Dodick prechoppers: The best kept secret in cataract surgery

There is little to no stress placed on the capsular bag or the zonules, and there is no risk of putting too much posterior pressure on the nucleus and capsule.

Did you ever wonder why everyone does not drive the car you drive? Does it seem strange to you that your favorite restaurant is not crowded to the hilt? Ever ask yourself why everyone does not sit in the exit row on the airplane to gain increased foot room? The answer to all of these is probably about the same — different strokes for different folks.

There is one “different stroke” that to my amazement has never been touted at any cataract meeting I have attended, except by one man, who happens to be its creator. Even he does not tout it for routine cataract surgery but has discussed it predominately in conjunction with his “laser phaco” technique.

Not appealing at first

In 2002, I had the pleasure of visiting with Jack M. Dodick, MD, in his operating room in Manhattan. He was a gracious host and allowed me to watch him perform his technique with the idea of purchasing his laser phaco equipment and converting to that technique where appropriate.

I found that the laser technique was not useful in dense cataract, and even in those that were soft, it required a “crack and cram” technique, whereby Dr. Dodick would force the nuclear segments into the laser handpiece opening, not unlike when you have a small piece of nucleus left in the anterior chamber and you have switched to using your irrigation and aspiration tip. You have to chop up the fragment with your cracker or chopper and the port of the irrigation and aspiration tip.

We all do it routinely, but to make that a predominant part of my cataract technique simply did not appeal to me. However, I noted that there were a significant number of cases in which Dr. Dodick decided to convert to phacoemulsification because of the density of the nucleus, either initially or during the process of the case. In most of these, he still did his prechop technique that transected the nucleus into quadrants, making the removal of the nucleus extremely simple in the majority of cases using the phaco, also a part of his machine.

Making the transition

As I observed, I began to wonder how Dr. Dodick’s technique would work on small pupils and asked if he felt it was a good approach there as well. “It’s even better for small pupils because you have the lens deconstructed before you even begin your phacoemulsification and don’t have to deal with the pupil, other than secondarily,” he said.

I also asked about how often he had bagged the capsule using the prechoppers, and to my surprise, he said he had not seen that to date.

When I returned home, I was interested in attempting this prechopping technique. I was a bit reluctant to place the choppers under the capsule and to have two instruments in the eye at the same time, both of which could be considered hooks. However, I realized that if I was to see the benefits of the technique, I would have to make some transition to its use. To my surprise, the chopping of the nucleus into quadrants came fairly easily, and much to my pleasure, we found our phaco times were down by about 50%.

Figure 1. With the blade parallel to the capsule, the left prechopper is inserted through the side port and slid under the cortex and capsule, then rotated so the blade is perpendicular and sitting at the equator of the nucleus. Slight movement circumferentially allows visualization of the nucleus rotating in the capsule and ensures your placement of being in the capsule.

Figure 2. The second prechopper is inserted through the cataract incision, again parallel to the capsule and slid under the capsule about 180° from the placement of the first chopper, then rotated perpendicular. Images: Brister L

Figure 3. With both prechoppers in place, you pull toward the center, watching the progress of each and adjusting the angle if necessary. As they meet, the nucleus will split into two hemispheres.

Figure 4. Keeping the left hand centrally, the right hand is used to rotate the nucleus counter-clockwise; the prechopper is slid under the capsule again and after rotation pulled again to center, creating two quadrants.

Figure 5. Again, the right hand is used to rotate nucleus, this time clockwise to bring the second hemisphere to your right hand, where the second hemisphere is chopped into quadrants.

Figure 6. This shows the nucleus transected into four quadrants, all of varying size and shape but now easily removed and emulsified with the phaco tip.

Figure 7. This shows one quadrant on the phaco tip and the space it maintained before being lifted as a red reflex.

Predictability and speed

Over the past 7 years, I have performed thousands of cases utilizing this prechop technique and have found it to speed up my surgery, as well as make what would otherwise be difficult cases into much more predictable ones. Specifically, I find it is helpful for the following:

Small pupils: This takes a great deal of the difficulty out of these cases. As long as you can get the nucleus deconstructed before the pupil begins to come down, you have half the battle won. Before converting to the prechopping technique, such cases were extremely difficult for me, as I was attempting to work blind. Of course, there are many things that have helped us in dealing with this condition, but for me, prechopping has been by far the biggest improvement to my armamentarium.

Pseudoexfoliation syndrome and poor to loose zonules: The advantage prechopping adds here is similar to that in small pupils. Breaking down the lens without any stress on the capsule makes removing the fragments much easier and less risky. Obviously, the addition of an intracapsular ring may add some stability here, but getting to that point is made easier by the early fragmentation of the nucleus.

Intraoperative floppy iris syndrome: This is basically the same as with any small pupil but worse. Even a small portion of the nucleus being broken off by the prechop technique facilitates removal of the other portions. That is particularly advantageous in cases in which the pupil retracting can make visualization difficult and risky. It is such an advantage that I would not even want to attempt these cases now without this technique.

Hypermature cataracts: The deconstruction of these hard nuclei is not easy with any technique but is much easier by this technique than any I have used in the past. There are those cases that are so dense that I cannot pull the prechoppers through them. If that is the case, I recommend slicing off a section on the edge, or more than one piece if possible. It is the same concept that I discussed above in intraoperative floppy iris syndrome. That will at least allow easy movement of the nucleus and easier chopping of the nucleus in the more usual fashion. Most hypermatures, however, will prechop nicely, and removal is simple.

In summary, if you have considered various forms of chopping techniques but found them to be difficult to master, I would recommend that you consider the simple technique of prechopping, utilizing the Dodick prechoppers. Compared with other forms of prechopping, there is little to no stress placed on either the capsular bag or the zonules during the process of chopping, and there is no risk of putting too much posterior pressure on the nucleus and capsule, thereby posteriorly dislocating it as with the one-hand prechoppers available.

Here is a summary of my technique:

• A side port is placed at 2 o’clock for use throughout the procedure.
• The 3-mm incision is placed at about 135°.
• A routine capsulotomy is performed.
• Hydrodissection and hydrodelineation are both performed, looking for rotation of the nucleus freely in the capsular bag as the intended endpoint.
• Further viscoelastic is placed centrally, pushing the debris peripherally and allowing better visualization of the capsule edge and the intended plane placement of the choppers.
• With the blade parallel to the capsule, the left prechopper is inserted through the side port and slid under the cortex and capsule, then rotated so the blade is perpendicular and sitting at the equator of the nucleus. Slight movement circumferentially allows visualization of the nucleus rotating in the capsule and ensures your placement of being in the capsule.
• The second prechopper is inserted through the cataract incision, again parallel to the capsule and slid under the capsule about 180° from the placement of the first chopper, then rotated perpendicular.
• With both prechoppers in place, you pull toward the center, watching the progress of each and adjusting the angle if necessary. As they meet, the nucleus will split into two hemispheres.
• Keeping the left hand centrally, the right hand is used to rotate the nucleus counterclockwise. The prechopper is slid under the capsule again, and after rotation pulled again to center, creating two quadrants.
• Again, the right hand is used to rotate the nucleus, this time clockwise to bring the second hemisphere to your right hand, where the second hemisphere is chopped into quadrants.
• The choppers are removed from the eye.
• The phacoemulsification of the quadrants is performed at or near the iris plane, and the cortex removed and the capsule polished.
• The lens is placed, and the incisions are sealed.

• Lin Brister, MD, can be reached at Eye Care for Tulsa, 1145 South Utica, Suite 162, Tulsa, OK 74104; 918-585-1523; e-mail: linbrister@hotmail.com.