Agreement Between Swept-Source Optical Biometry and Scheimpflug-based Topography Measurements of Anterior Segment Parameters

Purpose: To estimate the agreement of anterior segment parameters between a swept-source optical biometry (IOLMaster 700; Carl Zeiss Meditec AG, Jena, Germany) and a Scheimpflug-based topography with high resolution (Pentacam HR; OCULUS, Wetzlar, Germany).

Design: Interinstrument reliability analysis.

Methods: A total of 62 eyes from 62 young adults were included in the study. Average keratometry (AveK) and simulated keratometry (SimK) along 2.0-mm-ring measurements provided by Pentacam HR, keratometry readings provided by IOLMaster 700, and central corneal thickness (CCT) and anterior chamber depth (ACD) values obtained from both devices were recorded. J0 and J45 vectoral components of astigmatism were obtained using power vector analysis. Mean keratometry (Km) values of IOLMaster 700 were compared for each type of Km value from Pentacam HR, while other parameters were compared between devices. To assess the agreement between measurements of the devices, Bland-Altman analysis was performed.

Results: The Pentacam HR exhibited significantly lower Km and CCT measurements (P < .001, for all); however, no significant difference emerged in J0, J45, and ACD measurements (P = .057, P = .574, and P = .64, respectively). The mean difference between AveK, SimK 2.0 mm, and the IOLMaster 700 Km was -0.20 diopter (D) and -0.14 D, respectively, while the mean difference between J0, J45, CCT, and ACD measurements was 0.07 D, -0.016 D, -5.05 μm, and 0.004 mm, respectively.

Conclusion: In clinical practice, Pentacam HR and IOLMaster 700 can be used interchangeably to measure J0 and J45 vectoral components of astigmatism for SimK 2.0 mm and IOLMaster keratometry values, as well as ACD and CCT measurements. However, SimK 2.0 mm and AveK values can be not interchangeable, as the devices have clinical and statistical differences in measurements.