# Clinical Comparative Evaluation of Two New-Generation Optical Biometers: Intrasession Repeatability and Agreement of Biometric Parameters

## TL;DR

This study compares two optical biometers for eye measurements and finds that the HBM-1 is highly repeatable and agrees well with the IOLMaster 700.

## Contribution

The study provides a clinical evaluation of the HBM-1 optical biometer's repeatability and agreement with the IOLMaster 700 across a broad age range.

## Key findings

- The HBM-1 showed excellent intrasession repeatability with ICC ≥ 0.97 for most biometric parameters.
- The HBM-1 and IOLMaster 700 had small mean biases for axial length, anterior chamber depth, and lens thickness.
- Age was not significantly associated with discrepancies in axial length measurements.

## Abstract

Objectives: This study aims to evaluate the intrasession repeatability of the HBM-1 (Huvitz) optical biometer and to assess its agreement with the IOLMaster 700 (Zeiss) for the main biometric parameters used in intraocular lens (IOL) power calculation and in myopia management. Methods: A cross-sectional observational study was conducted in 82 eyes of 82 patients with the following age distribution: pediatric 26.8%, young adults 35.4%, and older adults 37.8% (total range 6–79 years). Optical biometry was performed three consecutive times with both biometers in the same session by a single trained examiner. HBM-1 repeatability was assessed using the within-subject standard deviation (Sw), the repeatability coefficient, and the intraclass correlation coefficient (ICC). Agreement between biometers was analyzed using Bland–Altman plots (limits of agreement, LoA). Results: The HBM-1 showed excellent intrasession repeatability, with very low Sw values—on the order of hundredths of a millimeter for axial length (AL), anterior chamber depth (ACD), and lens thickness (LT), and hundredths of a diopter for keratometry—with ICC ≥ 0.97 for most parameters. The mean bias (HBM-1 vs. IOLMaster 700) was small: AL 0.012 ± 0.052 mm (p = 0.045; LoA: −0.09 to 0.11 mm), ACD 0.059 ± 0.068 mm (p < 0.001; −0.07 to 0.19 mm), LT 0.052 ± 0.090 mm (p < 0.001; −0.12 to 0.23 mm), and central corneal thickness 0.82 ± 7.12 μm (p = 0.301; −13.1 to 14.8 μm). For corneal diameter and corneal curvature, mean differences were small (≤0.07 D) and not statistically significant in most cases. Age was not associated with discrepancies in AL but showed weak correlations with some anterior segment differences, without clear clinical relevance. Conclusions: The HBM-1 demonstrated excellent intrasession repeatability and a good level of clinical agreement with the IOLMaster 700 in a broad population that included children, young adults, and older adults.