We often encounter patients with Pseudo-Exfoliation Syndrome, often abbreviated as PXF, which makes cataract surgery significantly more challenging. The PXF material becomes deposited throughout the anterior segment of the eye and we can see this on slit-lamp microscopic examination.
This whitish fibrillar material is deposited on the anterior lens capsule where it is seen centrally as well as towards the lens periphery and on the pupil margin. There is a zone of clearing without PXF material on the anterior lens capsule because the pupil margin touches and rubs this area thereby preventing deposits from adhering. In cases of severe pseudo-exfoliation, the pupil dilation may be limited and these zones may not be fully visualized. Also note that PXF tends to affect one eye more than the other.
One of the most important measurements in the pre-operative testing is the anterior chamber depth in relation to the axial length. In the case presented here, in the right eye, which has extensive PXF, the anterior chamber depth is 2.92 mm with an axial length of 23.40 mm. The patient has a history of anisometropia with the other eye having a shorter axial length of 22.13 mm but a deeper anterior chamber of 3.25 mm.
For cataract surgery in patients with pseudo-exfoliation, I recommend a sufficiently large capsulorhexis of at least 5 mm in diameter since these patients tend to get capsular phimosis. Placement of a capsular tension ring may help in select cases, but it is no guarantee of future stability. These PXF patients may end up with late-stage dislocation of the entire lens and capsule structure into the vitreous cavity. This tends to occur a decade or longer after the initial cataract surgery can can be remedied by various techniques of IOL fixation.
Bringing the cataract partially out of the capsular bag can help to minimize stress on the zonular support while disassembling the nucleus. For IOL placement, a single-piece acrylic IOL can work very well in most cases whereas in select other cases a three-piece IOL may offer more options for placement. The single-piece acrylic IOL can be placed in the capsular bag. The three-piece IOL can be placed in the bag, in the sulcus, or via optic capture with the optic behind the capsulorhexis and the haptics in the sulcus.
Click below to watch a successful approach to cataract surgery in pseudo-exfoliation: