[Morphology of capsular sack retraction in relation to capsulotomy technique, lens design and sulcus-/saccus...

Over a period of several months the dynamics and morphology of capsular retraction were analyzed with various capsulotomy techniques and IOL types implanted into the capsular bag or the sulcus. The techniques compared were peripheral and intermediate canopener capsulotomy, intermediate and small letter-box capsulotomy, intermediate and small capsulorrhexis with and without superior incisions. The posterior chamber IOLs implanted were one-piece and three-piece C-loop lenses and, in a limited pilot study, one-piece disk lenses. The authors' results indicate that capsular retraction and the stable position of the implant depend on the type, form, and size of the capsulotomy, the type of IOL and its fixation in the bag or sulcus. Any irregularity of the anterior capsule induces irregular capsular retraction with the risk of IOL decentration. Free-floating anterior capsular flaps may induce formation of iridocapsular synechiae. Contact between the anterior capsular rim and the posterior capsule results in capsulocapsular adhesions, capsular wrinkling, and capsular opacification of the contact zone. In order to avoid these capsulocapsular adhesions the diameter of the IOL optics should exceed that of the capsular opening in endocapsular implantation. However, peripheral capsulocapsular adhesions are necessary to stabilize IOL haptics, which for this reason must be of open design. Capsulocapsular adhesions may inhibit migration of lens epithelial cells in secondary capsular opacification. The ideal anterior capsulotomy technique seems to be the symmetrical, small, circular, continuous capsulorrhexis, if endocapsular implantation is desired. However, the technique is mainly designed for phacoemulsification, as a small capsulorrhexis inhibits nuclear expression in extracapsular cataract extraction.(ABSTRACT TRUNCATED AT 250 WORDS)