OCT 2012

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

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October 2012 EW RESIDENTS 101 present, the three-piece lens can be sutured to the iris or it can be scleral-fixated, either with sutures or fibrin glue. Prior to removal of the OVD, which would be done with the vitrectomy tip, the Malyugin ring would be removed. I place non-pre- served moxifloxacin into the ante- rior chamber in complicated cases. I also have a low threshold for sutur- ing corneal wounds in such cases. Alex W. Cohen, M.D. Assistant professor of ophthalmology, University of Oklahoma, Dean McGee Eye Institute, Oklahoma City Dr. Cohen: This is a tough but unfortunately not uncommon situation to be in while training resi- dents. Post-occlusion surge occurs when a nuclear fragment blocks aspiration of fluid from the anterior chamber while vacuum pressure is building up in the line. Despite advances in microprocessors, hand- piece resistance valves, and vacuum line tubing compliance, when the occlusion breaks free a rapid efflux of fluid occurs that will shallow the anterior chamber and can bring the posterior capsule toward the phaco needle. Some surge is unavoidable. The question then becomes where is your phaco needle pointing when the surge occurs. Often times I wit- ness trainees chasing after nuclear fragments or attempting to phaco out in the periphery under the edge of the rhexis. Obviously these are not safe maneuvers, and it is best to keep the needle in the center of the eye at or above the iris plane while engaging the ultrasound function. In this manner, if a surge occurs, the needle will not meet the posterior capsule. In this case, given that there is a large posterior capsular tear, vitreous prolapse to the wound, and a large amount of dense nuclear material still in the eye, I feel that options are relatively limited. One of the first things I would recommend here is to place a dispersive viscoelastic in the eye to act as a tamponade against further vitreous prolapse and pre- vent chamber shallowing. Dilute, preservative-free triamcinolone (1:10) can then be injected into the eye to stain the vitreous. While this is not necessary, it does help define the scope of the problem. In a residency training situation I have found it invaluable to demonstrate the presence and dynamics of the vitreous to the less experienced sur- geon. If there is a large amount of vitreous prolapse anterior to the capsular rupture or up to the wound, the next order of business is to begin vitreous cleanup. It is important to suture the main wound and then perform an anterior vitrectomy via watertight paracentesis ports. I would do this until there appeared to be no further vitreous anterior to the capsular rupture, and I would confirm this during the vitrectomy by placing triamcinolone in the eye again. In this case, the posterior cap- sular rupture appears to involve one- third to one-half of the capsule, and I would be very concerned about losing nuclear pieces. The surgeon can inject a dispersive viscoelastic in the area of the tear as well as under the lens material and prepare to con- vert to an extracapsular technique. The initial incision can be enlarged with a crescent blade and brought back toward the limbus, or a new scleral tunnel can be created in another portion of the globe, i.e., superiorly. The Malyugin ring may get in the way of the lens loop dur- ing nuclear removal, and therefore it may be necessary to switch to iris hooks at this point. This is depend- ent upon the size of the nuclear frag- ments that remain, the size of the Malyugin ring, and the apparent stability of the Malyugin ring as it is engaged to the iris. Once the appro- priate size wound is created, the lens loop can be used to remove the remaining nuclear material. This main incision should then be promptly closed and a thorough anterior vitrectomy performed with the aid of triamcinolone again. The next issue is what to do about placing a lens. If there is good anterior capsular support, a lens can be placed in the sulcus. If there is no capsular support, a posterior cham- ber lens can be placed via a variety of techniques. Of late, I have be- come fond of the "scleral glue" or "haptic tuck" technique that has been popularized by Amar Agarwal, F.R.C.S. Another option is to suture a CZ70BD (Alcon) or similar lens with eyelets along the haptics to the sclera under a scleral flap. A lens can also be secured to the iris, depend- ing upon surgeon preference. A more straightforward and perhaps quicker option is placing an anterior chamber lens. There is already a large incision from the extracap wound. Whatever the choice, the viscoelastic should be removed using the vitrectomy unit at the end of the case, acetylcholine placed to bring down the pupil and check for any vitreous strands to the wounds, and the incisions should be sutured closed to ensure the eye is water- tight. EW Editors' note: Drs. Beiko and Cohen have no financial interests related to this article. Contact information Beiko: george.beiko@sympatico.ca Cohen: Alex-Cohen@dmei.org Figure 1 Figure 2 Source: Thomas Oetting, M.D.

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