Reproducibility of subfoveal choroidal thickness measurements with enhanced depth imaging by spectral-domain optical coherence tomography.
OBJECTIVE
To measure the interobserver reproducibility and intra-observer reproducibility of subfoveal choroidal thickness measurements performed by enhanced depth imaging of spectral-domain optical coherence tomography (EDI-OCT) in a population-based setting.


METHODS
The Beijing Eye Study 2011 was a population-based study performed in rural and urban regions of Greater Beijing. The study included 3468 individuals with a mean age of 64.6 ± 9.8 years (range, 50-93 years). The participants underwent EDI-OCT and the subfoveal choroidal thickness (SFCT) was measured. To examine the interobserver variability, all images were assessed by two examiners independently of each other within 2 months. To examine the intra-observer reproducibility, a smaller study sample consisting of 21 eyes of 21 healthy subjects from the Tongren Eye Center was included in the study. These latter subjects were scanned 10 times with 1 minute breaks between each examination. The SFCT was measured by the same observer within 2 weeks. The intrasession within subject SD, the coefficient of variation, and the intraclass correlation coefficient (ICC) were calculated.


RESULTS
EDI-OCTs were performed for 3233 subjects. Mean SFCT measured by grader one and grader two were 254.6 ± 107.3 μm and 253.8 ± 107.4 μm, respectively, with a mean difference of 3.14 ± 13.1 μm (95% confidence interval, 0.0, 24.0). Bland-Altman plot showed 1.9% (61/3233) points outside the 95% limits of agreement. For the assessment of the intra-observer reproducibility, the ICC was 1.00 (P < 0.001, and the mean coefficient of variation was 0.85% ± 1.48%).


CONCLUSIONS
Under routine examination conditions, SFCT measurements by EDI-OCT showed a high intra-observer reproducibility and interobserver reproducibility.
Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China.
Lei
L
Shao
Liang
L
Xu
Chang Xi
CX
Chen
Li Hong
LH
Yang
Kui Fang
KF
Du
Shuang
S
Wang
Jin Qiong
JQ
Zhou
Ya Xing
YX
Wang
Qi Sheng
QS
You
Jost B
JB
Jonas
Wen Bin
WB
Wei
D000368:Aged; D000369:Aged, 80 and over; D002829:Choroid / Q000033:anatomy & histology*; D003430:Cross-Sectional Studies; D005260:Female; D005584:Fovea Centralis; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D015203:Reproducibility of Results; D041623:Tomography, Optical Coherence / Q000379:methods*