title: Effect of square-edged intraocular lenses on neodymium:YAG laser capsulotomy rates in the United States.
abstract: OBJECTIVE
  To model the effect of the introduction of square-edged intraocular lenses (IOLs) in the United States on neodymium:YAG (Nd:YAG) laser capsulotomy rates and to compare the model with actual capsulotomy rates.
  
  
  METHODS
  Ophthalmology Department, St. Thomas' Hospital, London, United Kingdom, and Cullen Eye Institute, Baylor College of Medicine, Houston, Texas, USA.
  
  
  METHODS
  The actual numbers of cataract surgeries and Nd:YAG laser capsulotomies performed in the U.S. were obtained from Medicare claims data for 1993 to 2003. The percentage market share of square-edged IOLs was obtained, and numbers of square-edged and round-edged IOLs implanted were calculated. Predicted laser capsulotomy rates were modeled on published postmortem and clinical data and compared with actual capsulotomy rates.
  
  
  RESULTS
  Between 1993 and 2003, the number of cataract surgeries and Nd:YAG laser capsulotomies reimbursed by Medicare rose by 67.4% and 18.9%, respectively. After the introduction of square-edged IOLs in 1995, the market share grew to 48.5% in 2003. The total number of Nd:YAG capsulotomies reimbursed by Medicare in 2003 exceeded the number of capsulotomies predicted by the model by at least 23.9%. The estimated cost generated by the discrepancy between predicted and actual laser capsulotomies in 2003 was at least US $30 million.
  
  
  CONCLUSIONS
  After the introduction of square-edged IOLs, Nd:YAG laser capsulotomy rates decreased, but not by as much as predicted. The additional cost to the Medicare system was more than US $30 million higher than the model predicted.
authors.affiliation: Ophthalmology Department, St. Thomas' Hospital, London, United Kingdom.
authors.forename: Georgia
authors.initials: G
authors.lastname: Cleary
authors.forename: David J
authors.initials: DJ
authors.lastname: Spalton
authors.forename: Douglas D
authors.initials: DD
authors.lastname: Koch
mesh_terms: D000179:Acrylates; D000368:Aged; D002386:Cataract / Q000628:therapy; D002387:Cataract Extraction / Q000706:statistics & numerical data*; D006801:Humans; D007344:Insurance Claim Reporting / Q000706:statistics & numerical data; D053685:Laser Therapy / Q000706:statistics & numerical data*; D007903:Lens Capsule, Crystalline / Q000601:surgery*; D019654:Lens Implantation, Intraocular; D007910:Lenses, Intraocular; D006278:Medicare / Q000706:statistics & numerical data*; D011183:Postoperative Complications; D011474:Prosthesis Design; D012086:Reoperation; D014481:United States / Q000453:epidemiology
chemical_list: D000179:Acrylates; C036658:acrylic acid