Comparison axial length measurements from three biometric instruments in high myopia

Area of Science:

• Ophthalmology
• Biomedical Optics
• Medical Devices

Background:

• Accurate axial length (AL) measurement is crucial for intraocular lens (IOL) power calculation.
• High myopia presents unique challenges for AL measurement accuracy.
• Comparing different biometry devices is essential for clinical practice.

Purpose of the Study:

• To compare axial length measurements using Lenstar, IOLMaster, and A-scan ultrasound in normal and high myopia.
• To assess the repeatability and agreement of these devices for AL measurement.
• To evaluate the impact of measurement differences on IOL power calculations.

Main Methods:

• Inclusion of 84 normal eyes and 49 high myopia eyes.
• Sequential AL measurements using Lenstar, IOLMaster, and ultrasound.
• Assessment of measurement repeatability using pooled coefficients of variation (CVs).
• Inter-device agreement evaluated with Bland-Altman analyses and paired t-tests.

Main Results:

• All three devices demonstrated excellent intra-visit repeatability for AL measurements in both groups.
• Lenstar and IOLMaster showed slightly higher AL values than ultrasound (P<0.001).
• No significant difference in IOL power calculation between Lenstar and IOLMaster was found.

Conclusions:

• Lenstar, IOLMaster, and ultrasound exhibit excellent repeatability for axial length measurements.
• Clinicians should be aware of the systematic differences in AL and IOL power between partial coherence interferometry devices and ultrasound.