ABSTRACT
ObjectiveTo assess the repeatability （intra-operator variability） and reproducibility （inter-operator variability） of a new partial coherence interferometry （PCI）-based ocular biometer， Myopia Master， and its agreement with IOL Master 500 for measuring axial length （AL） and corneal curvature （K） in children aged 8-12 years. MethodsThe same operator measured school children with the Myopia Master and the IOL Master 500 in random order to assess agreement. Additionally， some of these children received measurements from another operator using the Myopia Master to assess repeatability and reproducibility. AL， flat keratometry （Kf）， steep keratometry （Ks）， mean keratometry （Km）， J0 and J45 were analyzed. The repeatability and reproducibility were assessed by the within-subject standard deviation （Sw）， test-retest repeatability （TRT）， coefficient of variation （CoV） and intra-class correlation coefficient （ICC）. The agreement between the Myopia Master and the IOL Master 500 was assessed by Bland-Altman plots and 95% limits of agreement （LoA）. ResultsBoth repeatability and reproducibility of the Myopia Master were high for AL measurements （Sw=0.02 mm， ICC=0.999； Sw=0.04 mm， ICC=0.998）， but moderate for K measurements （Sw range， 0.04 to 0.12 D， ICC range， 0.861 to 0.991； Sw range， 0.06 to 0.20 D， ICC range， 0.835 to 0.992）. There were significant mean differences between the Myopia Master and the IOL Master 500 in measurements of AL （-0.01±0.04） mm， Kf （-0.09 ± 0.15） D， Ks （-0.47±0.40） D， and Km （-0.28±0.23） D， J0 （0.18±0.20） D and J45 （-0.01±0.12） D. ConclusionsThe Myopia Master provided high repeatability and reproducibility for AL measurements in schoolchildren with myopia， but the Myopia Master and the IOL Master 500 cannot be used interchangeably in measuring AL and K.
ABSTRACT
AIM:To evaluate the correlation between axial lengths and anterior segment parameters using swept-source optical coherence tomography(SS-OCT).METHODS:For the cross-sectional clinical study, a total of 109 adult volunteers with different degrees of myopia recruited from January 1, 2022, to March 31, 2022, at the ophthalmology clinic of the First Affiliated Hospital of Zhengzhou University were included. Participants were divided into 4 groups based on axial length(AL): group A(AL≤24.0mm), group B(24.0mm<AL≤25.0mm), group C(25.0mm<AL≤26.0mm)and group D(AL>26.0mm). Anterior segment examinations were performed using SS-OCT, including: central corneal thickness(CCT), lens thickness(LT), anterior chamber depth(ACD), anterior chamber width(ACW), angle opening distance(AOD500), angle recess area(ARA500), trabecular iris space area(TISA500), trabecular iris angle(TIA500), crystalline lens rise(CLR). The relationships between these data and AL, spherical equivalent(SE)were analyzed.RESULTS:There was no difference in the comparison of CCT among the four groups(P>0.05). There were differences in SE, LT, ACD, ACW, AOD500, ARA500, TISA500, TIA500 and CLR among the four groups(all P<0.01). SE and LT were negatively correlated with AL(r=-0.75, -0.41, all P<0.01); ACD, ACW and CLR were positively correlated with AL(r=0.58, 0.45, 0.54, all P<0.01); AOD500, ARA500, TISA500 and TIA500(temporal and nasal side)were positively correlated with AL(all P<0.01). ACD and CLR were negatively correlated with SE(r=-0.21,-0.25, all P<0.01), and LT was positively correlated with SE(r=0.21, P<0.05).CONCLUSION:As AL increases, CCT remains unchanged while the ACD and ACW increase. The position of the crystalline lens moves backward and LT decreases.