EyeWorld Asia-Pacific June 2014 Issue

38 EWAP CAtArACt/IOL Pseudophakic dysphotopsia June 2014 Innovations in capsulorhexis by Ellen Stodola EyeWorld Staff Writer 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 director and the founder of the Laser Eye Center Munich, Germany, and Howard Gimbel, MD , Gimbel Eye Centre, Calgary, Alberta, Canada, are two surgeons widely credited with creating the technique of the capsulorhexis. They discussed the continuous curvilinear capsulorhexis (CCC) and how it has changed since its creation more than 20 years ago. Inventing the technique Dr. Gimbel explained that the invention of this technique relates largely to the evolution of the capsule 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, always 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 surgeons placed the IOL in the ciliary sulcus, while others preferred placement 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 frequent 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 “unacceptably high occurrence” of asymmetric 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 tearing 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 capsule 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 contour 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 retinitis pigmentosa. “My attempts at a can opener capsulotomy were futile, since I could not break the capsule without dangerously 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 rounded and centered. Source: William J. Fishkind, MD