Topographic distribution features of the choroidal and retinal nerve fiber layer thickness in Chinese school-aged...

To explore the topographic distribution features of choroidal thickness (CT) and retinal nerve fiber layer thickness (RNFLT), and determine the relationship between CT and ocular parameters in school-aged children.

The healthy school-aged children with low ametropia or emmetropia in Wenzhou were recruited for this cross-sectional study. With high-density optical coherence tomography (HD-OCT) combined with MATLAB software, the CT and RNFLT values in the macular area were measured at different locations and compared. Statistical analyses were performed to evaluate the correlation between CT and ophthalmic parameters, such as spherical equivalent (SE) and the axial length (AL).

A total of 279 school-aged children with 8.00±1.35 years of mean age (range, 6-10y) were included. The mean AL was 23.66±0.86 mm. The mean CT in CT-C (264.31±48.93 µm) was thicker than that in CT-N1 (249.54±50.52 µm), and the average CT in the parafoveal region was also thicker than that in CT-N2 (235.65±50.63 µm). The subfoveal CT also varied substantially across refractive errors (P<0.001), and those with myopia (250.59±47.01 µm) exhibited a thinner choroid compared with those with emmetropia (278.74±48.06 µm). CT negatively correlated with AL (y=-21.72x+779.17; R ²=0.1458), and positively correlated with SE (y=15.76x+271.9; R ²=0.0727, OD; y=18.31x+269.8; R ²=0.1007, OS). The average RNFLT was thickest in the peripapillary region (236.35±19.03 µm), the mean RNFLT-S (131.10±15.16 µm) was thicker than the RNFLT-I (128.20±16.59 µm), and the mean RNFLT-T (76.54±11.99 µm) was thicker than the RNFLT-N (64.28±8.55 µm). The variations in the RNFLT between quadrants did differ between those with myopia and emmetropia (P<0.05).

We establish demographic information for the choroid and RNFLT. These findings provide information that should be considered in future analyses of the CT and RNFLT in OCT studies in school-aged children.