title: The effect of polymethylmethacrylate and acrysof intraocular lenses on the posterior capsule in patients with a large capsulorrhexis.
abstract: OBJECTIVE
  We have previously shown that patients who have a capsulorrhexis larger than the diameter of a polymethylmethacrylate (PMMA) intraocular lens (IOL) rapidly develop increased posterior capsule opacification (PCO), in effect, producing an example of enhanced PCO. This study focuses on the influence of AcrySof IOLs on this process.
  
  
  METHODS
  Phacoemulsification was performed on two groups of patients. The first consisted of 38 patients with a large capsulorrhexis of 6-7 mm who received a 5.5-mm PMMA IOL. The second group of 32 patients had identical surgery and a 5.5-mm MA30 AcrySof IOL was implanted. On days 1,14, 28, 90, 180, and 360, high resolution digitized retroillumination images were taken of the posterior capsule. The PCO area was measured by image analysis at 90, 180, and 360 days. Wrinkling of the posterior capsule was determined at 90 days, and the progression or regression of lens epithelial cell (LEC) proliferation was established by examination of serial images at 28 and 180 days.
  
  
  RESULTS
  At 90 days, 79% of the patients with PMMA IOLs had moderate to severe wrinkling of the posterior capsule, whereas the patients with AcrySof IOLs had none (P <.001). The percentage of PCO area was 69% for the PMMA IOLs and 24% for the AcrySof IOL group at 360 days (P <.0001). In the PMMA group, LEC progression occurred in 77%, LEC growth was stable in 15%, and LEC regression occurred in only 8%, compared to 69% of patients with AcrySof IOLs (P <.0001).
  
  
  CONCLUSIONS
  In patients with a rhexis larger than the IOL, AcrySof IOLs potentially can prevent capsular wrinkling and cause less PCO than a PMMA IOL with a similar rhexis size. The LEC regression occurs with AcrySof between 28 and 180 days. The reasons for this are discussed.
authors.affiliation: Department of Ophthalmology, St. Thomas' Hospital, London, UK.
authors.forename: W R
authors.initials: WR
authors.lastname: Meacock
authors.forename: D J
authors.initials: DJ
authors.lastname: Spalton
authors.forename: E J
authors.initials: EJ
authors.lastname: Hollick
authors.forename: S
authors.initials: S
authors.lastname: Barman
authors.forename: J F
authors.initials: JF
authors.lastname: Boyce
mesh_terms: D000180:Acrylic Resins; D000368:Aged; D001672:Biocompatible Materials; D019923:Capsulorhexis / Q000379:methods*; D002386:Cataract / Q000209:etiology / Q000517:prevention & control*; D005260:Female; D006801:Humans; D007903:Lens Capsule, Crystalline / Q000473:pathology*; D019654:Lens Implantation, Intraocular; D007910:Lenses, Intraocular; D008297:Male; D018918:Phacoemulsification / Q000379:methods; D019904:Polymethyl Methacrylate
chemical_list: D000180:Acrylic Resins; D001672:Biocompatible Materials; D019904:Polymethyl Methacrylate