Abstract
Purpose :
Information about the repeatability of measurements and agreement with validated devices is essential when a new instrument becomes commercially available. Precise biometric data are needed for numerous applications, including in myopia research, clinical myopia control, and IOL calculations. Here, the intersession repeatability of the MYAH US Optical biometer was investigated and agreement with the Lenstar was examined.
Methods :
Forty young adults (ages 25.2 ± 3.1 years, 20 male:20 female) presented for two lab visits, 2-4 days apart. Visits were scheduled within one hour of each other to minimize effects of diurnal variation. Visual acuity and non-cycloplegic autorefraction of the right eye were measured (WAM-5500). At visit 1, three measurements of the right eye were recorded with the MYAH US, then five measurements were recorded with the Lenstar. At visit 2, measurements were repeated with the MYAH US. The coefficient of variation (CoV) and intraclass correlation coefficient (ICC) were calculated for MYAH-measured axial length, corneal power, white-to-white diameter, and pupil size between sessions. Bland-Altman analysis was performed for MYAH- and Lenstar-measured axial length, white-to-white diameter, corneal power, and pupil size.
Results :
All participants had best corrected Snellen acuity of 20/20 or better. Spherical equivalent refraction of right eyes was -2.14 ± 2.21 D. Between visits, CoV and ICC for MYAH-measured parameters was 0.06% and >0.99 for axial length, 0.18% and >0.99 for corneal power, 0.57% and 0.96 for white-to-white diameter, and 7.0% and 0.76 for pupil diameter. Bland-Altman analysis showed that the mean ± limits of agreement between the MYAH and Lenstar were -0.01 ± 0.05 mm for axial length, 0.01 ± 0.17 D for corneal power, -0.14 ± 0.30 mm for white-to-white diameter, and 0.28 ± 1.06 mm for pupil size.
Conclusions :
For the MYAH US biometer, intersession repeatability for axial length, corneal power, white-to-white diameter, and pupil size was excellent. Additionally, measures were highly correlated between the MYAH and Lenstar biometers. Pupil size was most variable, due to the dynamic nature of this parameter.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.