Eyeworld

continued on next page vitreous hydration (zonules), leaking wounds, and posterior pressure. Jeff Pettey, MD, presented on adjustment of power set- tings. There are only a few variables with power settings, he said: direction of motion (longitudinal, horizontal, combina- tion), magnitude of travel (1–100%), and delivery intervals. Power setting modulation should be explored for non-rou- tine cases. Modern phaco machines' standard settings are excellent for most cataracts. However, atypical cataracts may benefit from setting modulation. For instance, if your machine has an epinucleus setting, Dr. Pettey advised that using that setting when removing your last quadrant can slow down removal during a step when the bag may freely move anteriorly toward your instruments. He turns his phaco off entirely, opting for a "cortex" aspiration and infu- sion-only setting while using the phaco tip. This removes the ultrasound energy during delicate procedures working near the posterior capsule such as removing an epinuclear shell. Finally, he noted how ultrasound energy can work against you when the tip is occluded and it is in viscoelastic, a reci- pe for severe wound burn. "When the tip is in balanced salt solution or aqueous, the fluid can absorb large amounts of heat, cooling the tip, while viscoelastic and an occluded tip can give wound burn in seconds." He added an additional caution for those with a horizontal motion platform because it doesn't clear occlusion as efficiently as longitudinal mo- tion, which plunges the occlusion out. Settings for chopping were discussed by Rohit Om Parkash, MBBS, MS, who said that these are dictated by nuclear density. Soft cataracts are a challenge with the chopping tech- nique. There can be a failed vacuum with occlusion diffi- culty at times, which can result in a cheese-wiring effect where the chopper cuts through the soft material instead of separating it into nuclear halves. From there, it leads to nuclear bowl formation with a tough plate, which is difficult to emulsify due to the risk of capsule rupture. "Because of this, at times with overly soft cataracts, we are not able to chop the nucleus whatsoever," he said. For ultrasoft cataracts in patients younger than 50, the tech- nique involves hydrodissection at multiple locations to re- lease strong cortical adhesions. Once the cataract can rotate fully, Dr. Parkash said to align the tip, place it, impale it, and devour it. The RAPID technique he described was published in the journal Clinical Ophthalmology in 2019. 1 Dr. Parkash said that cataracts appearing soft in patients over 50 may contain relatively large, firm nuclei that cannot be maneu- vered like truly soft cataracts. When the nucleus is difficult to hold, he uses a soft chop with ultrasound, aspiration flow, and vacuum set to zero to avoid penetrating through it. He gently presses the phaco tip into the nucleus, then brings the chopper toward the tip to split the nucleus mechanically. In mild to moderate nuclear sclerosis, Dr. Parkash sets IOP at 36, vacuum at 500, and aspiration at 36. He demon- strated these settings with the oblique chop technique. 2 "Hold it, immobilize it, then chop it," he said. Rock hard cataracts require maximum gripping, Dr. Parkash said, not- ing that his parameters are IOP at 34, vacuum at 650, and aspiration at 42. "For the holding and the immobilization, the sleeve is retracted," he said, explaining that he'll also use longitudinal phaco with no Ozil (Alcon). "After having a good purchase, the pointed chopper is used because it incis- es it; it doesn't let it wobble. … If you find that the nucleus is wobbling, you need to regrip it and complete the chop." Part 1b: Putting the Fluidics and Technology Together – Specific Machine Examples In this section of the symposium, speakers delved into ma- chine-specific details. Dr. Park discussed her experience with the UNITY VCS/ CS (Alcon). "There are two versions of the UNITY: cataract surgery only or combined vitreoretinal and cataract surgery on one machine," Dr. Park said, noting her academic center has a combined machine. Advancements in the Unity include 4D phaco and Intel- ligent Sentry fluidics. What is 4D phaco? Dr. Park showed an animation of the 4D tip, with multidirectional movement. "There is forward and back, torsional, and a dynamic stroke to form a volumetric pattern instead of a simple arc." She explained that this type of movement may reduce the time needed to break up denser lenses. The Intelligent Sentry fluidics can reduce post-occlusion surge and surge volume. The Unity has sensors for both the aspiration pump and the irrigation pump, as well as within the phaco handpiece. Dr. Park added that the handpiece also includes a temperature Dr. Parkash discussed settings for chopping based on nuclear density. Source: Rohit Om Parkash, MBBS, MS

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