Time for your favorite CataractQuiz™ episode: look carefully (very carefully) at this title picture and tell me what is the problem here. The case is not over until we resolve this issue. It is not the air bubble on the cornea. The IOL is in the bag. The capsulorhexis is great. There is no zonulopathy. So what is the issue? Stop reading here if you want to watch the video yourself to figure it out!
stop scrolling because the answer is going to be revealed below…
Retained lens fragments are a frustrating complication that can challenge even the most meticulous cataract surgeon. While modern phacoemulsification has made the procedure remarkably efficient, the high-energy ultrasonic fragmentation of the nucleus inherently creates nuclear chips. These small pieces of nuclear material that can migrate into the deep recesses of the anterior segment. If left behind, these fragments can lead to chronic inflammation, localized corneal edema which is classically at the inferior limbus, and sometimes secondary glaucoma. To minimize this risk, a surgeon must transition from simply completing the case to actively searching for debris through specific intra-operative maneuvers.
The search for fragments begins during the final stages of nuclear removal. As the last quadrant is emulsified, the relatively empty capsular bag creates more open volume which allows fluid currents to become more turbulent, often pushing small slivers into the periphery. A useful maneuver to prevent this is to shake or vibrate the eye slightly with the phaco tip or a second instrument before withdrawing. This mechanical agitation can dislodge fragments that are adherent to the iris or trapped in the capsular equator.
Surgeons can also adopt the habit of accounting for the entire lens volume; if the quantity of material removed seems insufficient for the cataract’s density, a fragment is likely hiding in a blind area. In cases where the pupil dilation is only modest, there is a higher risk of a small nuclear piece becoming lodged behind the iris. Using the chopper or second instrument to temporarily tent up the iris in all quadrants can be helpful.
The sub-incisional space remains the most notorious hiding place because it is situated directly beneath the surgeon’s primary field of view and is often shielded from the main fluidic current. To clear this area, the surgeon can gently depress the peripheral iris with the irrigation / aspiration probe or a cannula, which may reveal previously invisible material.
Lighting also plays a critical role. By varying the microscope’s illumination or shifting to an oblique light source, the surgeon can often catch the glint of a translucent nuclear chip that would otherwise be lost in the red reflex. In particular patients with light colored iris stroma may be at higher risk since there is less contrast to visualize these nuclear fragments on top of the iris. (Figure 1)
Additionally, since viscoelastic devices (OVDs) are designed to be sticky, they can trap fragments against the angle or the posterior surface of the iris. Complete OVD removal, including from the space behind the intraocular lens, is therefore a prerequisite for a truly clean eye. The most definitive maneuver for ensuring a debris-free anterior segment is the angle sweep technique. This involves using a 27-gauge blunt cannula on a syringe of balanced salt solution (BSS) at the very conclusion of the surgery, after the intraocular lens has been centered and the incisions hydrated. (Figure 2)
Because gravity and fluidics naturally drive debris toward the inferior 180 degrees of the eye, the surgeon inserts the cannula through the paracentesis and directs a vigorous stream of BSS toward the opposite angle. By sweeping the cannula across the angle, the surgeon creates a localized power wash that dislodges trapped OVD and any sequestered nuclear fragments. This retained OVD would have also caused an increase in the intra-ocular pressure in the post-op period as it would clog the trabecular meshwork. (Figure 3)
It is common for a seemingly pristine eye to suddenly yield a hidden chip once this turbulence is introduced. If a fragment is discovered postoperatively, the surgeon must distinguish between soft cortex, which may resorb with steroids, and hard nucleus, tends not to. Persistent inflammation or a focal area of swelling at the inferior limbus is a hallmark of a retained nuclear piece. While small fragments under two millimeters can sometimes be managed medically, larger or denser pieces usually necessitate a return to the operating room for a formal anterior chamber washout.
By integrating these exploratory maneuvers like the eye shake, sub-incisional inspection, and the BSS angle sweep, surgeons can drastically reduce the incidence of retained lens fragments and rebound inflammation to ensure the highest standard of surgical success.
