Comparison of 2 modern swept-source optical biometers—IOLMaster 700 and Anterion

Abstract

Purpose To compare biometric measures from 2 modern swept-source OCT biometers (IOLMaster700 (Z, Carl-Zeiss-Meditec) and Anterion (H, Heidelberg Engineering)) and evaluate the effect of measurement differences on the resulting lens power (IOLP). Methods Biometric measurements were made on a large study population with both instruments. We compared axial length (AL), central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness (LT) and corneal front and back surface curvature measurements. Corneal curvature was converted to power vectors and total power derived using the Gullstrand formula. A paraxial lens power calculation formula and a prediction for the IOL axial position according to the Castrop formula were used to estimate differences in IOLP targeting for emmetropia. Results There were no systematic differences between measurements of AL (− 0.0146 ± 0.0286 mm) and LT (0.0383 ± 0.0595 mm), whereas CCT yielded lower (7.8 ± 6.6 µm) and ACD higher (0.1200 ± 0.0531 mm) values with H. With H, CCT was lower for thicker corneas. The mean corneal front surface radius did not differ (− 0.4 ± 41.6 µm), but the corneal back surface yielded a steeper radius (− 397.0 ± 74.6 µm) with H, giving lower mean total power (− 0.3469 ± 0.2689 dpt). The astigmatic vector components in 0°/90° and 45°/135° were the same between both instruments for the front/back surface or total power. Conclusion The biometric measures used in standard formulae (AL, corneal front surface curvature/power) are consistent between instruments. However, modern formulae involving ACD, CCT or corneal back surface curvature may yield differences in IOLP, and therefore, formula constant optimisation customised to the biometer type is required.

Influence and predictive value of optional parameters in new-generation intraocular lens formulas

“…Both devices are reported to have systematic differences in PR. 28 It is not surprising that the results of PR data for a thick lens cornea model rely on the validity/quality of the input data. It is likely that differences between formula variations of the Kane, EVO 2.0, RBF, and PEARL-DGS formulas are less drastic after constant optimization, but this can not be proven in this study due to the unpublished/undisclosed nature of these formulas preventing us from optimizing these formulas.…”

Astigmatism Management in Modern Cataract Surgery

“…Swept-source optical coherence tomography (SS-OCT) is also a newer generation technology capable of measuring both the corneal front curvature and the back curvatures, in addition to intraocular distances and lens thickness [ 23 ]. The IOLMaster 700 (Carl Zeiss, Oberkochen, Germany) and the Argos (Movu, a Santec Company, Santa Clara, CA, USA) are two common SS-OCT biometers.…”

Prediction of corneal power vectors after cataract surgery with toric lens implantation–A vector analysis

“…However, our study has several limitations: First, our data are based on a single measurement made preoperatively with the IOLMaster and pre-and postoperatively with the Casia2. Variations in the results due to multiple measurements [5][6][7][8] have not been considered in our prediction models. Second, the study population is relatively small with N = 88 eyes, and therefore a refinement of this prediction algorithm with a larger population is recommended.…”

“…In most cases tIOLs are calculated based on measurement data of the corneal front surface as derived from a manual keratometer, automated keratometer integrated in a biometer, or a corneal topographer. Even where corneal back surface data are available from a Scheimpflug [4] or optical coherence tomographer [5][6][7], many calculation schemes for tIOLs use keratometric data. However, it is well known in ophthalmology that a keratometer or the simulated keratometry SimK of a topographer does not fully describe the corneal power [8][9][10].…”