Eyeworld

EW NEWS & OPINION 20 August 2016 • Dense cataracts: Dr. Burger said her torsional phaco ultrasound is set at around 60%, and she'll add longitudinal phaco and increase vacuum to better grip nuclear material. Then she'll increase the aspiration flow rate slightly to cool the phaco tip. • Weak zonules: In this case, Dr. Burger said she lowers the bottle height for a lower IOP and uses a lower vacuum and aspiration rate to reduce zonular stress. • Shallow chamber: There are not many changes to her usual phaco parameters in the case of a shallow chamber, but Dr. Burger said she makes sure to not lower the IOP and uses a dispersive viscoelastic to protect the corneal endothe- lium, occasionally reapplying it throughout surgery. A cohesive viscoelastic is applied on top of the iris to maintain anterior cham- ber stability. • Fuchs' dystrophy: While Dr. Burger said she doesn't change her settings for these patients, she will apply Viscoat (Alcon) more frequently. • Intraoperative floppy iris syn- drome: Dr. Burger said she also won't change her settings in this case, but she might use a Malyugin ring for dilation and will apply viscoelastic to the iris margin for stabilization. Find more information about this and other ASCRS webinars at www.ascrs.org/resources/type/ web-seminars. EW Editors' note: Drs. Chang, Chen, and Cohen have no financial interests re- lated to their comments. Dr. Burger has financial interests with Alcon. Dr. Garg has financial interests with Abbott Medical Optics. Contact information Burger: Berdine.Burger@carolinaeyecare.com Chang: dceye@earthlink.net Chen: eschen37@hotmail.com Cohen: klc@med.unc.edu Garg: gargs@uci.edu explained. "As soon as you start in- jecting OVD, go to foot position 0 to allow it to accumulate. Once the AC is filled, you can remove the phaco tip and unplug the incision without shallowing the AC and rupturing the hyaloid face." If an anterior vitrectomy is needed, Dr. Cohen said it is import- ant to be aspirating and cutting while moving the probe around to avoid the risk of tugging on the vitreous and causing a retinal tear or retinal detachment. Dr. Chang addressed how to discuss compli- cations with patients. "After ex- plaining that the case did not go as planned, I make sure to emphasize that the prognosis is still good," he said. "I have the patient and family return to the clinic later that same day so that I can check the IOP and spend as much time as necessary to discuss the prognosis and answer questions." In terms of preventing posterior capsule rupture, Dr. Chang offered the pearl of the viscoelastic vault maneuver to prevent the posterior capsule from trampolining toward the phaco tip as the final nuclear fragments are removed. "The disper- sive OVD resists aspiration, places the posterior capsule on stretch, and blocks the posterior capsule from the phaco tip," he explained. "This is a wonderful safety strategy if you are dealing with ultra-brunescent nuclei in which the epinucleus is absent, or weak zonules where there is an unusually lax and pliant posterior capsule." Further insights When young surgeons are ready to transition from generic resident set- tings to more personalized settings, Sumit "Sam" Garg, MD, medical director, Gavin Herbert Eye Institute, University of California, Irvine— who likes to use the WHITESTAR Signature Phacoemulsification Sys- tem (Abbott Medical Optics) for its ability to switch between peristaltic and venturi pumps—recommended they first receive some information from an industry representative about the phaco machine they're using. "Don't be shy about calling in your phacoemulsification rep to help you personalize your settings as you learn surgery. Also, don't be shy about calling them in on a regular basis to tweak your settings as you gain experience and confidence in surgery," he said, adding that it's important to realize there are no universally accepted settings. "Every eye and every surgery is different." Dr. Burger—who currently uses the Centurion Vision System (Alcon) with a sinusoidal "balance" tip— encouraged young eye surgeons to speak with their colleagues about their machine settings and make use of educational resources, such as lectures and webinars, for help on personalizing settings. "Be willing to play with your settings," Dr. Burger said. "Small, intentional adjustments of a single variable can make a significant dif- ference in efficiency and safety." Drs. Chen, Burger, and Garg all advised those just starting out to go slow. "People rarely regret going too slow, but they often regret going too fast," Dr. Chen said. Slowing down can be achieved by lowering your aspiration settings, Dr. Burger said, adding that lower IOP and bottle height make less of a difference. To speed up, Dr. Burger said increased vacuum can improve one's ability to hold nuclear material and increased aspiration speeds the rate of movement. Here's more advice from Dr. Burger regarding how she would tackle these different conditions from a fluidics standpoint: • Soft lens: It's often possible to aspirate the cataract without any phaco power in this case, she said. Just increasing the vacuum can sometimes be enough to emulsify the cataract without any ultra- sound. allows me to change back and forth between these three vacuum settings during cortical cleanup." Subincisional cortex is addressed first because it holds the capsular bag open, Dr. Cohen said, and al- lows the posterior capsule to remain protected by a layer of cortex should you happen to grab posteriorly. Dr. Chang said his main pearl for sub- incisional cortex removal is proper hydrodissection. "It's the single most underrated step because a good hydrodissection wave loosens the cortex and makes it separate easily in large sheets from the capsular bag," he said. In a more challenging case, such as a deep anterior chamber, Dr. Cohen said you have to worry about reverse pupillary block, and may have to lower the bottle for a more stable anterior chamber, using a small instrument to lift the iris off of the anterior capsule and releasing any trapped fluid. With high myopes, although one can undo pupillary block once it occurs, it is better to prevent it from occurring, Dr. Chang said. "I enter the OVD-filled AC with the phaco tip in foot position 0, and lift the contraincisional iris with the phaco tip prior to engaging foot position 1. Irrigation fluid simulta- neously flows into the anterior and posterior chambers, thereby prevent- ing lens-iris diaphragm retropulsion syndrome from occurring." The faculty then addressed a complication: posterior capsule rupture. Dr. Chang emphasized the need to remain calm. Surgeons should mentally rehearse what needs to be done in this scenario. "Avoid the natural instinct to immediately withdraw the phaco tip and instead stay in foot position 1. The continuing irrigation maintains pressure in the AC and gives you time to think about what you're going to do next," Dr. Chang said. "You're going to take whatev- er OVD is on the table in your left hand to fill and stabilize the AC," he Phaco continued from page 18

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