Posterior capsular opacification and intraocular lens decentration. Part I: Comparison of various posterior chamber lens designs implanted in the rabbit model.

Experimental phacoemulsification procedures were performed in 54 Rex rabbits. In 96 eyes, posterior chamber intraocular lenses (IOLs) were implanted in the capsular sac, and 12 eyes served as controls with no lens implantation. The IOLs were divided into eight groups consisting of both one-piece and three-piece styles with various optic designs. Each lens was evaluated for the relative effect on posterior capsular opacification (PCO) and optic decentration, two of the most common complications of modern cataract surgery and IOL implantation. Optics with a convex-anterior, plano-posterior design (the type of IOL optic most frequently implanted today) had the highest incidence of PCO. With capsular fixated IOLs, the features that have a statistically significant impact on reducing PCO include (1) one-piece, all-polymethylmethacrylate (PMMA) IOL styles, (2) a biconvex or posterior convex optic design, and (3) angulated loops. Lens decentration was not affected by the optic design, but statistical analysis showed that one-piece, all-PMMA IOL construction provided the most consistent centration.