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Improved IOL power prediction utilising swept source OCT

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Session Details

Session Title: Cataract Surgery Outcomes: IOL Power Calculations

Session Date/Time: Sunday 08/10/2017 | 14:30-16:00

Paper Time: 14:36

Venue: Meeting Center Room I

First Author: : G.Barrett AUSTRALIA

Co Author(s): :    O. Findl   E. Fabian   J. Jorgensen              

Abstract Details


To compare the error in spherical and astigmatic prediction with the Barrett Universal II (BUII) formula using standard keratometry or the True Keratometric Power (TKP) of the cornea measured with a biometer based on swept source OCT in post Lasik eyes and normal eyes undergoing cataract surgery.


Research Institute (Lions Eye Institute) and Private Practice, Perth Western Australia Vienna Hanusch Hospital , Austria Augencentrum Rosenheim, Germany Euro Eyes Eye Laser Clinic in Hamburg


The error in predicted spherical equivalent refraction and predicted residual astigmatism was compared in a series of 83 eyes provided by two surgeons retrospectively using the BUII formula with and without the addition of the measured post cornea by swept source OCT. In addition the measured TKP after Lasik was compared to the calculated true corneal power and the predicted corneal power by the Barrett True K formula in another 30 eyes.


The mean and median absolute error in spherical power prediction were less and the percentage predicted within 0.5 D improved from 76% to 82% with incorporation of the measured post cornea (TKP). The predicted error in residual astigmatism using a method that did not account for the posterior cornea was 35.3% compared to 67.6% using the Barrett Toric calculator utilising the measured posterior cornea and 76.5% within 0.5 D utilising a predicted value for the posterior cornea. The corneal power utilising the measured TKP value post Lasik was similar to the predicted Corneal power using the True K formula.


The study demonstrated the potential for measurements of the posterior corneal power to improve the prediction in spherical astigmatic and post Lasik outcomes.

Financial Disclosure:

gains financially from product or procedure presented, receives consulting fees, retainer, or contract payments from a company producing, developing or supplying the product or procedure presented

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