Macular Thickness Interoperator and Intraoperator Reproducibility in Healthy Eyes Using 7 Optical Coherence Tomography Instruments

PURPOSE: To evaluate macular thickness measurement reproducibility using 6 new spectral-domain (SD) optical coherence tomography (OCT) devices and 1 time-domain OCT device DESIGN: Prospective, observational study. METHODS: SETTING: Clinical practice. STUDY POPULATION: Macular thickness was assessed in 18 randomly chosen consecutive eyes of 18 healthy volunteers by 2 masked operators using 6 SD OCT devices and 1 time-domain OCT device. MAIN OUTCOME MEASURES: Intraoperator and interoperator reproducibility of OCT-measured central macular thickness. RESULTS: Mean macular thickness ranged from 172.77 to 272.87 mu m. Intraobserver Intraclass coefficient correlation ranged from 0.75 to 0.96. Intraobserver coefficient of variation ranged from 0.44 to 2.75. In Bland-Altman analysis, interoperator mean difference ranged from 0.22 to -9.69. An analysis of variance used for repeated measurement was statistically significant for instruments (P < .001) and operators (P = .04), but not for instruments x operators (P = .32). CONCLUSIONS: The 7 OCT devices presented differing macular thickness measurement values; the lowest value was with Copernicus, and the highest was with Spectralis HRA+OCT (Heidelberg Engineering). The new generation of SD OCT devices has good intraoperator reproducibility, but the Spectralis presents the highest reproducibility together with the best interoperator agreement. The software, and in particular the algorithm, used is the most important factor regarding reproducibility differences in macular thickness measurement. The main result of our study is that macular thickness absolute value differs for each device. For this reason, the devices are not interchangeable. (Am J Ophthalmol 2010;150:199-204. (C) 2010 by Elsevier Inc. All rights reserved.)