美食街之白內障手術大成功~
白內障手術植入多焦點人工水晶體也可以順帶一起矯正老花眼
----客製化微創小切口白內障追蹤定位手術，精準 計算及植入矯正老花的人工水晶體---Customized Phacoemulsification with VERION™ Image Guided System and AutoSert IOL Injector---Micro-incision Cataract surgery
張女士平時在百貨公司美食街擔任清潔人員，這半年來，因為常常看不清楚，工作起來很吃力，甚至收碗盤時及清潔桌椅時都看不清楚，常覺得桌子怎麼老是擦不乾淨，工作起來大不如以前的俐落。於是到我們眼科求診，被診斷是白內障問題，病人也想藉著這次白內障手術植入高階人工水晶體，一併解決遠視、老花眼的問題，對術後的效果心中充滿期待。
藉由威力揚定位系統(VERION Image Guided System)在手術中可精準植入高階多焦點人工水晶體，期待能達到最正確的手術矯正治療。植入高階多焦點的人工水晶體，如果沒有對準到視軸中心(Visual axis)，將會使多焦點人工水晶體的效果大打折扣，相當可惜。
張女士在術後第1週回診，經檢查結果左眼視力看遠、看近皆可達1.0 (20/20)，張女士覺得視力看遠看近都變好，現在工作上更得心應手，也更有自信，既使已經62歲，現在的視力甚至比一些年輕的同事看得更清楚，她非常滿意這次的老花眼、白內障手術效果，很感謝新眼光醫療團隊的細心照顧與治療。
(白內障手術前,水晶體呈琥珀白色混濁)
(白內障手術後,清晰可見高階人工水晶體的多焦點繞射環)
參考資料：
Horizontal phaco chop makes cataract surgery more efficient with less ultrasonic energy
Learning phaco chop is a straightforward transition for experienced surgeons who use the divide-and-conquer technique.
Uday Devgan, MD
More than 20 years ago, Dr. Kunihiro Nagahara described the technique of phaco chop, which transformed cataract surgery by making it more efficient. His idea was simple: Use mechanical energy to break the cataract nucleus into smaller pieces instead of using the standard divide-and-conquer technique. Phaco chop requires less ultrasonic energy to disassemble the nucleus, and that means less damage to the delicate corneal endothelial cells, which makes for less inflammation and a faster postoperative recovery.
About phaco chop
Although the technique seems difficult, it is actually surprisingly simple to learn. Despite this reasonable learning curve, many cataract surgeons have not adopted this technique. During the course of the past 15 years, I have taught phaco chop to resident surgeons as part of their surgical training. Surgeons who currently use the divide-and-conquer technique are already adept at having a second instrument in the eye for the cracking portion of the nucleofractis technique. Learning phaco chop is a straightforward transition for these experienced surgeons.
The classic Nagahara technique is a horizontal chop, which means that the principal plane of movement is horizontal, parallel to the iris and lens surface. This is different from a vertical chop technique, whereby the goal is to propagate a crack vertically, toward the posterior capsule. For this article we will focus on the horizontal chop, which is suited to a wide range of nuclear densities and works well with most chopping instruments.
The only additional instrument that is needed is the chopper. This instrument has a tip that is just a few millimeters long in order to avoid touching the posterior lens capsule when the chopper is placed at the nucleus equator. The phaco platform settings must be adjusted so that the phaco probe is able to securely hold the cataract nucleus as the chopper divides it. This means that the vacuum level should be increased to 300 mm Hg to 500 mm Hg, depending on the size of the phaco tip, with a larger tip requiring less vacuum pressure than a smaller one. The flow rate and the bottle height/infusion pressure should be balanced and at a moderate range in order to facilitate nuclear fragment removal. Ultrasonic phaco power depends on the density of the nucleus, with a denser nucleus requiring more power.
The technique
Once the capsulorrhexis is created and hydrodissection is performed to mobilize the nucleus, the first move, which is also the most critical, is the proper placement of the chopper. This instrument needs to be placed around the lens equator, under the capsulorrhexis edge, and this view may be obscured by the iris if it is not maximally dilated. For beginners, I suggest sliding the chopper along the anterior surface of the lens and then pushing the capsulorrhexis edge until the chopper tip reaches the lens equator. At this point, the chopper will slightly drop as it reaches the lens equator and the capsulorrhexis will snap back into position. This is the correct placement of the chopping instrument, and it can be placed before impaling the nucleus with the phaco probe.
More experienced surgeons will simply tilt the chopper tip on its side and then pass it toward the lens equator, and once there, they will straighten the chopper so that it is in position. In order to chop the nucleus, we must fixate and stabilize it. This is done by burying the phaco tip into the nucleus and using the high vacuum level to hold it still. Now the chopping maneuver takes place by bringing the chopper toward the phaco probe to start a fracture in the lens nucleus. Then, the force vector shifts by about 90°, and the chopper is used to pull the two nuclear pieces apart. The fracture propagates through the entire nucleus, and two clean halves are created. At this point, the nucleus halves can be further chopper into quadrants or sextants.
As surgeons become more adept at this maneuver, a few subtle improvements can be incorporated. These include placing the chopper at the same time as the phaco probe impales the nucleus; chopping during the initial application of power as the phaco tip is being buried in the nucleus; using the phaco probe to push one nuclear half away from the other to facilitate the propagation of the nuclear split; and angling the phaco probe during sub-chops so that nucleus rotation can be minimized.
While we now have femtosecond lasers that can also divide the cataract nucleus into fractions, the horizontal phaco chop technique can achieve the same results more efficiently with less time and with a small degree of mechanical energy. This is a technique that has stood the test of time and has made cataract surgery more efficient and more enjoyable for the surgeon as well as the patient who gets the benefit of a minimally invasive technique and excellent visual results.
