EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.
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April 2012 Phacoemulsification continued from page 19 www.AcrySofReSTOR.com CAUTION: Federal (USA) law restricts this device to the sale by or on the order of a physician. INDICATIONS: The AcrySof® IQ ReSTOR® Posterior Chamber Intraocular Lens (IOL) is intended for primary implantation for the visual correction of aphakia second- ary to removal of a cataractous lens in adult patients with and without presby- opia, who desire near, intermediate and distance vision with increased spectacle independence. The lens is intended to be placed in the capsular bag. WARNING/PRECAUTION: Careful pre- operative evaluation and sound clinical judgment should be used by the surgeon to decide the risk/benefit ratio before implanting a lens in a patient with any of the conditions described in the Direc- tions for Use labeling. Physicians should target emmetropia, and ensure that IOL centration is achieved. Care should be taken to remove viscoelastic from the eye at the close of surgery. Some patients may experience visual disturbances and/or discomfort due to multifocality, especially under dim light conditions. Clinical studies with the Ac- rySof® ReSTOR® The use of trypan blue improves visualization of the anterior capsule and helps make the performance of the anterior capsulotomy easier and more reliable Create PC buffer zone with OVD Early in the case, the large nucleus tends to hold back the posterior cap- sule. After much of the nucleus has been removed, however, there is an increased danger of injuring the pos- terior capsule with the phaco tip. Dense hypermature lenses have little epinuclear material with fragile floppy capsules that are easily drawn in to the tip. Toward the end of the phaco procedure, a dispersive OVD may be used to inflate the posterior chamber and push back the poste- rior capsule. The dispersive OVD re- sists aspiration, maintains distance between the pupillary plane and the posterior capsule, and helps to pre- vent injury to the capsule during the final part of the phaco procedure. Watch carefully for "lost" chips Very dense nuclei often break into many tiny particles that can get trapped in the eye during the phaco procedure. Care must be taken to look for and remove all the little chips that may be hiding in the an- terior chamber, in the incision, or in the iris. It's wise to re-enter the phaco incision with the phaco tip and to irrigate the side port(s) at the end of the case to free and aspirate chips that may be trapped in the in- cisions. lens indicated that pos- terior capsule opacification (PCO), when present, developed earlier into clinically significant PCO. Prior to surgery, physi- cians should provide prospective pa- tients with a copy of the Patient Informa- tion Brochure available from Alcon for this product informing them of possible risks and benefits associated with the AcrySof® IQ ReSTOR® IOLs. Studies have shown that color vision dis- crimination is not adversely affected in individuals with the AcrySof® Natural IOL and normal color vision. The effect on vi- sion of the AcrySof® Natural IOL in sub- jects with hereditary color vision defects and acquired color vision defects sec- ondary to ocular disease (e.g., glaucoma, diabetic retinopathy, chronic uveitis, and other retinal or optic nerve diseases) has not been studied. Do not resterilize; do not store over 45° C; use only sterile ir- rigating solutions such as BSS® PLUS® or BSS Sterile Intraocular Irrigating Solu- tions. ATTENTION: Reference the Directions for Use labeling for a complete listing of in- dications, warnings and precautions. Placement of a dispersive OVD to push back the posterior capsule and maintain the posterior chamber toward the end of the case helps prevent posterior capsular injury Source (all): D. Michael Colvard, M.D. to another location to finish the case. Protect the endothelium Phacoemulsification of the dense nucleus requires longer phaco times and higher energy levels. An en- dothelial protective dispersive OVD is desirable in these cases to help prevent endothelial injury. Care should be taken to perform as much of the phaco procedure as possible in the pupillary plane. Special care must be taken in hyperopic patients and others with shallow anterior chambers. Focus on disassembly of nucleus Chopping of a very dense nucleus can be difficult to accomplish ini- tially because of the leathery nature of the lens material. If a good crack through the entire nucleus cannot be accomplished with chopping ma- neuvers, I find it useful to convert to a "divide and conquer" technique. It is important to carry the grooves deeply enough to see a fundus reflex at the bottom of the groove. This al- lows one to make the deep cracks through the entire thickness of the nucleus, which are necessary to di- vide the nucleus completely. The "divide and conquer" technique re- quires more total energy than suc- cessful chopping techniques, but because the energy is delivered more posteriorly, this technique is gener- ally well tolerated by the endothe- lium. Once segments of the dense nucleus are freely mobile, chopping techniques can then be re-em- ployed. Be prepared: Capsular hooks, etc. And finally, be prepared for every- thing. The capsule and supporting structures of dense mature cataracts are always fragile. Even with the greatest care, these structures can be- come compromised during the pro- cedure. Make sure that you have capsular tension rings and capsular hooks available should the need arise. Conclusion Phacoemulsification of the very dense cataract presents the surgeon with a series of specific and difficult challenges. Successful management of these cases requires a thoughtful, step-by-step approach that antici- pates these challenges and allows the surgeon to surmount them. EW Editors' note: Dr. Colvard is clinical professor of ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, and director, Colvard-Kandavel Eye Center, Encino, Calif. He has no financial interests related to this article. Contact information Colvard: eyecolvard@earthlink.net © 2011 Novartis 8/11 RES11067JAD