Eyeworld

EW CATARACT 44 September 2018 by Stefanie Petrou Binder, MD, EyeWorld Contributing Writer Special nucleofractis approaches for different types of lens nuclei can improve surgical efficacy and help preserve the integrity of the capsule Breaking down the nucleus Presentation spotlight F resh advice from a sea- soned surgeon can help keep surgeons on their toes. Speaking on nucleus management issues at the 22nd ESCRS Winter Meeting, Rich- ard Packard, MD, Windsor, U.K., offered tactical pearls on how to use a variety of phacoemulsification approaches for nuclei of different densities. "Now that we know how the phaco machine works, we have to understand how to best use it on the nucleus," Dr. Packard said. "In order to be a complete phaco surgeon, a variety of alternate techniques are required to deal with nuclei of dif- fering densities: soft, medium, and hard. When dealing with the nucle- us, mechanical separation minimiz- es energy usage and chopping works best for dens nuclei. White nuclei can be brittle, and multiple separa- tions may be needed to complete a chop. It is important to use power modulation to minimize energy dispersion during phaco. Surgeons should be flexible about varying their technique mid-case and have a range of options for the various types of nuclei." Divide and conquer This four-quadrant nucleofractis technique is the mainstay of phaco surgery for many surgeons. When the surgeon begins to sculpt, it is important to minimize the move- ment of the globe by the correct use of power and by pressing the foot pedal without pushing the nucleus, which can disrupt zonules. With a Kelman tip, the surgeon's hand needs to be held somewhat lower because of its curve, otherwise the tip might get occluded as the bevel is easily buried in the nucleus. Low- ering the hand is easier when oper- ating temporally, but when operat- ing superiorly, the surgeon needs to extend the patient's neck, dropping the head a bit, to gain good access to the eye over the brow. "The important thing with sculpting is to keep the bevel ex- posed to avoid occlusion, which will cause the nucleus to move forward." Dr. Packard said. "We want smooth passes. For trainees, I set the ul- trasound power at 30–70% on the Infiniti and Centurion machines [Alcon, Fort Worth, Texas]. You need to be aware of the diameter of the phaco tip and depth of the nucleus to create the trench at an appropri- ate depth. One of things I encourage to help limit pushing the nucleus is to preset a power range so that as soon as foot position 3 is reached, power is engaged. Also, you want to lift the phaco tip after the center of the nucleus is passed to prevent sculpting through the nucleus to the other side. This is particularly important in softer cataracts with relatively little density." Cracking the nucleus needs the right ergonomics. The long axis of the trench should bisect the sur- geon's instruments, which are posi- tioned at the bottom of the trench. "You are going to go down to the bottom of the trench and separate, but you need to push back though before pushing sideways so it cracks from the bottom, and allow time for the crack to propagate, especially with harder cataracts. To get a good crack in the nucleus, you want an equal and opposite pull on either side," he explained. To remove segments, Dr. Pack- ard buries the phaco tip at minimal ultrasound power and allows the vacuum to build. The sound from the machine lets you know when you've reached maximal vacuum with full occlusion. Then the sur- geon can pull segments centrally, for removal, in the safe area in the deepest part of the anterior cham- ber. This is repeated in each of the quadrants. Chopping "I use multiple chopping ap- proaches, often mixing them as the situation demands," Dr. Packard explained. "Each approach breaks up the nucleus with as little use of power and greatest use of mechani- cal disassembly and fluidics as possi- ble. However, soft cataracts present certain problems. I think the phaco prechop is a good way to approach soft nuclei. You need to fill the an- terior chamber with viscoelastic, do your 5 mm rhexis and full nuclear mobilization, and refill the anterior chamber with viscoelastic to provide a firm base to push the prechop- per against. Push the prechopper toward the center of the nucleus and separate the blades several times until the nucleus splits. Then, turn the nucleus to repeat and remove segments with minimal power. The CENTURION ® VISION SYSTEM IMPORTANT PRODUCT INFORMATION CAUTION: Federal (USA) law restricts this device to sale by, or on the order of, a physician. As part of a properly maintained surgical environment, it is recommended that a backup IOL Injector be made available in the event the AutoSert ® IOL Injector Handpiece does not perform as expected. INDICATION: The Centurion ® Vision System is indicated for emulsification, separation, irrigation, and aspiration of cataracts, residual cortical material and lens epithelial cells, vitreous aspiration and cutting associated with anterior vitrectomy, bipolar coagulation, and intraocular lens injection. The AutoSert ® IOL Injector Handpiece is intended to deliver qualified AcrySof ® intraocular lenses into the eye following cataract removal. The AutoSert ® IOL Injector Handpiece achieves the functionality of injection of intraocular lenses. The AutoSert ® IOL Injector Handpiece is indicated for use with the AcrySof ® lenses SN6OWF, SN6AD1, SN6AT3 through SN6AT9, as well as approved AcrySof ® lenses that are specifically indicated for use with this inserter, as indicated in the approved labeling of those lenses. WARNINGS: Appropriate use of Centurion ® Vision System parameters and accessories is important for successful procedures. Use of low vacuum limits, low flow rates, low bottle heights, high power settings, extended power usage, power usage during occlusion conditions (beeping tones), failure to sufficiently aspirate viscoelastic prior to using power, excessively tight incisions, and combinations of the above actions may result in significant temperature increases at incision site and inside the eye, and lead to severe thermal eye tissue damage. Good clinical practice dictates the testing for adequate irrigation and aspiration flow prior to entering the eye. Ensure that tubings are not occluded or pinched during any phase of operation. The consumables used in conjunction with ALCON ® instrument products constitute a complete surgical system. Use of consumables and handpieces other than those manufactured by Alcon may affect system performance and create potential hazards. AES/COMPLICATIONS: Inadvertent actuation of Prime or Tune while a handpiece is in the eye can create a hazardous condition that may result in patient injury. During any ultrasonic procedure, metal particles may result from inadvertent touching of the ultrasonic tip with a second instrument. Another potential source of metal particles resulting from any ultrasonic handpiece may be the result of ultrasonic energy causing micro abrasion of the ultrasonic tip. ATTENTION: Refer to the Directions for Use and Operator's Manual for a complete listing of indications, warnings, cautions and notes. © 2018 Novartis 8/17 US-CNT-18-E-1839 103205US-CNT-18-E-1839_PI EW.indd 1 8/27/18 1:40 PM

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