Abstract
Purpose :
Optical biometry, based on partial coherence interferometry, is the gold standard for for obtaining precise ocular measurements. The Carl Zeiss Meditec IOLMaster 700 utilizes a newer swept-source OCT technology to obtain all axial measurements, including axial length, anterior chamber depth, corneal thickness, and lens thickness. We evaluated the repeatability and reproducibility of the IOLMaster 700 and its agreement with the IOLMaster 500 and Lenstar LS900.
Methods :
Complete biometric measurements were taken on one eye chosen at random of 100 subjects, 51 of whom manifested cataracts (47 to 85 years, BCVA 20/16 to 20/80) and 49 of whom had clear lenses (22 to 58 years). Among the full cohort, there were 42 eyes with corneal astigmatism ≥ 0.75 D. Three sets of biometric measurements were taken by three operators with three different IOLMaster 700 units, and one operator took three measurements with the IOLMaster 500 and the Lenstar LS 900. A random effects model of analysis of variance (ANOVA) was used to estimate the repeatability and reproducibility. The 95% limits of agreement (95% LoA) were calculated for all comparisons using the first acceptable measurements from each instrument.
Results :
Comparing the IOLMaster 700 and IOLMaster 500 in cataract patients, 95% LoA were –0.01 to +0.06 mm for axial length, –0.44 to +0.27 D for mean corneal power, and –0.18 to +0.17 mm for anterior chamber depth. Likewise, a comparison between the IOLMaster 700 and the Lenstar LS 900 for corneal thickness and lens thickness yielded 95% LoA of –4 to +13 µm and –0.26 to +0.41 mm, respectively. The repeatability and reproducibility limits for the IOLMaster 700 in cataract patients were ±0.014 and ±0.023 mm for axial length; ±0.26 and ±0.27 D for mean corneal power; ±7 and ±11 µm for corneal thickness; ±0.02 and ±0.02 mm for anterior chamber depth; and ±0.02 and ±0.05 mm for lens thickness. For comparison, the repeatability limits in cataract patients were ±0.043 mm for axial length, ±0.24 D for mean corneal power, and ±0.15 mm for anterior chamber depth for the IOLMaster 500, and ±7 µm for corneal thickness and ±0.27 mm for lens thickness for the Lenstar.
Conclusions :
There was good agreement between the IOLMaster 700 and the comparative instruments and superior or equivalent precision. While some statistically significant differences were noted for axial length and mean corneal power, these would not be considered clinically meaningful.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.