Comparison Of Intraocular Lens Powers Calculated Using An Optical Low Coherence Interferometry Biometer (Lenstar®) And A Swept Source Oct Biometer (Anterion®)

Accurate biometry measurements and subsequent intraocular lens (IOL) power calculations are essential in cataract surgery. The primary purpose of this study was to investigate agreement in IOL power calculations between an Optical Low Coherence Interferometry Biometer (Lenstar®) and a Swept Source Optical Coherence Tomography Biometer (Anterion®). 

Tertiary National Health Service (NHS) Eye Hospital in London, United Kingdom.

Retrospective analysis was conducted. Data was collected between November 2021 and November 2022 and included all the measurements taken on Lenstar and Anterion Biometers. IOL power calculations for the closest lens choice to emmetropia were compared between biometers using SRK/T and HofferQ formulas. All analysis was conducted for the Hoya 250 IOL. Bland-Altman plots were used to assess agreement between IOL powers, axial length (AL) and keratometry measurements. 95% limits of agreement (LoA) were used to compare the two methods whereby 95% LoA is the mean difference ± 1.96SD of the difference. 

186 eyes from 124 patients (mean age 70.5 ± 12.5) were included. The same IOL power was selected by both biometers in 45.7% eyes using SRK/T. The absolute mean difference in IOL power selected was 0.54 ± 0.49D using SRK/T. The range of differences in IOL power was -2.5 to 5D. On review of the outliers, these patients had no specific comorbidities which made it more difficult to obtain accurate biometry. Comparison of AL and keratometry between the biometers showed a trend for shorter AL and flatter keratometry with Anterion, although this was not statistically significant.

It is important to evaluate the impact of changing biometer devices on IOL power selection for a given refractive outcome. Benchmark standards for NHS cataract surgery are that 85% of patients’ refractive outcomes are within +/-1D and 55% within +/-0.5D of the intended refraction. In our study, for the majority of eyes, IOL power selected for emmetropia was within +/-0.5D using both devices. Anterion had a tendency to select higher IOL powers, in approximately 1:3 patients.