Phaco Chop With Ozil

I really like to use the Alcon Infinity Ozil system for phaco chop.  i think there are 3 distinct phases to phaco chop with the ozil and they are outlined below:

Chop Phase. In this phase we are chopping the nucleus into 6 pieces.  I like to start using longitudinal ultrasound (no Ozil) as i think the side to side motion of the Ozil does not allow one to occlude as tightly as when you use longitudinal ultrasound.  I recommend a high fixed aspiration flow rate (AFR) and high fixed vacuum cut off.   By fixed i mean that no matter where i am in position 2 or 3 of the foot pedal the vacuum and AFR are the same.   I usually have the AFR at about 30-35 and the vacuum cut off at about 300-350. This will require a fairly high bottle height 90-110 to keep surge to minimum depending on how much fluid you are losing around the wound.  You will need to adjust the longitudinal ultrasound power depending on the density of the nucleus (40-80%).   I like to use either a burst setting or a 4 Hz frequency pulse (Dr Howard Fine coined the term choo choo chop as it sounds like a train).   I like to use a horizontal chop for the intial crack and then a sort of hybrid horizontal and vertical to break the halves in 6 pieces.   I like the Siebel Chopper as shown in the video below

When doing the initial phaco chop (assuming you are right handed) you want the left side of the completely embeded phaco needle to be in the center of the lens.    Then imagine a line drawn from the left side of the phaco needle out to the periphery of the lens under the cpasule.  this is the line of the chopper as it slices through the lens.   As you chop toward the needle (horizontal chop) and get just to the left side of the phaco needle lift up a bit on the needle and push down a bit on the chopper (vertical chop) as you simultaneously also push the instruments away from each other.  (best learned from video below).  After the nucleus is divided in half with the initial chop rotate the lens clockwise about 60 degrees to begin to break each half into thirds.  The chopping is similar for the halves except i usually dont go out so peripheral and accentuate the vertical part of the motion over the horizonal.  I usually try to break each half into thirds or 6 pieces total.  

Segment removal phase. After the lens is chopped into 6 pieces I switch to the Ozil mode.   Similar to the chopping settings, I like a high fixed AFR and fixed vacuum for this mode.   I usually have the AFR at about 30-35 and the vacuum cut off at about 300-350 with a continuous Ozil at 70-100%.  The side to side motion of the Ozil creates less repulsive force than the longitudinal ultrasound and the material really flows into the tip and out of the eye.   If you encounter a very hard nucleus you may need to add in some longitudinal phaco power to keep the tip from occluding as it sometimes does with only Ozil.

Shizzel phase.   After the nucleus is removed you often have some epinuclear material left over.  I like to switch to a low setting of Ozil (<40%) with linear control of the AFR (max at 30-35) and vacuum (max at 300-350).   By linear I mean that the harder I push the pedal into position 2 the more AFR and higher vacuum cut off I get.   This mode gives you very fine control (venturi like) when grabbing the delicate epinuclear material helping to prevent you from swiss cheesing through it to the bag.  Shizzle is a term coined by Drs Graff and Friedrichs of Iowa that refers to holding the epinuclear material high with the phaco while sweeping under to push out the subincisional material (the Shizzel is best appreciated on video).

Here is the video of Ozil phaco chop.

Learning phaco chop is best done in steps or stages.   Start by simply getting used to having the chopper in the eye while doing divide and conquer.  Then transition to chopping parts of the lens like a quarter or a half as in stop in chop.  The white cataracts are great for your first chop cases as they are brittle and easily chop and as the delicate capsule is easy to see with the Trypan stain. 

Here is a video outling some of the steps to learning phaco chop