New mode for measuring axial length with an optical low-coherence reflectometer in eyes with dense cataract

PURPOSE: To evaluate a new algorithm for measuring eyes with dense cataract using a biometer based on optical low-coherence reflectometry (OLCR). SETTING: Shammas Eye Medical Center, Lynwood, California, USA, and Augenarztpraxis EYEC, Bern, Switzerland. DESIGN: Cross-sectional retrospective study. METHODS: Data were collected from 2 sites where the new Dense Cataract Measurement mode for the OLCR optical biometer (Lenstar LS 900) had been implemented. Related ultrasound (US) data for patients whose eyes could not be measured with optical biometry were also collected where available. The percentage of eyes that were measurable in the new mode that were not measurable in the standard mode was calculated. The quality of the measurements by the new mode was evaluated using postoperative axial length measurements and/or concurrent US measurements, where available. RESULTS: Data for 4791 eyes were available for analysis. Axial length measurement was possible using the standard algorithm in 94.4% of cases. The use of the new mode allowed for measurement of an additional 4.0% of cases, a statistically significant increase (P<.001). Comparisons of AL measurements with concurrent US or postoperative optical biometry showed high correlations, with the 95% limits of agreement of -0.47 to +0.29 mm, similar to results for standard measurements. CONCLUSIONS: The new measurement mode of the OLCR system provided a significant increase in the number of eyes that could be measured with optical biometry. Axial length measurements using the new mode appeared as reliable as those made using the standard measurement mode.