Phaco fracture “divide and conquer” technique
The most widely used 2-handed technique, referred to as “divide and conquer nucleofractis,” can be effectively applied to all but very soft cataracts.
After adequate hydrodissection (and hydrodelineation if desired), continuous ultrasound is used to sculpt a deep central linear groove or trough in the nucleus that is 1 to 1½ times the width of the phaco tip. Signs of adequate groove depth include smoothing of the striations in the groove, brightening of the red reflex in the groove, and sculpting to a central depth of 2 or 3 phaco tip diameters (Fig 8-10).
At this point, the surgeon can either separate the nucleus into 2 pieces (nucleus cracking) or rotate the nucleus 90° and sculpt a perpendicular groove (Video 8-3). The phaco tip and second instrument are then inserted into each groove and spread apart, thereby achieving complete separation/cracking of the pieces (Fig 8-11).
VIDEO 8-3 Nucleus cracking.
Courtesy of Lisa Park, MD.
The surgeon can then engage a quadrant using the phaco tip and a segment removal setting. After adequate vacuum has been attained, the nuclear quadrant is pulled toward the center of the capsular bag and emulsified. Each quadrant is sequentially removed in the same manner.
Chopping techniques
The horizontal phaco chop technique does not entail creation of a central groove but instead uses the natural fault lines in the lens nucleus to create a fracture plane. After burying the phaco tip in the center of the nucleus while using high vacuum, the surgeon inserts a chopping instrument under the anterior capsule flap (Fig 8-12), deeply engages the endonucleus in the periphery, and draws it toward the phaco tip, thereby cracking the nucleus into 2 pieces (Video 8-4). This technique requires the surgeon to place the chopper under the capsular rim and around the equatorial nucleus. The phaco tip is then buried in 1 of the nuclear halves, and the surgeon uses the chopping instrument in the same fashion to create multiple small wedges of nucleus for emulsification.
VIDEO 8-4 Horizontal phaco chop technique.
Courtesy of Lisa Park, MD.
A modification of this procedure entails sculpting a central groove and then cracking the nucleus into 2 pieces. The resulting heminuclei are then chopped into smaller pieces. This technique, known as stop and chop, affords the surgeon more room to manipulate the nuclear pieces in the capsular bag.
Vertical chopping techniques have also been described. After the center of the nucleus is impaled with the phaco tip using high vacuum, the surgeon buries a chopper with a sharp tip within the nucleus, just adjacent to the phaco tip (Fig 8-13). The phaco tip lifts while the chopper depresses, and the surgeon separates the instruments to complete the chop, which occurs along natural fault lines in the nucleus (Video 8-5).
VIDEO 8-5 Vertical phaco chop technique.
Courtesy of Lisa Park, MD.
In practice, either the vertical or the horizontal chopping technique can be used with almost any other strategy for disassembly of the nucleus. Chopping may be difficult in soft nuclei, for example, as with pure posterior subcapsular cataracts. Other techniques, such as hydrodelineation and aspiration with minimal phaco power, may be more appropriate in these cases.
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Chang DF. Phaco Chop and Advanced Phaco Techniques: Strategies for Complicated Cataracts. 2nd ed. Slack; 2013.
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Steinert RF, ed. Cataract Surgery. 3rd ed. Saunders; 2010.
Excerpted from BCSC 2020-2021 series: Section 11 - Lens and Cataract. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.