Correlation between cross-sectional shape of choroidal veins and choroidal thickness

Purpose: To determine whether a significant correlation exists between the ratio of the vertical and horizontal diameters of the choroidal veins and the choroidal thickness in normal eyes. Methods: Six clinic-based normal eyes were studied. The macula and retina around the optic disc were examined by spectral-domain optical coherence tomography (OCT) during indocyanine green angiography (IA), and choroidal thickness maps were constructed. The vertical and horizontal diameters of the choroidal veins in the OCT images and horizontal diameters in the IA images in the venous phase were measured at 12 locations of different choroidal thickness. The horizontal diameter of the choroidal veins measured in the OCT images and the corresponding IA images were compared, and the correlation between the ratio of the vertical and horizontal diameters of the choroidal veins and the corresponding choroidal thickness was determined. Results: The horizontal diameters of the choroidal veins measured in IA and OCT images were not significantly different and were significantly correlated (r = 0.73; P < 0.01). The ratio of the vertical and horizontal diameters of the choroidal veins was significantly correlated with the choroidal thickness (r = 0.85; P < 0.001). Conclusion: The significant correlation between the ratio of the vertical and horizontal diameters of the veins to the choroidal thickness should be considered when the cross-sectional area of the choroidal veins is evaluated.