Phacoemulsification Surgical Technique

Overview

A phacoemulsification handpiece is driven by a piezoelectric crystal that converts electrical energy into high-frequency ultrasonic vibration at its tip. That vibration fragments and emulsifies the cataractous nucleus so it can be aspirated through a small incision, the mechanism that turned cataract surgery from a large-incision extracapsular extraction into a small-incision, sutureless procedure. Every step below follows a fixed order: enter the eye, open the capsule, free the nucleus from its capsular and cortical attachments, fragment it, remove it, and implant the IOL into the now-empty capsular bag.

Femtosecond laser-assisted cataract surgery (FLACS) automates three of these steps before any phaco probe enters the eye: the corneal incisions, the anterior capsulotomy, and a pre-fragmentation pattern cut into the nucleus. Image guidance gives the laser capsulotomy a tighter, more reproducible diameter than a hand-tied capsulorhexis. Pre-fragmenting a dense nucleus can also cut the ultrasound energy the phaco tip needs afterward by over a third in some series, which matters for corneal endothelial protection. The tradeoff is specific to the capsule: incomplete capsulotomies and capsulotomy tags occur more often with the laser than with manual capsulorhexis, so the surgeon has to find and free any residual bridge before proceeding or risk an uncontrolled tear. Across larger trials, none of this has translated into lower overall complication rates or faster visual recovery than conventional phacoemulsification.

Incision Placement

The main clear corneal incision is usually placed temporally, in clear cornea, well away from the visual axis. Temporal placement sits farther from the visual axis than a superior approach, induces less surgically induced astigmatism, and gives the surgeon easier ergonomic access in most operating room layouts. A second, smaller paracentesis (side-port) incision goes in elsewhere around the limbus for a different purpose: it admits a second instrument, a chopper, a manipulator, or a second cannula, to provide counter-traction and stabilize the eye during maneuvers through the main incision. The phaco probe itself never enters through the paracentesis.

Capsulorhexis Technique & Sizing

Continuous curvilinear capsulorhexis (CCC) is the current standard for opening the anterior lens capsule, and it replaced the older can-opener capsulotomy technique for a mechanical reason. A CCC produces a smooth, continuous circular tear rather than a series of radial punctures. Radial perforations concentrate stress at each puncture point, so a can-opener capsulotomy is prone to an uncontrolled tear that can run out to the equator and, in some cases, into the posterior capsule under the stresses of phacoemulsification and IOL insertion. A smooth curvilinear edge distributes that same stress evenly and resists tearing instead.

A well-constructed capsulorhexis is generally sized to roughly 5 to 5.5 mm in diameter. That range is large enough for adequate surgical access during nucleus removal and IOL insertion, yet small enough that the anterior capsule edge still overlaps the IOL optic circumferentially once the lens sits in the bag. That overlap is what keeps the implant centered and stable long-term.

In mature or white cataracts, poor red reflex can make the capsule hard to see during capsulorhexis creation, which raises the risk of an uncontrolled tear. Trypan blue capsular staining solves this visualization problem directly; see the companion page on OVDs and surgical adjuncts for more on staining technique.

Hydrodissection & Hydrodelineation

Hydrodissection injects fluid beneath the anterior capsule edge, between the capsule and the cortex, breaking the cortical-capsular adhesions that otherwise pin the lens in place. This step has to happen before any nucleofractis maneuver. Without free cortical-capsular separation the nucleus cannot rotate within the bag, and cracking it against unreleased adhesions risks stressing the zonules or the capsule itself.

Hydrodelineation is a related but distinct maneuver. It injects fluid within the substance of the lens itself, producing a visible golden ring that separates the softer outer epinucleus from the harder central endonucleus. Separating these layers lets the surgeon fragment the denser central endonucleus with the ultrasound energy it actually needs, then remove the softer epinuclear shell with markedly less energy, cutting total ultrasound exposure to the eye.

Phaco Ultrasound Technology

The phaco tip's ultrasonic motion can be driven in two fundamentally different patterns. Longitudinal phaco moves the tip back and forth along its own axis, a front-to-back jackhammer motion. Torsional phaco instead oscillates the tip side to side in a rotational motion, and the difference matters clinically. Torsional phaco's shearing, rotational action improves followability (how well a fragment stays held at the tip once engaged) and reduces fragment repulsion compared with longitudinal's pulsatile, repulsion-prone jackhammer action.

Nucleofractis Techniques

Nucleofractis, the fragmentation of the lens nucleus itself, can be approached with several distinct technique families. Each trades off differently between sculpting (removing tissue with ultrasound to create working space) and mechanical force (splitting tissue with instruments instead of ultrasound energy).

Divide-and-Conquer

The surgeon first sculpts a deep central groove using ultrasound energy alone, then uses two instruments to crack the nucleus mechanically, first into halves and then into quadrants. Each quadrant is rotated into position, emulsified, and aspirated individually. This was the foundational nucleofractis technique historically and remains a reliable, teachable approach, though it uses more ultrasound energy than chop-based techniques because a full central groove has to be sculpted before any mechanical cracking begins.

Phaco Chop

Phaco chop skips sculpting almost entirely. The phaco tip embeds into and holds the nucleus under vacuum while a separate chopper is drawn toward the tip, splitting the lens through purely mechanical, opposing shearing forces between the two instruments. Because the initial fracture comes from mechanical splitting rather than ultrasound-driven sculpting, phaco chop delivers meaningfully less total ultrasound energy to the eye than divide-and-conquer.

Stop-and-Chop

Stop-and-chop hybridizes the two techniques above. The surgeon first sculpts a single central groove and cracks the nucleus into two halves, as in divide-and-conquer, then switches to a chopper to divide each half into smaller fragments, as in phaco chop. It combines the more forgiving, familiar setup of an initial groove-and-crack with the lower ultrasound energy of chopping the remaining fragments. Many surgeons use it as a transitional technique on the way from divide-and-conquer to full phaco chop.

Phaco Fluidics

Vacuum (aspiration vacuum) is the fluidics parameter that primarily controls followability: the holding power at the phaco tip once a fragment occludes it. Higher vacuum grips nuclear fragments more firmly and pulls them toward the tip, but at a cost. It also raises the risk of surge, a sudden anterior chamber shallowing or collapse that happens when an occluding fragment suddenly clears and the pressurized fluid column behind it rushes forward unopposed. Balancing vacuum against surge risk is one of the core fluidics judgment calls in phaco, tuned differently depending on nucleus density and which nucleofractis technique is in use.

Small Pupil & IFIS

A poorly dilating or intraoperatively floppy pupil, as in intraoperative floppy iris syndrome (IFIS), can be mechanically expanded with a device such as the Malyugin ring, a flexible iris expansion ring injected through the main incision that engages and stretches the pupillary margin to give safe, stable mydriasis for the rest of the case. Iris hooks are a common alternative to a ring; the companion page on OVDs and surgical adjuncts covers pupil expansion devices in more device-specific depth.

High-Yield Pearls

• Hydrodissection → frees capsule/cortex adhesions; hydrodelineation → separates epinucleus from endonucleus. Both precede nucleofractis.
• CCC's continuous, smooth edge resists radial extension under stress; that's the exact failure mode of the older can-opener technique.
• Target capsulorhexis diameter: ~5–5.5 mm, sized to overlap the IOL optic for centration.
• Torsional phaco = side-to-side; longitudinal phaco = back-and-forth. Torsional improves followability, reduces repulsion.
• Vacuum controls followability but trades off against surge risk when occlusion suddenly breaks.
• Temporal clear corneal main incision minimizes induced astigmatism and visual axis proximity; the paracentesis exists purely for a second instrument.

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