Managing the hard posterior polar cataract
In the recent article on managing the hard posterior polar cataract,1 Chee described a manual technique in which the periphery of the nucleus was partially cracked with the Nagahara chopper to prevent a posterior capsule (PC) tear. The author believes this method is safer when dealing with a posterior subcapsular cataract (PSC) with a hard nucleus. We agree that this type of cataract is difficult because it is hard to crack the nucleus and easy for a PC tear to occur; in addition, there is not enough space for sufficient hydrodelamination. Some of these lenses are complicated by difficult anterior capsule visualization, posterior subluxation, and loose zonules. We think it may be technically difficult to create a cleavage plane at the nucleus shell as the author suggests. Hydrodelamination is a necessary step to cleave the nuclear plane before proceeding to cracking. However, in our experience, it is technically difficult to correctly identify the “right plane” for hydrodelamination to cleave a plane just anterior to the posterior polar opacity. It is also difficult to judge the depth and completeness of the cleavage after hydrodelamination because lens opacities can obscure the view. The amount of balanced salt solution (BSS) injected to perform the hydrodelamination is important as cataract with PSC usually has a flimsy PC and can be easily ruptured even with the small amount of BSS used in hydrodelamination. This is particularly true when the cataract is hard.
Chee suggested a modified stop-and-chop technique. In our experience, the power and shearing forces in the stop-and-chop techniques can sometimes rock the lens and rupture the PC. We recommend a quick-chop technique to minimize the rocking. After hydrodelamination, quick-chop techniques can be used to create the first 2 quadrants. The core nuclear quadrant can be grasped by the vacuum of the phaco tip. The chopper can then be inserted deep in the lens equator radially toward the center of the lens to create a plane in the lamellae of the nucleus. The tip of the chopper can be rotated into a horizontal position to go through the bottom of the nuclear quadrant, being careful not to rupture the PC and intentionally leave some nucleus with the PSC plaque. The second quadrant can then be removed accordingly. For the heminucleus, the quick-chop technique can be reused to crack the heminucleus into 2 other quadrants. This will avoid rotating the lens and causing a PC tear. However, a larger continuous curvilinear capsulorhexis (5.5 to 6.0 mm) is necessary to facilitate insertion of the instruments and ease of nucleus removal.
In Chee's article, the number of cases performed with this technique is not mentioned and therefore it is not clear whether the approach can be used in nuclei with varying degrees of hardness.
© 2008 by Lippincott Williams & Wilkins, Inc.
1. Chee S-P. Management of the hard posterior polar cataract. J Cataract Refract Surg. 2007;33:1509-1514.