Feasibility and repeatability of ocular biometry measured with IOLMaster 700 in a large population-based study

Purpose: To evaluate the feasibility and repeatability of IOLMaster 700 biometry measurements in an adult population. Furthermore, to assess the value of the Quality Indicators (QIs) provided by the device. Method: As part of the large population-based Leipzig Research Centre for Civilization Diseases (LIFE) Adult-Study, randomly selected participants from Leipzig, Germany were evaluated with the ZEISS IOLMaster 700. Age range was 26-85 years, with 53% of participants above 70 years of age. Axial length (AL), central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness (LT) and keratometry (K) were assessed in 1767 right eyes. Measurements were repeated twice and in a subset of 1331 eyes, three times. Measurement feasibility was evaluated for three levels; successful, with warnings and failed, using the inbuilt QIs. Repeatability was assessed as within-subject standard deviation (SD) and repeatability limits were calculated. Results: First measurement success rate for phakic eyes was over 99% for AL, CCT, ACD, over 98% for LT and over 97% for K. K had 16% eyes with warnings and the recommendation to repeat the measurement. Excluding the measurements with warnings resulted in a reduction of mean SD for AL from 48 to 4 mu m and for mean K from 0.08 to 0.04 D. Repeatability for phakic eyes was 8 mu m for AL, CCT, ACD and LT and 2.3 mu m for CCT; 0.07 D and 0.12 D for mean K and delta K, respectively, for phakic cases without warnings (two measurements). Conclusions: In our population-based sample, the IOLMaster 700 collected data for AL, CCT, ACD, LT and K from the vast majority of eyes. Considering the built-in QIs improved the measurement variability substantially. Repeatability measurements indicate that clinically meaningful changes can be detected reliably with this instrument.