title: Accuracy in determining intraocular lens dioptric power assessed by interlaboratory tests.
abstract: OBJECTIVE
  To describe a testing program conducted by a standards group as a guide for setting international tolerances for intraocular lens (IOL) dioptric power.
  
  
  METHODS
  Multicenter study.
  
  
  METHODS
  Seven biconvex, poly(methyl methacrylate) IOLs ranging in power from 10.00 through 30.00 diopter (D) were circulated among nine participating laboratories experienced in IOL optical measurements. Each laboratory performed repeated optical tests to determine dioptric power. These results were analyzed for repeatability and reproducibility in accordance with methods specified by the International Organization for Standardization.
  
  
  RESULTS
  Intralaboratory repeatability was less than 0.5% of the dioptric power, and interlaboratory reproducibility, when following a normalized procedure for correction and conversion, was less than 1.0% of the dioptric power.
  
  
  CONCLUSIONS
  Tolerance limits of +/0 0.30 D in the range 0 to 15.00 D, +/- 0.40 D for 15.50 to 25.00 D, and +/- 0.50 D for 25.50 to 30.00 D have been proposed as an international standard for IOLs. The contribution of IOL power error within the limits of the standard are estimated to contribute less than 1.0% to the total error in postoperative refractive prediction.
authors.affiliation: Pharmacia Production BV, Groningen, The Netherlands.
authors.forename: N E
authors.initials: NE
authors.lastname: Norrby
authors.forename: L W
authors.initials: LW
authors.lastname: Grossman
authors.forename: E P
authors.initials: EP
authors.lastname: Geraghty
authors.forename: C F
authors.initials: CF
authors.lastname: Kreiner
authors.forename: M
authors.initials: M
authors.lastname: Mihori
authors.forename: A S
authors.initials: AS
authors.lastname: Patel
authors.forename: V
authors.initials: V
authors.lastname: Portney
authors.forename: D M
authors.initials: DM
authors.lastname: Silberman
mesh_terms: D007910:Lenses, Intraocular / Q000592:standards*; D008768:Methylmethacrylates; D009885:Ophthalmology / Q000379:methods*; D055095:Optics and Photonics; D015203:Reproducibility of Results
chemical_list: D008768:Methylmethacrylates