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EW FEATURE 72 Complex cataract cases October 2014 • Even with the sharpest choppers, penetration of a dense nucleus can be difficult calling for a change of technique to approaches such as stop-and-chop, divide-and-conquer, or small incision cataract surgery. • When cracking a dense nucleus, practitioners must be careful about being overly aggressive with lateral separation, as this may result in a rent in the capsule. • From making fluidics adjustments in dense cataract cases, phaco parameters may also need to be adjusted. by Maxine Lipner EyeWorld Senior Contributing Writer tachments between the 2 fragments, there is no need to apply further lateral motion," he said. These lenses will not conform to the confines of the capsular bag. "An over-aggressive lateral separation of the two fragments could potentially result in a capsular rent," Dr. Page said. If the lens is so dense that you cannot safely pass a chopper through, Dr. Page recommends making a quick groove and then rotating this 90 degrees and mak- ing a second one. This becomes the divide-and-conquer technique. Some surgeons prefer to use a nuclear cracker device. "The advan- tage of using a cracker is that it has 2 paddles that can align with the groove and provide an alternative technique to separate the 2 hemi- spheres," Dr. Page said. When removing these dense lenses, he modifies his phaco power from a maximum of 30 and a pulse setting of 40 pps, with a 50% duty cycle up to a 65% duty cycle. This Once in the operating room, Dr. Page may treat the dense cataract case a bit differently, modifying his phaco technique and power settings during the process. "In my experience, even the sharpest choppers will have some difficulty penetrating a dense lens, causing the lens to wobble on the phaco tip," he said. This stress may put the patient at risk for zonular dialysis, he noted. Instead of using his usual quick-chop technique, Dr. Page switches to either a stop-and-chop or a divide-and-conquer approach. With the stop-and-chop technique, Dr. Page creates a groove until he sees a glimmer of a red reflex at the bottom of the groove. "Then I know I have gone deep enough that I can crack it," Dr. Page said. He advises practitioners to place the needle and chopper at the deepest point of the groove. At that depth, he recommends slowly separating the two instruments in a lateral fashion. "Once the surgeon sees a clear red reflex without a - macula is limited at the slit lamp," he said. Preoperatively, if he cannot view the retina, the patient is sent for a B-scan ultrasound to rule out retinal detachment or tumor, he explained. With dense cataracts, subopti- mal scans can sometimes occur on the IOLMaster (Carl Zeiss Meditec, Jena, Germany). "If the primary spike is blunted or if the baseline is significantly elevated, careful atte - tion must be paid to the individual scans provided by the IOLMaster," Dr. Page said, adding that if the signal-to-noise ratio is less than 1.5, an error message will occur. Scans of 1.6 or higher will register, but still it is important to see at least 3 scans within 0.02 mm of each other. "If these criteria are not met, our biom- etrist will recognize the problem and perform an immersion A-scan," Dr. Page said. Fortunately, intraoperative wavefront aberrometry, which is done aphakically, has largely taken away the burden of having a suboptimal preoperative biometry. Cracking the dense cataract code How to tackle such cases D ense cataracts are not just found in the developing world. In the U.S., these still occur with a preva- lence that is remarkably high in some populations, according to Jeff H. Pettey, MD, assistant professor, Moran Eye Center, Univer- sity of Utah, Salt Lake City. At his urban Salt Lake City practice, Dr. Pettey finds these only occur about once a month; at the homeless clinic where he also works, there can be as many as 2 to 3 cases each month out of a pool of around 30 overall. "We're also doing work in the Navajo Nation where the pathology we're seeing is tragically similar and sometimes even worse than what we're seeing on trips to the developing world," Dr. Pettey said. From altering phaco fluidics to changing lens removal techniques, tackling dense lenses requires finesse. The following are some successful approaches to these difficult cases Mastering dense lenses For Timothy P. Page, MD, professor of ophthalmology, Oakland Univer- sity William Beaumont School of Medicine, Rochester, Mich., han- dling dense cataracts starts during the office visit, where he explains the added risks of dense cataract removal. "I tell [patients] there could be prolonged swelling of the cornea, and I explain that the view of the AT A GLANCE Dense cataracts are frequently found in some populations, including even in the United States. Source: Jeff H. Pettey, MD continued on page 74