Predicting the lens capsular bag size using pre-operative biometry

Toric IOLs are used to correct corneal astigmatism which is present in moderate to high amounts in approximately one third of patients coming for cataract surgery (Hoffmann et al). One uncertainty with toric IOL is the behaviour of the lens capsular bag as it has an influence on IOL position and rotational stability of the IOL. One possibility to measure the capsular bag diameter after surgery is to use a capsular tension ring, which is implanted in the eye during cataract surgery and to measure the distance of the two ends of the ring using gonioscopy. Aim of this study is to assess whether a high-resolution scan of the crystalline lens before surgery may be helpful in predicting post-operative capsule bag diameter.