Cataract surgery on an intumescent white cataract presents unique challenges that require careful planning and precise intraoperative technique to avoid complications such as capsular rupture or zonular stress.
These mature cataracts, often referred to as "white" or "hypermature" due to their milky appearance, are swollen with liquefied cortex under pressure. The anterior capsule is often under significant tension, and visualization is poor due to the absence of a red reflex. The key to successful surgery lies in mastering techniques that safely decompress the lens, achieve a well-controlled capsulorrhexis and preserve the integrity of the capsule throughout phacoemulsification.
One of the most critical steps in managing an intumescent cataract is the creation of a controlled and continuous curvilinear capsulorrhexis (CCC). Unlike typical cataracts, the increased intralenticular pressure in white cataracts poses a high risk for the "Argentinian flag sign" -- a radial tear of the anterior capsule caused by the uncontrolled extension of the capsulorrhexis once punctured. To mitigate this risk, surgeons often employ a multi-step decompression technique. After a small paracentesis and injection of a cohesive ophthalmic viscosurgical device (OVD) to flatten and stabilize the anterior chamber, the anterior capsule is initially stained with trypan blue dye under an air bubble to improve visualization. Once the dye is rinsed, a second injection of OVD can further stabilize the chamber and flatten the lens surface.
Decompression of the lens is then performed either by using a 30-gauge needle on a syringe to puncture the anterior capsule and aspirate the milky liquefied cortex or by creating a small capsular nick with a cystotome and aspirating the fluid with a cannula. This step relieves intralenticular pressure and reduces the risk for uncontrolled capsule tearing. In some cases, a two-stage capsulorrhexis is preferred: The surgeon first creates a small central opening, decompresses the lens, and then reenters with forceps or a cystotome to enlarge the CCC to an appropriate size (typically 5 mm to 5.5 mm in diameter).
Even with adequate decompression, the anterior capsule remains fragile. Therefore, using a high-viscosity cohesive OVD is helpful to flatten the anterior capsule and tamponade any pressure gradient. Forceps are generally preferred over a cystotome for rhexis completion due to improved control (Figure 1). However, the surgeon must be prepared to frequently reinject OVD to maintain chamber stability, particularly in eyes with positive pressure or shallow anterior chambers.
Phacoemulsification in intumescent cataracts also requires special considerations. The nucleus is often dense and large, with minimal cortical support. The capsular bag is often more mobile due to the liquefied cortex, and the zonules may be weakened from chronic lens swelling. Torsional or longitudinal phaco power should be titrated to avoid thermal injury and surge, and phaco vacuum levels may need to be moderated due to the unstable capsular bag.
Hydrodissection must be approached with caution. In traditional cataract surgery, hydrodissection helps separate the nucleus from the capsule, facilitating rotation and removal. However, in the setting of intumescent cataracts, aggressive hydrodissection can lead to capsular rupture due to the buildup of posterior pressure. Instead, minimal and segmented hydrodissection -- or even hydrodelineation only -- is often safer. Once the nucleus is mobilized, rotation should be done gently and only after confirming that the nucleus is freely mobile.
Another risk during phacoemulsification of these dense lenses is zonular stress or dehiscence. If the nucleus is bulky or not easily rotated, the surgeon should avoid excessive manipulation and instead consider chopping techniques that minimize rotation, such as horizontal chop or phaco prechop. Capsule tension rings may be placed intraoperatively if zonular weakness is suspected to stabilize the bag during lens fragmentation and IOL insertion. Alternatively, capsular hooks may be employed temporarily to support the bag.
Once the nucleus is removed, cortical cleanup is generally easier than with typical cataracts because much of the cortex is already liquefied and aspirated earlier in the case. However, care must be taken to avoid aspiration near any areas of suspected zonular weakness. Using bimanual irrigation and aspiration allows for better control and access to cortical remnants without stressing the capsule.
IOL insertion should be planned in advance. If the capsule is intact and the capsulorrhexis is well centered and appropriately sized, in-the-bag placement is ideal. However, in cases with capsular compromise, sulcus placement with or without optic capture may be required. If both the anterior and posterior capsules are compromised, anterior chamber IOLs or scleral-fixated IOLs become considerations, although these are rarely required with careful technique.
In summary, cataract surgery on an intumescent white lens demands a methodical and cautious approach centered around managing intralenticular pressure, maintaining chamber stability and preserving capsular integrity. A stepwise decompression strategy, supported by cohesive OVDs and meticulous capsulorrhexis technique, is essential to avoid anterior capsule tears. Phacoemulsification should emphasize techniques that reduce zonular stress and avoid aggressive hydrodissection. With proper intraoperative planning, including readiness for capsular support devices and alternate IOL placement strategies, excellent visual outcomes can be achieved even in these high-risk cases.
A video of this can be found at https://cataractcoach.com/category/white-cataracts/.