Gender differences in biometry prediction error and intra-ocular lens power calculation formula

2014 ◽  
Vol 92 (8) ◽  
pp. 759-763 ◽  
Author(s):  
Anders Behndig ◽  
Per Montan ◽  
Mats Lundström ◽  
Charlotta Zetterström ◽  
Maria Kugelberg
Keyword(s):  
Gender Differences ◽  
Prediction Error ◽  
Power Calculation ◽  
Calculation Formula ◽  
Ocular Lens ◽  
Lens Power ◽  
Lens Power Calculation

Microincision cataract surgery with implantation of a bitoric intraocular lens using an enhanced program for intraocular lens power calculation

2019 ◽  
Vol 30 (6) ◽  
pp. 1308-1313
Author(s):  
Gilles Lesieur
Keyword(s):  
Cataract Surgery ◽  
Intraocular Lens ◽  
Prediction Error ◽  
Power Calculation ◽  
Spherical Equivalent ◽  
Toric Intraocular Lens ◽  
Intraocular Lens Power Calculation ◽  
Intraocular Lens Power ◽  
Lens Power ◽  
Lens Power Calculation

Purpose: To evaluate the potential benefit of a new version of an online toric intraocular lens calculator in eyes implanted with a bitoric intraocular lens. Patients and methods: Retrospective observational comparative study in patients that underwent cataract surgery with implantation of the bitoric intraocular lens AT TORBI 709M (Carl Zeiss Meditec AG, Jena, Germany). Visual and refractive outcomes were evaluated at 1 month after surgery. The selection of the toric intraocular lens power was performed with the software Z CALC 2.0 (Carl Zeiss Meditec AG). The absolute refractive prediction errors for the spherical equivalent and cylinder were calculated and compared with the values that would have been obtained using version 1.5 of the same software. Results: A total of 393 eyes of 276 patients were evaluated. Mean postoperative sphere and cylinder were +0.03 ± 0.54 and −0.19 ± 0.30 D, respectively. A total of 95.67%, 98.22%, and 95.17% of eyes had a postoperative sphere, cylinder, and spherical equivalent within ±1.00 D, respectively. Mean absolute refractive prediction error for spherical equivalent was 0.34 ± 0.27 D with the two versions of the Z CALC software. In contrast, a significantly higher absolute refractive prediction error value for the cylinder was found with Z CALC 1.5 compared to version 2.0 (0.35 ± 0.32 vs 0.28 ± 0.30 D, p < 0.001). The absolute refractive prediction error for cylinder was ⩽0.25 D in 62.3% and 47.5% when using the versions 2.0 and 1.5, respectively. Conclusion: The use of an optimized software for toric intraocular lens power calculation, considering the contribution of posterior corneal astigmatism, improved the astigmatic outcome with a bitoric intraocular lens.

scholarly journals Accuracy of intraocular lens power calculation formulas after laser refractive surgery in myopic eyes: A meta-analysis

2019 ◽  
Author(s):  
Hongyu Li ◽  
Jun Li ◽  
Hui Song
Keyword(s):  
Intraocular Lens ◽  
Prediction Error ◽  
Refractive Surgery ◽  
Meta Analysis ◽  
Cochrane Library ◽  
Power Calculation ◽  
Intraocular Lens Power Calculation ◽  
Intraocular Lens Power ◽  
Lens Power ◽  
Lens Power Calculation

Abstract Background: To compare the accuracy of intraocular lens power calculation formulas after refractive surgery in myopic eyes. Methods: We searched the databases on the PubMed, EMBASE, Web of science and Cochrane library to select relevant studies published between Jan 1, 2009 and Aug 11, 2019. Primary outcomes were the percentages of refractive prediction error within ±0.5D and ±1.0D. Results: The results of this meta-analysis were investigated from 16 studies, including 7 common methods (Haigis-L, Shammas-PL, Double-K SRK/T, Barrett true K no history, Wang-Koch-Maloney, ASCRS average and OCT formula). ASCRS average yielded significantly higher percentage of refractive prediction error within ±0.5D than Haigis-L, Shammas-PL and W-K-M (P=0.009, 0.01, 0.008, respectively). Barrett true K no history also yielded significantly higher percentage of refractive prediction error within ±0.5D than Shammas-PL and W-K-M (P=0.01, <0.0001, respectively), and the same result was found by comparing OCT formula with Hiaigi-L and Shammas-PL (P=0.03, 0.01, respectively). Only the Haigis-L had significantly higher percentages than W-K-M method in the ±1.0D group (P = 0.04). Conclusion: We suggest that the ASCRS average and Barrett true K no history formula should be used to calculate the IOL power in eyes after myopic refractive surgery.

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