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Prediction of refractive outcomes using the new PhysIOL Toric calculator adjusted by the Abulafia-Koch formula

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Session Details

Session Title: Presbyopia Management

Session Date/Time: Sunday 08/10/2017 | 16:30-18:00

Paper Time: 17:21

Venue: Room 2.1

First Author: : K.Nistad NORWAY

Co Author(s): :    O. Lundstroem                    

Abstract Details


To evaluate and compare the accuracy (prediction of refractive outcomes) of two commercial toric intraocular lens (IOL) calculators after toric IOL implantation in Refractive lens exchange (RLE) in high volume clinics: The standard PhysIOL Toric calculator, and the new version adjusted by the Abulafia-Koch formula, which theoretically accounts for posterior corneal astigmatism.


Memira, Scandinavian–based private refractive surgery clinics. Norway.


The study reviewed case records of consecutive patients who had RLE with trifocal toric IOL (FineVision toric, PhysIOL, Belgium) implantation by multiple surgeons. The predicted residual astigmatism for the standard and the new PhysIOL toric IOL calculators (Abulafia-Koch formula option turned on) was calculated by using the preoperative measurements of the IOLMaster500 device, the routine SIA values for each surgeon and the intended IOL axis. Visual acuity and refraction data were collected 3 months postoperative. The error in the predicted residual astigmatism (prediction error) was calculated by subtracting the predicted residual astigmatism from the 3-month postoperative refraction cylinder.


Data from 634 eyes were available for analysis. The centroid errors in predicted residual astigmatism were against-the-rule with the standard toric calculator 0.48D @ 175° and with-the-rule with the new toric calculator (using Abulafia-Koch formula) 0.14D @ 110° (P < .0001). The new toric calculators had lower mean absolute errors (0.49D ± 0.34D) as compared to the standard calculator (0.67D ± 0.37D), P<0.0001, and a higher proportion of eyes within 0.50, 0.75 and 1.0 D prediction error (59.3%, 81.7% and 92.9% Vs 34.5%, 66.1% and 84.2% respectively), P<0.0001. The mean CDVA was -0.04 ± 0.07 logMAR.


Based on the clinical outcomes of this high volume setting, the new commercial toric IOL calculator adjusted by the Abulafia-Koch formula significantly improved the prediction of postoperative astigmatic outcome. Overall, the implanted trifocal toric IOLs led to a significant improvement of astigmatism with a very good restoration of visual acuity.

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