Thicker peripapillary choroid may be associated with behavioral factors in Tokyo's children.

The study goals were measurement of the choroidal thickness (CT) and investigation of related factors among children. Third-grade students at an elementary school in Tokyo participated in this study. A total of 119 schoolchildren underwent measurements of the axial length (AL), non-cycloplegic objective refraction (SE), and CT. The CT was divided into nine regions: the subfoveal area with a diameter of 1 mm (C0), a 5-mm-diameter circle-C0 (C1), and a 9-mm-diameter circle (C2); each was further divided into four quadrants. The SE, AL, and C0 CT were, respectively, - 1.57 ± 1.56 diopters, 23.39 ± 0.80 mm, and 297.73 ± 57.88 μm. Multiple regression analysis showed that the time spent using a computer was associated significantly with the CT in the C0 and the inferior C2 (C0: β = -0.728, P = 0.028; inferior C2: β = -0.527, P = 0.048), and the reading distance was associated significantly with the CT in the superior and nasal C2 (superior, β = 1.664, P = 0.007; nasal, β = 1.128, P = 0.015). In addition, time spent using smartphones, tablets, or handheld gaming devices was associated significantly with the CT in the superior and inferior C2 (superior C2: β = 0.259, P = 0.018; inferior C2: β = 0.262, P = 0.013). In conclusion, reading distance and time spent on digital devices may be associated with choroid thickness in children.