Official ESCRS | European Society of Cataract & Refractive Surgeons
Vienna 2018 Delegate Registration Programme Exhibition Virtual Exhibition Satellites 2018 Survey


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Accuracy of total corneal topographic astigmatism (CorT total) compared to the total corneal power measured using 3 different tomographers

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Session Details

Session Title: Vision & Accommodation Assessment

Session Date/Time: Monday 24/09/2018 | 14:00-16:00

Paper Time: 14:12

Venue: Room A3, Podium 2

First Author: : N.Alpins AUSTRALIA

Co Author(s): :    J. Ong   J. Randleman                 

Abstract Details


To compare the total corneal topographic astigmatism (CorT total) to the manufacturer’s total corneal power measured from the Ziemer Galilei, CSO Sirius and Oculus Pentacam tomographers.


NewVision Clinics, 7 Chesterville Road, Cheltenham VIC, 3192 Australia


The CorT parameter (CorT total) is calculated using all the data, including posterior cornea, captured during tomography. The CorT total was then compared to the total corneal powers generated from the Galilei, the CSO and the Pentacam tomographers using the spread of the ocular residual astigmatism (ORA), which quantifies corneo-refractive differences. A low standard deviation of the ocular residual astigmatism (ORAsd) indicates a low variability between corneal astigmatism and refractive cylinder, magnitude and orientation. A low mean of the ocular residual astigmatism magnitude indicates a close correlation of refractive and corneal astigmatism magnitudes.


The mean ORA magnitude for the CorT total measured by the CSO (n=606) was 0.51D, 0.66D for the Galilei Z4 (n=190) and for the Pentacam (n=197) 0.64D. The ORAsd for the CSO was 0.32D, 0.47D for the Galilei and 0.34D for the Pentacam. The mean ORA magnitude of the total corneal power by the CSO was 0.53D, 0.63D for the Galilei and 0.63D for the Pentacam.


The CorT total is comparable to the total corneal powers measured by the Galilei, Sirius and Pentacam tomographers. The CorT total can be used across different tomographers as an accurate and reliable measure of total corneal astigmatism when planning toric IOL surgery or corneal surgery associated with correcting astigmatism.

Financial Disclosure:

... gains financially from product or procedure presented

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