Clinical Publications

MYAH

Precision and agreement of axial length in paediatric population measured with MYAH and AL-Scan biometers

AUTHORS:

Aldaba, M., Ochando, P., Vila-Vidal, N., Vinuela-Navarro, V., Guisasola, L., & Perez-Corral, J.

PUBLICATION:

Clin Exp Optom. 2024 Sep;107(7):748-753. doi: 10.1080/08164622.2023.2277287. Epub 2023 Nov 13.

Study Purpose

To assess the precision (repeatability and reproducibility) and agreement of the MYAH and AL-Scan biometers in a paediatric population

Overview

Study Design

Prospective study

# of Eyes/
Patients

Right eyes of 187 subjects; mean age was 8.5 ± 0.3 years, ranging from 7.9 to 9.8 years

Study Device

MYAH (Topcon, Japan)
AL-Scan (Nidek, Japan)

Outcome Measures

Repeatability and reproducibility of mean axial length measurements and agreement of the 2 devices

Results

For the repeatability study, the within-subject standard deviation was 0.01 mm, and the repeatability limit was 0.04 mm for both instruments, with no statistically significant differences among repeated measures (p = 0.162 for MYAH and p = 0.774 for AL-Scan)
For the reproducibility study, the within-subject standard deviation was 0.01 mm and the repeatability limit was 0.04 mm. There were statistically significant differences for the repeated measures for the AL Scan (p = 0.002) but not for the MYAH (p = 0.643)
For the agreement study between both instruments, the 95% limit of agreement ranged from −0.04 to 0.05 mm, and the differences were statistically significant (p = 0.021). The comparison has a LoA of approximately ±0.04 mm, and thus the difference among instruments was less than this value in 95% of the cases

IMOvifa reduced measurement time by

39%

FIGURE 1

FIGURE 1.

Bland and Altman plot for the agreement study between MYAH and AL-Scan. The difference between measurements (MYAH minus AL-Scan) is plotted against the mean value of both measurements. The dash-dotted line indicates the mean difference and the dashed lines the upper and lower LoA. Adapted from Clin Exp Optom. 2024 Sep;107(7):748- 753. doi: 10.1080/08164622.2023.2277287. Epub 2023 Nov 13.

Conclusions

• In the analysis of the precision of the MYAH and AL-Scan in paediatric population, the repeatability and reproducibility have been found to be equal • The good agreement between instruments suggests that the two devices can be used interchangeably for myopia control