Choroidal thickness ; Optical coherence tomography ; Reproducibility of results
Abstract
Purpose: To investigate the reproducibility of choroidal thickness measurements in healthy Koreans using two spectral domain optical coherence tomography (SD-OCT) instruments: Zeiss Cirrus HD-OCT (Carl Zeiss Meditec Inc., Dublin, CA, USA) and Heidelberg Spectralis (Heidelberg Engineering, Heidelberg, Germany).
Methods : Images were obtained in 60 eyes of 30 healthy undilated volunteers without ocular pathology in a clinical setting. The choroid was imaged in all subjects using Cirrus HD 1-line raster and Spectralis enhanced depth imaging (EDI). The choroid was measured subfoveally, 1500 µm temporal, and 1500 µm nasal to the fovea. All measurements were performed by two independent observers. One-way analysis of variance (ANOVA), Pearson correlation, and Bland-Altman analysis were used to compare measurements.
Results : The study group consisted of 15 males and 15 females. The mean age was 50.73 ± 15.09 years (range, 24-75 years). There was no significant difference in the mean choroidal thickness (p > 0.05) between systems for any location. The choroidal thickness measurements using two instruments (Cirrus vs. Spectralis) were also strongly correlated (p < 0.001).
Conclusions : In the present study of healthy Korean adults, good reproducibility was observed between choroidal thickness measurements of images obtained from Cirrus and Spectralis.