Initial Evaluation Of The New Ms39 Evo Axl Spectral-Domain Oct And Its Agreement With A Optical Low Coherence Interferometry Device

The aim of this study is to evaluate the agreement between the new MS39 biometer (CSO, Italy) and the Aladdin biometer (Topcon, Japan) in measuring axial length (AL, mm), mean keratometry (Kavg, D), anterior corneal astigmatism (ACA, D), anterior chamber depth (ACD, mm), lens thickness (LT, mm), white-to-white distance (WTW, mm), and central corneal thickness (CCT, µm).

This retrospective analysis included 91 eyes (right eye: 41, left eye: 50) from 91 patients. Measurements were obtained using both devices. The collected data were compared using Bland–Altman plot analysis (upper/lower limits of agreement [LoA]) and parametric and nonparametric statistical tests. Vector analysis was performed using a polar diagram to evaluate the difference vector of ACA measured by the two devices.

The mean and standard deviation for AL were 25.72±1.94 mm with MS39 and 25.70±1.93 mm with Aladdin (p=.94). The mean Kavg was 43.28±2.64 D with MS39 and 43.19±2.71 D with Aladdin (p = .53). The magnitude of ACA was 1.14±0.83 D with MS39 and 1.14±0.80D with Aladdin (p=.90). The ACD was 3.62±0.48 mm with MS39 and 3.61±0.53 mm with Aladdin (p=.78). The LT was 4.14±0.62 mm with MS39 and 3.91±0.44 mm with Aladdin (p=.059). The WTW was 11.87±0.43 mm with MS39 and 11.87±0.50 mm with Aladdin (p=.96). The CCT was 525 ± 51 µm with MS39 and 527 ± 51 µm with Aladdin (p = .03). The difference vector of ACA was 0.14 D at axis 49°.Bland–Altman analysis demonstrated a high level of agreement between the two devices, though bias was detected for LT and CCT.

The MS39 biometer and Aladdin biometer show a high level of agreement in the measurement of AL, K, ACA magnitude, ACD and WTW suggesting that they can be used interchangeably. However, measurements of LT and CCT showed discrepancies between the two devices, indicating they are not interchangeable for these parameters.