Evaluation Of Refractive Error Measurements Of The Pentacam Axl Wave And The Itrace Aberrometer In Relation To Subjective Refraction

Published 2022 - 40th Congress of the ESCRS

Reference: PP03.17 | Type: Free paper | DOI: 10.82333/jq49-s030

Authors: Mehdi Shajari* ¹ , Roxana Assadnazari ¹ , Wolfgang Mayer ² , Christoph Lwowski ¹ , Anna Schuh ² , Thomas Kohnen ¹

¹University Hospital Frankfurt,Frankfurt,Germany, ²University hospital Munich,Munich,Germany

Purpose

To evaluate the autorefraction function of the iTrace (Tracey Technologies) and Pentacam AXL Wave (Oculus) devices in terms of measurement accuracy and reproducibility in comparison to subjective refraction as well as to each other.

Setting

Department of Ophthalmology, Goethe-University, Frankfurt am Main, Germany

Methods

The values of the sphere, cylinder and axis were obtained by subjective refraction (SR), Pentacam AXL Wave, and Tracey Visual Function Analyzer (VFA, iTrace model). The measurements were performed on 60 eyes of 60 untreated, phakic subjects. These examinations were carried out by one examiner on the same eyes, first under non-cycloplegic and then under cycloplegic conditions. The agreement of the devices with the subjective refraction as well as the interinstrument agreement were analysed using 95% limits of agreement (95% LoA). Vector analysis was used to assess the astigmatism. Furthermore, the intratest repeatability was calculated based on 2 standard deviations (SDs) and intraclass correlation coefficients (ICCs).

Results

Mean differences between SR and Pentacam AXL Wave for SE, sphere, and cylinder were 0.23 D, 0.26 D, and -0.07 D, respectively, and between SR and iTrace 0.13 D, 0.22 D, and -0.19 D, respectively. For Pentacam AXL Wave the 95% LoA for SE, sphere, and cylinder ranged from -0.4 to 0.86 D, -0.39 to 0.91 D and -0.37 to 0.24 D, respectively, and from -0.52 to 0.77 D, -0.49 to 0.94 D and -0.64 to 0.25 D, respectively, for iTrace. Vector analysis showed the mean difference of 0.01 D X 109° ± 0.20 D between SR and Pentacam, and of 0.12 D X 77° ± 0.32 D between SR and iTrace. Pentacam AXL Wave’s 2 SDs were 0.27 D for SE, 0.29 D for sphere, and 0.13 D for cylinder, and iTrace results were 0.33 D, 0.35 D and 0.22 D, respectively.

Conclusions

Both Pentacam AXL Wave and iTrace showed reliable and reproducible refractive measurement results that are comparable to those of subjective refraction.