Phaco Quick-Chop

Since the introduction of traditional phaco chop by Kunihiro Nagahara, MD, of Japan, many variations have been described. In my experience, the safest and most efficient refinement is the phaco quick-chop technique, a term coined by David Dillman, MD, of Danville, IL. This variation has been described contemporaneously by several investigators, including Tobias Neuhann, MD, of Germany, Abhay Vasavada, MD, of India, and Vladimir Pfiefer, MD, of Slovenia. The snap-and-split variation developed by Hideharu Fukasaku, MD, of Japan is also quite similar. The modification that these techniques have in common involves the location and placement of the manual chop instrument; rather than making an excursion out to and around the equator of the lens, the manipulator is pressed down onto the anterior surface of the nucleus just in front of, or to the side of, the impaled phaco tip.

The phaco quick-chop technique is becoming increasingly popular among surgeons who find traditional phaco chop to be awkward and potentially dangerous, because placing the chop instrument out to the periphery and under the anterior capsule can be difficult or impossible to visualize. The subtle refinement of quick-chop allows the surgeon to efficiently divide soft, medium, and very hard lenses. Furthermore, it works well with small pupils, as well as in eyes in which a generous capsulorhexis cannot be obtained.

PERFORMING PHACO QUICK-CHOP
To perform this procedure, the surgeon deeply impales the central nucleus using short bursts of pulsed phaco energy along with a steep angle of attack into the central lens substance (Figure 1A). It helps to retract the silicone sleeve, exposing more of the metal needle, in order to maximize a deep purchase. The surgeon then places the chop instrument just in front of (or to the side of) the buried phaco needle. Using the side-port incision as a fulcrum, the surgeon then presses the distal tip of the chop instrument assertively downward into the nucleus as the phaco tip provides countertraction and a small degree of upward movement. As the physician creates the cleavage plane, he or she laterally spreads apart the chop instrument and phaco tip, propagating the division entirely across the nucleus from one pole to the other, as well as down and through the posterior nuclear plate (Figure 1B). It is extremely important to verify that each successive cleavage plane is completely through the lens. One should not progress to the next chop unless this has been carefully verified.

The surgeon then rotates the reimpaled lens, and repeats the vertical down chop maneuver (Figure 1C). As the lens density increases, the surgeon should create a greater number of cleavage planes (Figure 1D). Once a section is chopped, he or she uses the manipulator to push the chopped segment out toward the fornix of the capsular bag, causing the posterior apical portion of the chopped segment to present upward for easier purchase with the phaco tip. The surgeon should use high levels of vacuum and flow rate to evacuate these segments, aided by short bursts of pulsed phaco energy to collapse the nuclear material into the phaco tip. He or she may facilitate the purchase of chopped segments by rotating the phaco instrument around its long axis to allow parallel alignment of the needle's bevel with the surface or facet of the nuclear segment, thereby improving occlusion (Figure 1E).

POINTS TO NOTE
As with any endocapsular technique, the phaco quick-chop technique requires complete and effective hydrodissection, or alternatively, hydrodelineation. I personally utilize this hydrodelineation maneuver in order to create a concentric division plane between the hard inner endonucleus and the soft outer epinucleus. Working within the confines of the epinucleus potentially increases the safety of the procedure. In addition, chopping an endonucleus allows the surgeon to create smaller segments of nucleus, subsequently making purchase and removal easier. The surgeon performs evacuation of the epinucleus by gradually debulking and trimming the epinuclear rim until it spontaneously collapses upon itself. It can then be aspirated using little, if any, phacoemulsification energy.

Choosing the correct chop instrument is also important. With the traditional Nagahara phaco chop method, many surgeons prefer using a chopper that incorporates a blunt or bulbous distal tip to increase safety when passing the instrument peripherally. With the phaco quick-chop technique, a more pointed, beveled, or flattened tip will more easily impregnate itself into the lens material. I currently prefer the Nichamin Quick Chopper II (Rhein Medical, Inc., Tampa, FL, model #8-14533). I am also fond of the Nichamin Nucleus Divider (Storz Medical AG, Schweiz, Germany, model #E0726).

PROVEN SAFETY AND EFFICIENCY
In summary, the phaco quick-chop technique is now my preferred approach for phacoemulsifying almost all types of lenses. I believe that this technique is inherently the safest and most efficient approach to nuclear disassembly, and has proven to be a very easy technique to teach to other surgeons.

Louis D. Nichamin, MD, is Medical Director of the Laurel Eye Clinic in Brookville, Pennsylvania. He does not hold proprietary interest in any product or technology mentioned herein. Dr. Nichamin may be reached at (814) 849-8344; nichamin@laureleye.com