Disc blade prechopper
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First Author: T.Akahoshi JAPAN
The conventional phaco prechoppers with sharp blades are suitable for prechopping medium to dense nuclei to facilitate the following phacoemulsification. However soft cataract was not easy to prechop by such prechoppers as the narrow blades couldn’t provide proper separation vector to the nucleus. Further more the surgeons had psychological hesitate to insert a sharp instrument into the nucleus for fear of rupturing the posterior capsule. The purpose of this study is to develop a prechopper which is safe and suitable for prechopping soft cataract.
Three different prototype prechoppers were tested in more than 2,000 cases of cataract surgery at Nihonbashi Cataract Clinic and Akihabara Eye Clinic in Japan.
Sharp angular edges were completely eliminated from the blade. The blade was made mirror polished disc shape with the thinnest thickness. One semicircular edge was sharp while the other half was round and blunt. As the first step, the sharp side of the blade is used to insert into the nucleus with minimum resistance and least stress on the ciliary zonules. After bisecting the nucleus, the blunt side of the blade can be used safely to complete the separation of the nuclear posterior plate. The dent on the handle indicated the blade edge characters, sharp or blunt.
Grade I to III (LOCS III) could be easily prechopped by the vertical Karate Prechop technique. As the blade is extremely thin and mirror polished, insertion into the nucleus was smooth. As the blade had sufficient surface area, separation of the soft nucleus was quite easy. As the semicircular edge of the blunt side was rounded, complete separation of the posterior plate could be attained safely close to the posterior capsule. The prechopped nucleus could be phacoemulsified quite efficiently at CDE 3.33±1.39, Aspiration Time 32.2±8.3 sec and BSS 19.2±5.3ml.
This new prechopper is suitable for prechopping soft cataract which was difficult to manage with the conventional prechoppers. As the prechopper blade is cymbal like round disc shape without any angular edge, the psychological stress to insert into the nucleus can be eliminated. Complete separation of the nucleus can be performed very close to the posterior capsule thanks to the blunt semicircular edge of the blade. Once the nucleus is prechopped into smaller pieces, the following phacoemulsification is safe and quick. This new prechopper will benefit the safety and efficiency of cataract surgery in soft nucleus.