2020–2021 BCSC Basic and Clinical Science Course™
11 Lens and Cataract
Chapter 12: Preparing for Cataract Surgery in Special Situations
Altered Lens and Zonular Anatomy
Iris Coloboma and Corectopia
Zonular dehiscence or absence commonly occurs in the area of iris coloboma (Fig 12-7A) or a misshapen pupil. Pharmacologic dilation can be carried out to assess the extent of zonular abnormality. Iris hooks can be used intraoperatively to pull a flaccid iris out of the way. A capsular tension ring (CTR) that incorporates a coloboma diaphragm (Fig 12-7B) helps stabilize the capsular bag and serves as an artificial iris diaphragm. The surgeon also has the option of repairing the coloboma with a suture at the conclusion of the case. When the iris defect is sufficiently large to indicate the use of a prosthesis, the surgeon can implant an artificial iris.
Excerpted from BCSC 2020-2021 series: Section 11 - Lens and Cataract. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.