title: Effect of a closed foldable equator ring on capsular bag shrinkage in cataract surgery.
abstract: OBJECTIVE
  To evaluate the effect of a closed foldable equator ring (CFER) versus a conventional capsular tension ring (CTR) on capsular bag shrinkage.
  
  
  METHODS
  Department of Ophthalmology, Johannes Gutenberg-University, Mainz, Germany.
  
  
  METHODS
  In this prospective study, 70 eyes of 70 patients were randomized to 2 groups using a 1:1 block scheme. After uneventful cataract surgery, a capsular measuring ring was implanted in all eyes to measure the capsular bag diameter in vivo. In Group 1, a CTR was implanted in the capsular bag. In Group 2, a CFER was inserted. Biometric characteristics such as axial length and the horizontal and vertical corneal radii were measured preoperatively. The capsular bag diameter and capsulorhexis diameter were measured intraoperatively and 2 or 3 days as well as 1 and 3 months postoperatively.
  
  
  RESULTS
  There were no statistically significant or clinically relevant between-group differences in covariants such as axial length, vertical and horizontal corneal radii, and capsulorhexis diameter. Eyes with the CTR had slight but statistically significant capsular bag shrinkage from a median of 10.4 to a median of 10.2 mm after 3 months (P<.001). Eyes with the CFER also had slight but statistically significant capsular bag shrinkage from a median of 10.3 to a median of 10.2 mm 3 months postoperatively (P = .021). At baseline, the CTR group had a larger capsular bag diameter, but there were no statistically significant differences between the groups at the 3-month follow-up (P = .669).
  
  
  CONCLUSIONS
  No clinically relevant capsular bag shrinkage was observed after implantation of a CFER or a CTR. The expected capsular bag shrinkage was the same in both groups.
authors.affiliation: Department of Ophthalmology, Johannes Gutenberg-University, Mainz, Germany. kurz@augen.klinik.uni-mainz.de
authors.forename: Sabine
authors.initials: S
authors.lastname: Kurz
authors.forename: Frank
authors.initials: F
authors.lastname: Krummenauer
authors.forename: Carolin
authors.initials: C
authors.lastname: Dumbach
authors.forename: Norbert
authors.initials: N
authors.lastname: Pfeiffer
authors.forename: H Burkhard
authors.initials: HB
authors.lastname: Dick
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D007431:Intraoperative Complications; D007903:Lens Capsule, Crystalline / Q000601:surgery*; D019654:Lens Implantation, Intraocular / Q000379:methods*; D008297:Male; D008689:Methacrylates; D020366:Methylmethacrylate; D018918:Phacoemulsification / Q000379:methods*; D019904:Polymethyl Methacrylate; D011183:Postoperative Complications; D011446:Prospective Studies; D019736:Prostheses and Implants; D019919:Prosthesis Implantation
chemical_list: D008689:Methacrylates; D020366:Methylmethacrylate; C005044:hydroxyethyl methacrylate; D019904:Polymethyl Methacrylate