Exploration of a new method in measurement of choroidal thickness in children and teenagers by EDI-OCT

Abstract Purpose: Using EDI-OCT and combining it with a self-built program to achieve choroidal thickness measurement in a simple and easy way. Measurement and analysis of choroidal thickness in normal children and adolescents. Methods: Twenty healthy volunteers (40 eyes) were randomly recruited. The choroidal images of healthy volunteers were obtained by EDI-OCT mode. The anterior choroidal boundary (Bruch membrane) was automatically generated by Heidelberg software. At the same time, the posterior choroidal boundary was manually depicted with the drawing tool in OCT software. A program was written to calculate choroidal thickness to verify the repeatability of the method. OCT images were collected from 99 children and adolescents aged 7-18 years. These choroidal was measured by the method previously verified. Results: 1. ICC was 0.975, 95% CI was [0.959, 0.984], p≤0.001. 2. The average thickness of the choroid in the horizontal direction is 249.17±68.84μm in the 3mm range, and it was 258.24±69.63μm in the vertical direction. The correlation coefficients of choroidal thickness and axial length in horizontal and vertical directions were -0.642, -0.624 (p≤0.001, p≤0.001). The correlation coefficients between choroid thickness and diopter in horizontal and vertical directions were 0.610, 0.583 (p≤0.001, p≤0.001). Conclusion: 1. The experimental method has good repeatability and can calculate the average thickness of the choroid through pixels. 2. There was a weakly significant correlation between choroidal thickness and age, but significant with axial length and diopter. 3. It is simple to operate, requires low computer knowledge, and can be accepted more easily by clinicians and researchers. And it can be widely used in the field of EDI-OCT.