Comparison of a New Optical Biometer That Combines Scheimpflug Imaging With Partial Coherence Interferometry With That of an Optical Biometer Based on Swept-Source Optical Coherence Tomography and Placido-Disk Topography.

Jinhai Huang,Shuangzhe Zhang,Qiaoyue Zhang,Ruixue Tu,Jinjin Yu,Giacomo Savini,Shihao Chen,Rui Ning,Yirang Wang,Xiaomin Huang

doi:10.3389/fmed.2021.814519

Abstract

PurposeTo evaluate measurement precision and to compare the Pentacam AXL (Oculus Optikgeräte, Wetzlar, German), a new optical biometer based on Scheimpflug imaging and partial coherence interferometry (PCI) with that of the OA-2000 biometer (Tomey, Nagoya, Japan), which combines swept-source optical coherence tomography (SS-OCT) and Placido-disk topography.MethodsAxial length (AL), central corneal thickness (CCT), anterior chamber depth (ACD), aqueous depth (AQD), mean keratometry (Km), astigmatism vectors J0, J45, and corneal diameter (CD) were measured in triplicate by two technical operators. Within-subject standard deviation (Sw), repeatability and reproducibility (2.77 Sw), coefficient of variation (CoV), and intraclass correlation coefficient (ICC) were used to assess the Pentacam AXL intra-observer repeatability and inter-observer reproducibility. Paired t-test and Bland-Altman plots were used to determine the agreement between the two biometers.ResultsThe new optical biometer had high intra-observer repeatability [all parameters evaluated had low CoV (<0.71%) and high ICC (>0.88)]. Inter-observer reproducibility was also excellent, with high ICC (>0.95) and low CoV (<0.52%). The 95% LoA between the new biometer and OA-2000 were insignificant for most of the parameters evaluated, especially for AL. However, the measurement agreement was moderate for CCT.ConclusionsIntra-observer repeatability and inter-observer reproducibility were excellent for all parameters evaluated using the new optical biometer based on Scheimpflug imaging and PCI. There was a high agreement between the two devices and hence could be clinically interchangeable for the measurement of most ocular parameters.

Highlights

Accurate measurements of ocular biometric parameters are crucial for both intraocular lens (IOL) power calculation and refractive surgery [1,2,3]
The new optical biometer had high intra-observer repeatability [all parameters evaluated had low coefficient of variation (CoV) (0.88)]
Intra-observer repeatability and inter-observer reproducibility were excellent for all parameters evaluated using the new optical biometer based on Ocular Biometry of Pentacam AXL vs. OA-2000

Summary

Introduction

Accurate measurements of ocular biometric parameters are crucial for both intraocular lens (IOL) power calculation and refractive surgery [1,2,3]. A new optical biometer (Pentacam AXL, Oculus, Germany), which combines Scheimpflug imaging and partial coherence interferometry (PCI) has been introduced into the market. The Pentacam (without PCI) has been widely used in ophthalmology, the measurement accuracy of the new optical biometer has yet to be determined. Recent studies have demonstrated that the OA-2000 (Tomey, Japan), an optical biometer that combines swept-source optical coherence tomography (SS-OCT) with Placido disc topography, offers good repeatability and reproducibility for measuring biometrical parameters. OA-2000 has been demonstrated to have a high agreement with other biometers in the market for most of the ocular parameters evaluated [7, 8]. Our initial aim of this study was to prospectively evaluate the intraobserver repeatability and inter-observer reproducibility of the measurements obtained using the Pentacam AXL. Our second aim was to compare the measurement agreement between these two optical biometers

Methods

Results

Conclusion