# Repeatability of Pentacam-derived intraocular lens decentration measurements and the level of agreement with OPD-Scan III: A prospective observational case series

## TL;DR

This study shows that the Pentacam device provides repeatable measurements of intraocular lens decentration, but results differ significantly from those of the OPD-Scan III device.

## Contribution

The study evaluates the repeatability of Pentacam IOL decentration measurements and compares them with OPD-Scan III for the first time.

## Key findings

- Pentacam measurements showed high repeatability with ICC values ranging from 0.76 to 0.89.
- Bland-Altman analysis revealed wide 95% limits of agreement between Pentacam and OPD-Scan III.
- No significant differences were found among three consecutive Pentacam measurements.

## Abstract

This study aimed to assess the repeatability of intraocular lens (IOL) decentration measurements obtained through Pentacam, based on corneal topographic axis (CTA) and pupillary axis (PA), and to evaluate the level of agreement between Pentacam and OPD-Scan III devices in measuring IOL decentration.

In this prospective observational case series, three measurements were performed with Pentacam to evaluate the repeatability of the measurements. The analysis included the calculation of the mean and standard deviations (SD), conducting a repeated measures analysis of variance (rANOVA), and determining an intraclass correlation coefficient (ICC) to assess the repeatability of the measurements. Moreover, Bland-Altman analysis was employed to assess the agreement between Pentacam and OPD-Scan III devices in measuring IOL decentration. IOL decentration measurements were obtained with respect to both CTA and PA.

A total of 40 eyes from 40 patients were analyzed. The rANOVA revealed no significant difference among three consecutive measurements of IOL decentration obtained with Pentacam. The mean SD of all parameters ranged from 0.04 mm to 0.07 mm. With CTA as the reference axis, the ICC values for Pentacam measurements of IOL decentration were 0.82 mm for the X-axis, 0.76 mm for the Y-axis, and 0.82 mm for spatial distance. When using PA as the reference axis, the corresponding ICC values were 0.87, 0.89, and 0.77, respectively. The 95% limits of agreement for all IOL decentration measurements were wide when comparing Pentacam and OPD-Scan III.

Pentacam demonstrated high repeatability in measuring IOL decentration with respect to both CTA and PA. However, due to poor agreement between Pentacam and OPD-Scan III measurements, caution should be exercised when using data interchangeably between the two devices.