Reproducibility of Choroidal Thickness Measurements Across Three Spectral Domain Optical Coherence Tomography Systems

Purpose: To investigate the reproducibility of choroidal thickness measurements in normal subjects on 3 spectral domain optical coherence tomography (SD-OCT) instruments: Zeiss Cirrus HD-OCT (Carl Zeiss Meditec Inc., Dublin, CA), Heidelberg Spectralis (Heidelberg Engineering, Heidelberg, Germany), and Optovue RTVue (Optovue Inc., Fremont, CA). Design: Cross-sectional non-interventional study. Participants: Images were obtained in 28 eyes of 28 healthy undilated volunteers without ocular pathology in a clinical setting. Methods: All subjects were imaged on the fovea using Cirrus HD 1-line raster, Spectralis enhanced depth imaging (EDI), and RTVue retina-cross. Main Outcome Measures: The choroid was measured subfoveally, 750 mu m temporal, and 750 mu m nasal to the fovea. All measurements were performed by 2 independent observers. Two-way analysis of variance (ANOVA) with Bonferroni's post-test, Pearson correlation, and Bland-Altman analysis were used to compare measurements. Results: The group of 28 subjects consisted of 7 men and 21 women, with an average age of 35.2 years (range, 23-64 years). A 2-way ANOVA with Bonferroni's post-test revealed no significant difference in the average subfoveal choroidal thickness (P > 0.05) among systems for any location: subfoveally, 750 mu m temporal, and 750 mu m nasal to the fovea. The measurements of choroidal thickness from any pair of 3 instruments (Cirrus vs. Spectralis, Cirrus vs. RTVue, Spectralis vs. RTVue) were also strongly correlated. The Pearson correlation among all 2 system pairs of the 3 systems was greater than 0.9 (P < 0.0001). The 95% limits of agreement among 4 choroidal thickness measurements were +11.21% to -13.57% (bias -1.17) between Cirrus and RTVue, +10.85% to -12.45% (bias -0.80) between Spectralis and RTVue, and +12.81% to -13.33% (bias -0.25) between Cirrus and Spectralis. Conclusions: In our population of young healthy adults with normal vision, there was good reproducibility among choroidal thickness measurements of images acquired with Cirrus, Spectralis, and RTVue. Financial Disclosure(s): Proprietary or commercial disclosure may be found after the references. Ophthalmology 2012; 119: 119-123 (C) 2012 by the American Academy of Ophthalmology.