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Updated: May 24, 2026

Comparison of Agreement and Accuracy using Binocular Wavefront Optometer with Autorefractor and Phoropter
Published on: September 16, 2025
Comparison of prediction error: labeled versus unlabeled intraocular lens manufacturing tolerance
J Valdis Zudans1, Neel R Desai, William B Trattler
1Florida Eye Institute, Vero Beach, Florida 32960, USA. zudans@gmail.com
Purpose:
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.
Setting:
Community-based multidisciplinary outpatient ophthalmic practices.
Design:
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).
Conclusion:
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.
Financial Disclosure:
No author has a financial or proprietary interest in any material or method mentioned.
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