FIGURE 15–1 Photograph of a dense, long-standing posterior polar cataract. Bull’s-eye appearance and cortical extensions are observed. (From Lu LW, Fine IH. Phacoemulsification in Difficult and Challenging Cases. New York: Thieme; 1999:122, Figure 14–2.)

almost sure sign of posterior capsular involvement and of the likelihood of capsular rupture during cataract surgery.

SURGICAL TECHNIQUE

Surgically, soft cataracts are characterized by a minimally dense endonucleus with abundant sticky soft cortical material. The nuclear cortical bag adhesions are usually well developed. Removal of this type of cataract is therefore dependent on separating the sticky cortex from the capsular bag. If this is thoroughly carried out, soft cataracts are usually easy to remove. Removal therefore begins with thorough cortical cleaving hydrodissection. Often, beneficially, the hydrodissection will push the cataract through

the capsulorrhexis and into the anterior chamber (Fig. 15–2). There, the epinucleus and endonucleus are aspirated, with only short bursts of low-power pulsed phaco. No specific divide and conquer or chop technique is required.

COMPLICATIONS

INCOMPLETE HYDRODISSECTION

Complete and thorough hydrodissection is the most important step in removal of the soft cataract. Incomplete hydrodissection will lead to small amounts of cortex adherent to the posterior capsule or in the fornices. This cortex is most easily removed with further hydrodissection or viscodissection prior to or after intraocular lens (IOL) insertion. The cortex can then be removed with the phaco tip in phaco mode or irrigation and aspiration (I&A) mode, or with the I&A tip.

Difficulty mobilizing a large amount of the nucleus is also due to inadequate hydrodissection. When this becomes apparent, the surgeon will phaco what nucleus and cortex is easily accessible. This will result in a large amount of cortex adherent to the capsule. The tendency is to perform phaco near the capsule to remove the sticky cortex. However, phaco near the capsule should be avoided. The sticky cortex often momentarily occludes the phaco tip and is then aspirated with a distinct surge. Due to the dense capsular cortical adhesions, the capsule is pulled into the phaco tip by the cortical-bag connections, essentially caught in the surge. It is instantaneously aspirated and emulsified. The result is a torn posterior capsule with immediate rupture of the vitreous face (Fig. 15–3).

If the cortex appears resistant to removal with the phaco tip, the I&A tip should be substituted. The case may proceed more slowly, due to slow aspiration of the cortex. The anterior chamber will be more stable, however, and tears in the posterior capsule are less likely.

POSTERIOR SUBCAPSULAR CATARACT

One element of the histopathology of a posterior subcapsular cataract (PSC) is posterior migration and fibrosis of lens epithelial cells. When this occurs a plaque of varying density will remain on the posterior capsule after nucleus removal. Occasionally it can be removed with a posterior capsular polishing

FIGURE 15–3 Incomplete hydrodissection. The nuclear cortical bag connections pull the equator into the phaco tip.

instrument. However, if it is recalcitrant, the plaque should be left intact, rather than risk a rupture of the posterior capsule in attempts to remove it. YAG capsulotomy can be performed after an appropriate postoperative period.

POSTERIOR POLAR CATARACT

When performing surgery on any patient with a dense posterior polar cataract, the possibility of posterior capsular thinning or potential capsular rupture must be considered. The patient therefore should be counseled preoperatively that there is an increased incidence of complications and should be given an explanation of the anticipated outcomes.