Magnetic resonance Imaging vs. ultrasound biometry in the equatorial plane in human eyes

Abstract

Abstract Purpose Our purpose was to assess the reliability of ultrasound (US) measurements versus magnetic resonance imaging (MRI) in the equatorial plane in human eyes. Methods Four patients who later underwent retinal prosthesis implantation and 8 healthy volunteers aged between 20 and 50 years of age (mean (SD) age 36.8 (8.0) years) were included in the study. One operator measured the axial length and the vertical equatorial diameter (in maximal down gaze) with US applying a contact 10 MHz A‐scan transducer. MR measurements (Siemens MAGNETOM Trio, A Tim System) were taken using five different sequences. MRI and US data were compared with paired sample t‐test and Pearson correlation analysis. The intraclass correlation coefficient (ICC) was calculated. Results Axial diameter (mean ±SD) was measured by US (24.45 ±1.00 mm), and by MRI (24.22 ±1.08). Vertical diameter was also measured by US (24.12 ±1.10) and by MRI (24.22 ±1.01 respectively). No significant difference was found between US and MRI data in axial and vertical planes (p=0.134, 0.598 respectively). Significant correlation could be found both in axial (p=0.01, r=0.933) and in the vertical planes (p=0.02, 0.831). Intraclass correlation coefficient (ICC) revealed good reliability with high consistency (axial: 0.963, vertical: 0.906) and absolute agreement values (axial: 0.955, vertical: 0.912). Conclusion Our results demonstrated that both the US and the MRI can be used to assess the equatorial diameter of the human eyeball. US measurements revealed high correlation with MRI data with respect to the equatorial plane and axial length.