Comparisons of Choroidal Thickness of Normal Eyes Obtained by Two Different Spectral-Domain OCT Instruments and One Swept-Source OCT Instrument

RESULTS. We studied 35 subjects. The intrarater correlation coefficient (95% confidence interval) was 0.994 (0.988–0.994) for Spectralis-SD-OCT, 0.996 (0.993–0.998) for Topcon-SDOCT, and 0.997 (0.991–0.998) for DRI-SS-OCT (P < 0.001). The interrater correlation coefficient was 0.995 (0.991–0.998) for Spectralis-SD-OCT, 0.995 (0.990–0.998) for TopconSD-OCT, and 0.996 (0.992–0.998) for DRI-SS-OCT (P < 0.001). The average SFCT was 273.2 lm with Spectralis-SD-OCT, 269.1 lm with the Topcon-SD-OCT, and 280.5 lm with DRI-SSOCT. The intermachine correlation coefficient was 0.982 (0.964–0.991) for Spectralis-SD-OCT versus Topcon-SD-OCT, 0.907 (0.815–0.953) for Topcon-SD-OCT versus DRI-SS-OCT, and 0.911 (0.832–0.954) for DRI-SS-OCT versus Spectralis-SD-OCT (P < 0.001). The SFCT measured with DRI-SS-OCT was significantly thicker than that with Topcon-SD-OCT, with a mean difference of 11.41 6 30.27 l m( P ¼ 0.032). CONCLUSIONS. In normal adult eyes, there was good reproducibility and repeatability of SFCT measurements obtained by the SD-OCT and SS-OCT instruments. However, the choroid measured with DRI-SS-OCT was thicker than that measured with both SD-OCT instruments, and, thus, the choroidal thickness should not be compared between the SD-OCT and SSOCT instruments. (www.umin.ac.jp/ctr number, UMIN000011259.)