Area of zonular absence seen between cataract and iris.
Careful examination shows that this mature white cataract has formed over the course of many years. There is fibrosis and wrinkling of the anterior lens capsule. When instilling trypan blue dye in the eye, the visualization may improve, but it may still be difficult to perform a capsulorrhexis. This fibrotic capsule will not tear the same way as a smooth capsule, and there’s a high probability that micro-scissors, a vitrector or a cystotome will be needed to complete the anterior capsulotomy.
In addition, whenever there is wrinkling of the anterior capsule, it is usually accompanied by zonular weakness. The normal anterior lens capsule is taut like a drumhead due to tension provided by the zonules. In this case, with extensive anterior capsular wrinkling, the zonules are significantly stretched, weak and even absent in quadrants.
When the patient is asked to look inferiorly (See figure), there is a large gap between the cataract and the iris due to zonular loss. This will make the cataract surgery far more difficult with a higher chance of complications.