Correlation Between Choroidal Thickness and Ciliary Artery Blood Flow Velocity in Normal Subjects

Abstract

To study the correlation between the choroidal thickness (CT) measured by spectral-domain optical coherence tomography (SD-OCT) and retrobulbar blood flow measured by color Doppler flowmetry (CD) in normal subjects. Healthy subjects underwent enhanced-depth imaging SD-OCT and CD using a linear 6 MHz to 18 MHz transducer. The maximal peak systolic velocity and resistance index (RI) were obtained for the ophthalmic artery (OA), short posterior ciliary artery (SPCA), and central retinal artery (CRA) and correlated with the subfoveal CT measured by SD-OCT. Twenty-seven eyes of 27 healthy patients were enrolled (mean age: 40.6 ± 12.4 years; range: 27-68 years). An inverse proportional relationship (P = .0496) was identified between the RI of the SPCA (mean, 0.6117 ± 0.07911) and the subfoveal CT (319.9 µm ± 83.79 µm) but not between the RI and the OA (mean: 0.7019 µm ± 0.07317 µm) or the CRA (mean: 0.68843 µm ± 0.08994 µm). The results of this study suggested there is an inverse proportional relationship between the RI of the SPCA and the subfoveal CT. The data also suggested a correlation between a decrease in the CT and increased RI in the retrobulbar arteries. Therefore, lower choroidal blood flow may explain the thinner CT in normal subjects.