,” he said. “The reason for this is because when I have relatively healthy zonules in some areas, I take care to preserve the residual zonules and keep them from unzipping. It is also important to not press on the lens while injecting the CTR because in doing so you will induce the prolapse of the vitreous. Even with the modified CTR sutured to the scleral wall, the surgeon has to remember that vitreous can still seep through the zonular defect and excessive hydration of it should be avoided. “CTRs should be implanted as late as possible and as soon as necessary. The reason for that is because it compresses the cortical material to the equator and you can have a hard time evacuating cortical material during irrigation/ aspiration, which then takes much longer,” Dr. Malyugin said. “Insert them at the very beginning of the case, following the anterior CCC, or after capsular bag content evacuation. In eyes with generalized zonular laxity, use a combination of capsular tension segments (CTS) plus CTR, for instance the Malyugin CTR plus Ahmed CTS. In patients with zonular deficiency, be prepared for much longer surgical time and the right anesthesia, and do proper patient counseling. Finally, always have a backup plan because you cannot guarantee that the capsular bag will be intact or will be preserved during the surgery. I always ask my assistant to prepare not only a single-piece but also a three-piece IOL because I may have to change the plan and suture the lens to the iris or fixate it to the sclera.” EWAP Editors’ note: Dr. Malyugin has financial interests with Morcher (Stuttgart, Germany). Contact information Malyugin: boris.malyugin@gmail.com 9LHZV IURP $VLD 3DFLÀF CHEE Soon Phaik, MD Senior Consultant Singapore National Eye Centre 11 Third Hospital Avenue, Singapore 168751 chee.soon.phaik@singhealth.com.sg W eak zonules can be challenging. The site and extent of zonulysis, corneal status, presence of iris defects and vitreous in the anterior chamber (AC) should be examined for preoperatively. Ultrasound biomicroscopy can detect vitreous herniation behind the iris and demonstrates the lens size and its position when supine. These aid in planning surgery: capsulorhexis size and position, FDSVXODU WHQVLRQ ULQJ &75 VL]H DQG QXPEHU RI À[DWLRQ GHYLFHV QHHG for vitrectomy and iris repair. Note that developmental zonular weakness may result in a small and/or deformed undisplaced lens. Preoperative intravenous mannitol is helpful for an anteriorly displaced lens. The cause of zonular weakness predicts if zonulysis is static, e.g. trauma, or progressive, e.g. pseudoexfoliation. This helps in planning the number of À[DWLRQ GHYLFHV UHTXLUHG I prefer femtosecond laser-assisted capsulotomy. Certain lasers can center the capsulotomy on the scanned capsular bag and cut through vitreous in the AC. Manual capsulorhexis can be challenging especially in severe zonulysis. A cotton tip indenting the sclera to bring into view a hinged lens for access from a corneal approach facilitates the use of a 27-G needle to lance and levitate the lens. Capsulorhexis can be completed using micrograspers bimanually. The capsule is suspended E\ LULV KRRNV ZKLFK SURYLGH VXSSRUW DQG FRXQWHUWUDFWLRQ IRU VXEVHTXHQW capsule tearing. Where possible, the capsule should be torn from intact towards non-intact zonules. After capsulorhexis, iris hooks can be switched to capsule hooks to VXSSRUW WKH HTXDWRU RI WKH OHQV VDIH DOVR IRU IHPWRFDSVXORWRPLHV ,I vitreous is present, single-port pars plana vitrectomy with AC maintainer to cut anteriorly presenting vitreous stained by 50% diluted triamcinolone acetonide is appropriate at this stage, pulling vitreous posteriorly. In severe zonulysis, I insert a CTR early to further reduce tendency for vitreous prolapse. A cleavage plane between the anterior capsule and cortex is viscodissected before CTR insertion to avoid trapping cortex. Viscodissection in addition to hydrodissection helps to loosen the nucleus, minimizing zonular stress. One or two capsular tension segments (CTS) are inserted after cataract removal to provide the needed support, positioned to center the intraocular lens. I use Hoffman sclerocorneal pockets 1 which spare conjunctiva, important especially in cases with JODXFRPD (LWKHU SRO\SURS\OHQH RU SRO\WHWUDÁXRURHWK\OHQH *RUH Tex, off label for ophthalmic use) are appropriate for scleral suturing of device. The later suture can easily be used employing the suture VQDUH WHFKQLTXH 2 :KLOH PRGLÀHG &75V FDQ EH XVHG &76 DUH HDVLHU WR manipulate and add. References +RIIPDQ 56 HW DO 6FOHUDO À[DWLRQ ZLWKRXW FRQMXQFWLYDO GLVVHFWLRQ J Cataract Refract Surg . 2006 Nov;32(11):1907-12. &KHH 63 HW DO 6XWXUH VQDUH WHFKQLTXH IRU VFOHUDO À[DWLRQ RI intraocular lenses and capsular tension devices. Br J Ophthalmol . 2018 Oct;102(10):1317-1319. (GLWRUV· QRWH 'U &KHH LV D VSHDNHU IRU YDULRXV SKDUPDFHXWLFDO DQG RSKWKDOPLF VXUJHU\ GHYLFH FRPSDQLHV EXW KDV QR ÀQDQFLDO LQWHUHVWV UHODWHG WR KHU FRPPHQWV Compensating for zonular - from page 33