Normal aging changes in the choroidal angioarchitecture of the macula.

The choroidal vascularity index (CVI) has been shown to be sensitive in detecting changes in choroidal angioarchitecture in a range of ocular diseases. However, changes in CVI in association with normal physiological aging and spatial distribution remains to be determined. This is significant as a range of ocular conditions with choroidal degeneration are associated with aging. In this study, we assessed CVI for 106 healthy eyes from 106 individuals (range 21-78 years old, ~ 20 individuals/decade) at 15 eccentricities across the macula (0, 230 µm, 460 µm, 690 µm, 1,150 µm, 1,380 µm and 2,760 µm from the fovea in the superior and inferior direction). Total choroidal area, luminal area and stromal area were all significantly decreased with age (p < 0.001 for all parameters). CVI was also significantly decreased with age (p < 0.01) and eccentricity. Fitting of quadratic regression curves to CVI as a function of age yielded a good fit for all eccentricities (r2 = 0.55-0.80) and suggested a decrease in CVI from the ages of 33-43 years at a rate of 0.7-2.7% per decade. CVI was lower in the inferior versus superior retina at matching eccentricities and a significant difference in age-related decline of CVI with eccentricity only occurred in inferior locations. These findings suggest choroidal angioarchitecture declines from the 4th decade of life with potential eccentricity differences in the inferior and superior retina. Considering the number of age-related diseases with choroidal dysfunction, these results provide foundational knowledge to understand choroidal involvement in these diseases.