Looking at this image should intimidate beginning cataract surgeons: this is a whitish-brown totally opaque cataract and it is a challenge even for expert surgeons. The good news is that there is unlikely to be intumescent fluid within the capsular bag, so we should be able to make a good capsulorhexis after staining the capsule with Trypan blue dye. The bad news is that this nucleus is dense, really dense. Almost like a rock. What some surgeons call a “cata-rock” and the biggest challenge will be the posterior plate of the lens nucleus. The posterior aspect of the lens has a leathery, fibrous plate that is not easily split.
When we perform standard vertical chop, horizontal chop, stop-and-chop, or even divide-and-conquer, the crack that we create in the lens nucleus is unable to propagate all the way through and instead of having two fully split halves, we are left with the nucleus still attached at the bottom. This makes for a protracted struggle as this toughest part is right up against the delicate posterior capsule.
If we bring the nucleus partially out of the capsular bag, we can place our chopper under the dense posterior plate and then successfully split it first, then have the crack propagate towards the anterior of the cataract nucleus. This works well because it directly addresses the dense posterior plate first and once that is broken up, the rest of the nucleus removal is far easier.
The key to bringing the nucleus out of the capsular bag is to have a sufficiently large capsulorhexis. If you have made a small 4 or 4.5 mm diameter capsulorhexis, then you will not be able to accomplish this. Instead, aim for a diameter of 5.5 mm or even slightly larger. This will allow the nucleus to prolapse out of the capsular bag during hydrodissection or viscodissection. If you make a 6 or 6.5 mm diameter capsulorhexis, do not worry that the edge doesn’t fully overlap the optic. As the capsule shrink-wraps in the post-op period, the overall capsular opening diameter will shrink by about 1 mm and it will overlap it just fine.
click below to see this technique demonstrated in an unedited surgical video: