title: Capsular bag shrinkage after implantation of a capsular bending or capsular tension ring.
abstract: OBJECTIVE
  To evaluate the influence of a capsular bending ring (CBR) or tension ring (CTR) on capsular bag shrinkage.
  
  
  METHODS
  Department of Ophthalmology, Johannes Gutenberg-University, and Department of Medical Biometry, Epidemiology and Informatics, University of Mainz, Mainz, Germany.
  
  
  METHODS
  In 92 eyes of 92 patients, a capsular measuring ring (CMR) was implanted after phacoemulsification to measure capsular bag size in vivo. Patients were randomized into 3 groups: The first received a CMR and CBR, the second received a CMR and CTR, and the third received a CMR alone. Measurements were performed preoperatively, intraoperatively, during the first 3 postoperative days, and after 1 and 3 months. Preoperative biometric characteristics such as axial length (AL) and anterior chamber depth were determined. Primary clinical end points were capsular bag size and capsulorhexis diameter measured intraoperatively and by means of slitlamp biomicroscopy and retroillumination photography postoperatively.
  
  
  RESULTS
  There were no clinically relevant group differences in AL, anterior chamber depth, or capsulorhexis diameter. Eyes implanted with the CBR showed shrinkage of the capsular bag from 10.6 to 10.4 mm after a median of 3 months (sign test; P = .023); eyes with a CTR showed comparable median capsular bag shrinkage from 10.5 to 10.2 mm (P<.001), whereas eyes without a CTR showed a median shrinkage from 10.5 to 10.0 mm (P<.001). Intraindividual shrinkage was of a similar, although significantly different, order among these groups (median shrinkage 0.15 versus 0.23 and 0.38 mm, respectively; all pairwise Wilcoxon test; P = .050, P = .020, P<.001, respectively).
  
  
  CONCLUSIONS
  Capsular shrinkage can be inhibited by a CBR and, to lesser extent, a CTR; the gain in shrinkage prevention is limited when compared with a CMR, however. This conclusion can be drawn only for the specific CBR or CTR and hydrophobic acrylic intraocular lens (IOL) used in this study. Reduction of capsular bag shrinkage after CTR implantation may reduce IOL dislocation and tilt and help to maintain postoperative visual acuity.
authors.affiliation: Department of Ophthalmology, Johannes Gutenberg-University, Mainz, Germany.
authors.forename: Sabine
authors.initials: S
authors.lastname: Kurz
authors.forename: Frank
authors.initials: F
authors.lastname: Krummenauer
authors.forename: Philipp
authors.initials: P
authors.lastname: Hacker
authors.forename: N
authors.initials: N
authors.lastname: Pfeiffer
authors.forename: H Burkhard
authors.initials: HB
authors.lastname: Dick
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001699:Biometry; D002387:Cataract Extraction; D004867:Equipment Design; D006801:Humans; D007903:Lens Capsule, Crystalline / Q000473:pathology* / Q000601:surgery*; D019654:Lens Implantation, Intraocular; D008855:Microscopy, Electron, Scanning; D008875:Middle Aged; D018918:Phacoemulsification; D019736:Prostheses and Implants