Comparative analysis of optical biometers.

PURPOSE: To evaluate the level of agreement, repeatability, and correlation of 2 optical biometers, the IOLMaster (based on partial coherence interferometry [PCI]) and Aladdin (based on optical low-coherence interferometry [OLCI]) in terms of axial length (AL), mean keratometry (K), anterior chamber depth (ACD), and corneal diameter.

SETTING: Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom.

DESIGN: Prospective comparative case series.

METHODS: Each participant had biometry with both biometers. The level of agreement between the biometers was calculated using the Bland-Altman method. Double-angle polar plots were used to display the astigmatism vectors. Internal consistency was computed with the Cronbach α coefficient of reliability, whereas the dispersion of probability distribution was assessed with the coefficient of variation (CoV). The intraoperator repeatability was analyzed using the intraclass correlation coefficient (ICC); the AL was evaluated in all eyes and the mean K and the ACD in a subset of eyes.

RESULTS: The study comprised 215 eyes; the ICC for the mean K and ACD was calculated in a subset of 54 eyes. There was a statistically significant difference between the 2 biometers in all measurements (P < .05). The level of agreement was high with both methods. The ICC and internal consistency were excellent with both biometers; the CoVs were low.

CONCLUSIONS: The OLCI biometer provided good agreement and repeatability compared with the PCI biometer, the current gold standard in ocular biometry. Further comparative studies are necessary to clearly define the role of the OLCI biometer in predicting postoperative refractive outcomes.

FINANCIAL DISCLOSURES: Dr. Findl is a scientific advisor to Carl Zeiss Meditec AG. None of the other authors has a financial or proprietary interest in any material or method mentioned.