EyeWorld Asia-Pacific December 2020 Issue

FEATURE 14 EWAP DECEMBER 2020 W ith modern small incision cataract surgery of 2.7 mm or less, we have to reduce the size of the nucleus so that fragments can be removed through that small incision,” Dr. Yeoh said. “There are many ways of nuclear reduction—Divide and Conquer, Stop and Chop, Direct Chop— all using less energy as we go down the list. FLACS does the same but is expensive. Miloop does the same but you have to learn a new technique. “What about phaco prechop? It reduces energy and is very cheap.” Dr. Yeoh made the case for prechop in his APACRS webinar lecture. Quick and slick The density of the nucleus determines which technique for fragmenting the nucleus is most appropriate. Divide and Conquer, Stop and Chop, Direct Chop, FLACS, and Miloop, he said, are all good for moderate to hard and even very hard cataracts, but do not address the softer end of the spectrum. This, he said, is where prechop comes into play (Figure 1). “Prechop is the division of the nucleus into smaller fragments,” Dr. Yeoh said— into halves, quarters, sixths, eighths—“before ultrasonic phacoemulsification is applied. FLACS is actually a method of prechop but is incomplete; prechop actually separates the nucleus completely.” Prechop was introduced by Takayuki Akahoshi in a video that won an award at the 1994 ASCRS Film Festival, Dr. Yeoh said. Dr. Akahoshi published the technique in Operative Techniques in Cataract and Refractive Surgery 1 and followed this with several more videos extolling the virtues of phaco prechop. “This technique was very quick, very slick, and this was demonstrated at numerous congresses via live surgery, and I well remember one such meeting in which Dr. Akahoshi was demonstrating live surgery and had just started the case when one of my colleagues decided to go to the washroom,” Dr. Yeoh said. “He [the colleague] came back just about 2 minutes later and to his surprise the surgery was already finished, which is just testament to how quick and efficient this technique can be.” There are two main types of prechop: The direct or karate prechop is used for softer nuclei up to 3+ nuclear sclerosis; the counter prechop uses a nucleus Figure 1. Choice of technique for nuclear division by nuclear sclerosis. Source: Ronald Yeoh, MD sustainer for chopping denser nuclei. Dr. Yeoh focused his talk on the direct or karate prechop. He presented two surgery videos in which Dr. Akahoshi uses the prechop to perform cataract surgery in under 2 minutes. Direct or karate prechop, Dr. Yeoh said, is “quick and slick.” It reduces the amount of ultrasound energy used and makes soft cataract surgery “much more elegant”—and it’s cheap, no expensive devices involved. Dr. Yeoh said that many surgeons tried prechop 20 years ago but gave up on the technique. In retrospect, he thinks surgeons did not pay enough attention to nucleus density nor did they take enough care to choose between direct and counter prechop. FLACS: Incomplete division When femtosecond laser-assisted cataract surgery was introduced in 2012, surgeons were impressed by the precise rhexis and nuclear division. However, Dr. Yeoh said, Why are you not prechopping your cataracts? From the lecture by Ronald Yeoh, MD, Singapore Clinical Associate Professor Duke-NUS Graduate Medical School Senior Consultant & Founder Eye & Retina Surgeons Visiting Consultant, Singapore National Eye Centre