Abstract / Summary
Conventional optical coherence tomography (OCT) enables detailed assessment of retinal thickness, whereas enhanced depth imaging OCT (EDI-OCT) improves visualization of the choroid and enables measurement of choroidal thickness. B-scan ultrasonography (B-scan USG) provides complementary imaging of the posterior ocular wall, although its thickness measurements may differ from those obtained using EDI-OCT. Choroidal thickness varies with physiological factors, including age, circadian rhythms, pregnancy, and physical activity. This study aimed to compare retinochoroidal complex thickness measurements obtained using EDI-OCT and B-scan USG and to assess their correlation and agreement in healthy adults. To compare retinochoroidal thickness measurements obtained using both techniques; a prospective, observational, analytical, cross-sectional study was conducted on 50 eyes of healthy subjects over the age of 18 years old. After applying selection criteria, 41 eyes were included for statistical analysis. Retinochoroidal complex thickness was measured using both techniques in one eye per participant, who attended the Ophthalmology Service in a tertiary care hospital. Data distribution was assessed using the Shapiro-Wilk test. Comparisons were performed using the Wilcoxon signed-rank test, correlations using Spearman's rho, and agreement using Bland–Altman analysis. Measurements obtained via B-scan USG were significantly higher than those recorded by EDI-OCT (1446.83 ± 180.50 µm vs. 595.24 ± 57.18 µm; Z = −5.579; p < 0.001). A weak but statistically significant positive correlation was observed between the two methods (rho = 0.336; p = 0.032). Bland–Altman analysis showed a mean bias of 851.6 µm, with 95% limits of agreement between 485.0 and 1218.1 µm, as well as a progressive proportional error as the mean of the measurements increased. No significant differences were found based on sex, eye laterality, or age. In healthy adults, B-scan USG and EDI-OCT measurements of retinochoroidal complex thickness showed limited agreement and were not interchangeable. EDI-OCT should be used for quantitative assessment, while B-scan USG may provide complementary structural information when optical imaging is unavailable or limited.