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Challenges in treating the many manifestations of white cataracts
The many manifestations of white cataracts make phacoemulsification challenging. The nuclei of white cataracts can be hard or soft. Intracapsular pressure can be high or low. Onset can be acute or long-term.
 Armando Crema |
In hypermature Morgagnian cataracts, the intracapsular pressure can be extremely low; in intumescent cataracts, the intracapsular pressure can be extremely high. The cataracts can be acute and inflammatory, occurring after uveitis or trauma, or they can be longstanding mature white lenses with hard consistency. Acute white cataracts strongly suggest a posterior capsular rupture during a previous vitreoretinal surgery.
Although the slit lamp examination can show a shallow anterior chamber and a hypertensive capsular bag, Scheimpflug imaging is an important tool for quantifying the hypertension and measuring the anterior chamber depth.
"In these white cataract cases, the risk for incision burns, endothelial trauma and capsular rupture is greater."
— Armando Crema, MD
Intumescent cataracts are the most challenging to remove, because the higher intracapsular pressure can make the anterior capsular flap run to the equator during capsulorrhexis. When this occurs and when trypan blue dye has been used to enhance visualization, the resulting complication is called the Argentinean flag syndrome. The resulting band-of-blue, band-of-white, band-of-blue pattern seen where white cortex shows through the tear resembles the Argentinean flag—hence the name.
Creating capsulorrhexis
Because of the poor red reflex in white cataract eyes, capsulorrhexis used to be difficult, but the staining of the anterior capsule with dyes such as trypan blue was the turning point that facilitated this surgical step. Generally, trypan blue is injected through the side port incision under an air bubble.
To avoid the Argentinean flag syndrome, I create the capsulorrhexis in two steps. First, I make a small circular anterior capsule opening (Figure 1) in an anterior chamber filled with viscodispersive (ophthalmic viscosurgical device, or OVD). Then, I use hydrodissection and nucleus rotation to free the anterior and posterior cortical material from the capsular bag, lowering the capsular bag pressure. After refilling the anterior chamber with the same OVD, I finish by enlarging the capsulorrhexis to the ideal size using Vannas scissors and forceps (Figure 2).
 Figure 1. Two-step capsulorrhexis: small capsular opening. |
 Figure 2. Two-step capsulorrhexis: enlarged capsular opening. |
Emulsification
Emulsification is also challenging, mostly because of the hardness of the nucleus and the absence of a posterior epinucleus to protect the posterior capsule. In these white cataract cases, the risk for incision burns, endothelial trauma and capsular rupture is greater.
To maximize surgical outcomes for these patients, I use the Infiniti Vision System with the Intrepid Fluidic Management System and OZil torsional ultrasound (Alcon Laboratories, Inc.). This combination allows me to safely create a 2.2-mm temporal clear corneal microincision and avoid chatter of nuclear pieces. Furthermore, total ultrasound power time and cumulative dissipated energy are reduced, and anterior chamber surge is prevented.
Differently than traditional longitudinal ultrasound, torsional ultrasound maintains a low level of mechanical stress during phaco because of less repulsion and chattering. Generally, I use a vertical chop technique (Figure 3), and for chopping the nucleus I use 110-cm H2O irrigation, 350-mm Hg vacuum, 35-cc/min flow rate and 0% to 100% linear amplitude for torsional ultrasound. After dividing the nucleus, for aspiration and emulsification of the pieces, I use 110-cm H2O irrigation, 250-mm Hg vacuum, 30-cc/min flow rate and 30% to 100% linear amplitude for torsional ultrasound. To effectively use torsional ultrasound, I use a 45° Kelman mini-flared tip (Alcon Laboratories, Inc.). With this phaco tip, torsional ultrasound is maximized and even in an extremely hard nucleus nuclear pieces do not clog the tip (Figure 4).
 Figure 3. Vertical chopping. |
 Figure 4. Emulsification and aspiration of the pieces. |
Any aspheric AcrySof single-piece IOL (Alcon Laboratories, Inc.) can be inserted through a 2.2-mm microincision using a D-cartridge and a Monarch III injector (Alcon Laboratories, Inc.), although ReSTOR IOLs (Alcon Laboratories, Inc.) may be contraindicated in some patients because it can be difficult to adequately preoperatively evaluate the macula and optic nerve in these complicated cataracts.
Dr. Crema is assistant professor at Gama Filho University in Rio de Janeiro, Brazil.
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