Factors Affecting Choroidal Vascular Density in Normal Eyes: Quantification Using En Face Swept-Source Optical Coherence Tomography

Purpose To quantify the vascular density of the choroid of normal eyes and to identify the influencing factors using en face images obtained with swept-source optical coherence tomography (SS OCT). Design Prospective cross-sectional study. Methods One hundred and sixty-three eyes of 163 healthy volunteers (83 female; mean age 42.2 ± 22.6 years) with a corrected visual acuity of ≥1.0 were investigated. En face SS OCT images of the choroid were used for quantitative assessment of the vascular density in the large choroid vessel layer. Relationships between vascular density of the choroid and age, sex, refractive error (RE), axial length (AL), and subfoveal choroidal thickness (SCT) were also investigated. Results There was a significant negative relationship between vascular density of the choroid and subject age (P <.001). Analysis according to age showed a significant correlation in the group aged >30 years (P <.001), but not in the group aged ≤30 years (P =.225). SCT had a significant positive relationship with vascular density of the choroid (P <.001). However, a significant correlation was not observed between sex, RE, or AL and vascular density of the choroid (P =.981, P =.292, and P =.216, respectively). Multivariable regression analysis with vascular density of the choroid as the dependent variable and age, sex, RE, AL, and SCT as independent variables showed that age and SCT are important determinants of vascular density of the choroid (P <.001). Conclusion Age and SCT affect vascular density of the choroid.