MAR 2014

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

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Page 130 of 210

E W SECONDARY FEATURE 128 by Ellen Stodola EyeWorld Staff Writer Innovation in capsulorhexis Evolution of the technique P hacoemulsification has changed the way that cataract surgery is done, as has the technique of creating the capsulorhexis. Thomas Neuhann, MD, medical di- rector and the founder of the Laser E ye Center Munich, Germany, and Howard Gimbel, MD, Gimbel Eye Centre, Calgary, Alberta, Canada, are two surgeons widely credited with creating the technique of the capsu- lorhexis. They discussed the contin- uous curvilinear capsulorhexis (CCC) and how it has changed since its creation more than 20 years ago. Inventing the technique Dr. Gimbel explained that the in- vention of this technique relates largely to the evolution of the cap- sule opening. It had evolved from Charles Kelman, MD's "Christmas tree" tear, which was a triangular opening, to additional radial cuts rather than one big cut. The cuts became smaller and smaller, and it was called the can opener technique, he said. However, there were still V-shaped nicks all around that had the possibility to tear out, which created the risk of the nucleus going into the vitreous during phaco. The possibility of radial tears in the anterior capsule was the incentive to find a new technique. There was a motivation to make the long tears contiguous so there was no V-shaped opening, and Dr. Gimbel said that starting in 1984 he joined multiple concentric tears, al- ways joining them from outside the circle. "If it's a blunt joining of two tears, there's no propensity for it to radicalize," he said. He added that with viscoelastics, one continuous tear around the whole circle was facilitated. Until 1983, the majority of sur- geons placed the IOL in the ciliary sulcus, while others preferred place- ment in the capsular bag, Dr. Neuhann said. "The controversy at that time was whether placement in the bag had enough advantages to accept its disadvantages, namely fre- quent dislocation of one haptic out of the bag." In 1984 others began to look into the advantage of capsular bag placement, however there were some disadvantages like an "unac- ceptably high occurrence" of asym- metric haptic placement in and out of the bag. "In analyzing what the reasons for this could be, I found that while intraoperatively both haptics were in the bag, the one haptic that postoperatively was out of the bag was associated with an adjacent tear in the capsulotomy," Dr. Neuhann said. "Moreover, every such tear proved to originate from one of the outward pointing edges of the 'can opener' capsulotomy that was the standard in those days." Dr. Neuhann concluded that a continuous contour of the anterior capsulectomy would make this tear- ing difficult to impossible. When looking for ways to create this technique, he was introduced to the "D-shaped capsulotomy," which was created by performing a can opener capsulotomy over the superior 180 degrees, followed by tearing the cap- sule horizontally to join the 3 and 9 o'clock positions of the can opener. Dr. Neuhann said this technique aimed to avoid haptic dislocation. "Since dislocation still occurred in the upper half circumference, I tried to find a way to obtain a tear con- tour over 360 degrees," he said. Still looking for a way to reach his goal late in 1984, Dr. Neuhann came across a particular case of re- tinitis pigmentosa. "My attempts at a can opener capsulotomy were fu- tile, since I could not break the cap- sule without dangerously dislocating the entire lens," he said. "In order to solve this problem, I ended up incis- ing the capsule with the keratome, grasping the incised edge under viscoelastic with a tying forceps, en- larging the tear further, and leading this tear into a circular pattern." This was the first continuous tear capsulorhexis. After discovering this technique, Dr. Neuhann began to work on it as a reproducible technique. However, it was a challenge because viscoelas- tic was not readily available; he had some of the few samples of this where he was working in Germany. "Having heard of Howard Gim- bel's technique presented in 1985, which joined several capsular punc- tures by tears with the capsulotome, I developed a technique to perform a continuous circular tear under irri- gation with a needle-capsulotome starting from a single puncture and including this puncture in the tear- out to create a 360-degree continu- ous tear contour," Dr. Neuhann said. The technique can be performed under all circumstances. It was then that Dr. Neuhann changed the name of the technique to capsulorhexis because it was more of a tear than a cut like a capsulo- tomy. " We first named it continuous circular capsulotomy but because it did not have to be a perfect circle to resist tears, we changed the name to continuous curvilinear capsu- lorhexis," Dr. Gimbel said. What has changed? Dr. Neuhann said there hasn't been much change since he first started using the continuous curvilinear capsulorhexis (CCC) technique. "The unlimited availability of vis- coelastic substances has made the t echnical performance easier and has made technical variations possible, such as the use of forceps through the main incision or tube guided through a paracentesis," he said. Additionally, the advent of capsule dyes has made the visibility with white cataracts easier. He added that with the increased popularity of femtosecond laser-assisted cataract surgery, there has been a return to the can opener technique. "We have better viscoelastic for challenging cases," Dr. Gimbel said. He added that trypan blue can help stain white capsules, which were previously frustrating to deal with. There have been many mechanical devices and means like the Fugo blade (Medisurg, Norristown, Pa.) to cut through a very fibrotic capsule, he said. "Of course now we have the femtosecond laser to make it per- fectly round and centered," Dr. Gimbel said. "But the name of the game is continuous. It doesn't have to be circular. Some argue that it has some effect on lens tilt if it's per- fectly centered and round." He added that the CCC tech- nique has allowed him to develop the divide and conquer technique because with an intact opening, there is no risk of splitting out. The CCC demanded dividing the lens because a very brunescent lens can't be brought out of the capsule unless you have a large opening, Dr. Gimbel said. EW Editors' note: Drs. Neuhann and Gimbel have no financial interests related to this article. Contact information Gimbel: hvgimbel@gimbel.com Neuhann: prof@neuhann.de February 2011 Phaco innovations March 2014 Comparison of a capsulorhexis created freehand and one created with the use of a femtosecond laser. In terms of the continuous curvilinear capsulorhexis (CCC) technique, the femtosecond laser can help make it more round and centered. Source: William J. Fishkind, MD 126-129 2nd Feature_EW March 2014-DL_Layout 1 3/6/14 4:07 PM Page 128

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