Official ESCRS | European Society of Cataract & Refractive Surgeons


Comparison of toric intraocular lens prediction using Pentacam, OPD, and IOLMaster measurements

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Session Details

Session Title: Toric IOLs & Lens Power Calculations

Session Date/Time: Sunday 15/09/2019 | 08:00-10:00

Paper Time: 08:00

Venue: Free Paper Forum: Podium 3

First Author: : Q.Kaba UK

Co Author(s): :    E. Tam   R. Maini   S. Somani   H. Chiu                    

Abstract Details


The purpose of this study was to determine and compare the prediction error using IOL Master (IOLM), Pentacam and OPD corneal topography measurements for astigmatism correction using a Toric intraocular lens.


Three-month prospective study. Uptown Eye Clinic, Toronto.


41 eyes of 30 subjects with corneal astigmatism undergoing cataract extraction with toric intraocular lens implantation and no other ocular comorbidities were analysed in this study. Corneal astigmatism was measured preoperatively using IOL Master, OPD, and Pentacam. Residual astigmatism was determined using vector analysis, with comparison of centroid astigmatism error for each of the three topographic methods. Intraclass correlation coefficient was used to determine the similarity between predicted and actual corneal astigmatism. Berdahl Hardten astigmatism fix was also used to measure residual astigmatism. Predicted axis was compared to post-operative axis to determine the measurement method most accurate for axis.


Centroid errors of prediction error in IOLM, Pentacam, and OPD were 0.39@96, 0.36@92, and 0.33@76, respectively, in with-the-rule (WTR) eyes at post-operative month 1 (POM1). They were 0.40@68, 0.33@62, and 0.38@55 for against-the-rule (ATR) eyes, for which Pentacam had the lowest centroid prediction error and the highest ICC (P<0.01) between the predicted and estimated astigmatism. Alternatively, astigmatism fix calculations showed no significant variation in residual astigmatism (P>0.05), with the values 0.16D, 0.10D and 0.13D for OPD, Pentacam, and IOLM respectively at POM1. There was no statistical significance (P>0.05) for actual and predicted axis comparison between IOLM, Pentacam, and OPD.


Pentacam topography resulted in the least corneal astigmatism prediction error, especially in patients with ATR astigmatism. IOL Master showed the highest centroid astigmatism error in both WTR and ATR eyes. This is the first study of its kind to be performed with the inclusion of both manual and laser cataract surgery patients.

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