Fig 1.
Choroidal thickness measurement.
The cross-sectional image of choroid was obtained in Enhanced Depth Imaging (EDI) scan of Optical Coherence Tomography. The horizontal scan line is centered on fovea. The outer border of RPE and the outer border of choroid were bounded by two lines. The choroidal thickness was measured as the distance between the two boundary lines. Five locations with 1mm interval (T2,T1,SF,N1,N2)were measured. The sample image was from the right eye of a ten-year-old boy with -3.0D refractive error. T2 = 2mm temporal to fovea, T1 = 1mm temporal to fovea, SF = subfovea, N1 = 1mm nasal to fovea, N2 = 2mm nasal to fovea.
Table 1.
Choroidal Thickness (CT) of each measurement location.
Fig 2.
Linear regression analysis of axial length and refractive error.
Refractive error showed significantly negative correlation with axial length (R2 = 0.5616, F = 128.023 p = 0.000), linear equation: y = -0.472x + 23.382.
Table 2.
Correlation analysis between choroidal thickness of each point and Refractive Error (RE), Axial Length(AL) and age.
Table 3.
Multiple regression of CT(sf and n1) with age and AL.
Fig 3.
The scatter plot graphs showing significant correlation between Choroidal Thickness(CT) of N1 and three factors (refractive error, axial length and age).
a, CT of N1 negatively correlated with refractive error (diopter) (R2 = 0.239, p = 0.000).b, CT of N1 positively correlated with axial length (R2 = 0.180, p = 0.000).c, CT of N1 positively correlated with age (R2 = 0.069, p = 0.007). N1 = 1mm nasal to fovea.