title: Comparison of prediction error: labeled versus unlabeled intraocular lens manufacturing tolerance.
abstract: OBJECTIVE
  To compare the prediction error between intraocular lenses (IOLs) available in 0.25 diopter (D) increments with a labeled manufacturing tolerance and IOLs available in 0.50 D increments without a labeled manufacturing tolerance.
  
  
  METHODS
  Community-based multidisciplinary outpatient ophthalmic practices.
  
  
  METHODS
  Comparative case series.
  
  
  METHODS
  Eyes with cataract had implantation of an IOL available in 0.25 D increments and labeled with a manufacturing tolerance of ± 0.11 D (labeled group) or an IOL available in 0.50 D increments without a labeled manufacturing tolerance (unlabeled group). Postoperatively, the prediction error was calculated and compared between groups.
  
  
  RESULTS
  By the SRK/T formula, the mean error of prediction after optimization was -0.03 D ± 0.35 (SD) in the labeled group and -0.05 ± 0.46 D in the unlabeled group (P=.64). The mean absolute error of prediction was statistically significantly smaller in the labeled group (0.26 ± 0.23 D) than in the unlabeled group (0.37 ± 0.28 D) (P=.04). The mean and absolute errors were not statistically significantly different with the Holladay 1 or Hoffer Q formula. Sixty-three percent of patients in the labeled group and 43% in the unlabeled group (P=.03) were within ± 0.25 D of the prediction error; 84% and 69%, respectively, were within ± 0.50 D (P=.06).
  
  
  CONCLUSIONS
  The IOLs available in 0.25 D increments with a labeled manufacturing tolerance of ± 0.11 D increased the percentage of patients within ± 0.25 D of the targeted refraction to a statistically significant and clinically meaningful level compared with unlabeled IOLs available in 0.50 D increments.
  
  
  BACKGROUND
  No author has a financial or proprietary interest in any material or method mentioned.
authors.affiliation: Florida Eye Institute, Vero Beach, Florida 32960, USA. zudans@gmail.com
authors.forename: J Valdis
authors.initials: JV
authors.lastname: Zudans
authors.forename: Neel R
authors.initials: NR
authors.lastname: Desai
authors.forename: William B
authors.initials: WB
authors.lastname: Trattler
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001699:Biometry; D002386:Cataract / Q000150:complications*; D005260:Female; D006801:Humans; D019654:Lens Implantation, Intraocular; D007910:Lenses, Intraocular / Q000592:standards*; D008297:Male; D008420:Manufactured Materials; D008875:Middle Aged; D055095:Optics and Photonics; D018918:Phacoemulsification; D012029:Refraction, Ocular / Q000502:physiology*; D014792:Visual Acuity / Q000502:physiology*