The morphology of optic disc and the thickness of retinal nerve fiber layer in a population of 9-year-old children in North China

Optic disc morphology and retinal nerve fiber layer (RNFL) thickness have been widely studied in populations with refractive error. This study aims to measure and analyze optic disc parameters and RNFL thickness in different regions of the optic disc in 9-year-old schoolchildren. It also seeks to investigate the influence of factors such as refractive error, axial length, gender, and body mass index (BMI) on these ocular parameters. This cross-sectional study included 1274 children aged 9 years. Participants underwent anthropometric measurements and comprehensive ophthalmic examinations, including axial length (AL), non-cycloplegic autorefraction, and optical coherence tomography (OCT). Continuous variables are presented as mean ± standard deviation or median (interquartile range). Group comparisons were performed using the Wilcoxon rank-sum test or Kruskal–Wallis test. The RNFL thickness showed the typical distribution pattern, being greatest in the inferior quadrant, followed by the superior, temporal, and nasal quadrants. No significant differences in optic disc parameters or RNFL thickness were observed across gender or BMI groups (all P > 0.05). Compared with non-myopic participants, cup-related parameters were smaller in myopic groups. Greater myopic refractive error was associated with increased global and nasal RNFL thickness. Eyes with AL ≥ 26 mm showed thicker nasal RNFL than those with AL < 26 mm (P = 0.01), with no other significant differences. In 9-year-old children from North China, optic disc morphology and RNFL thickness varied with refractive and ocular biometric characteristics. RNFL thickness was associated with refractive error and axial length.