The Distribution of Ocular Normative Parameters in a Spanish School Population

<b>Background/Objectives</b>: The prevalence of myopia is increasing globally, including in Spain. The early detection of ocular biometric parameters associated with myopia development is crucial for implementing control strategies. This study aims to describe the normative biometric values in a Spanish school-aged population and compare them with previously established reference data. <b>Methods</b>: A cross-sectional, observational, and analytical study was conducted on 558 students aged 6 to 12 years from the Educare Valdefuentes School in Madrid. Ocular biometric parameters, including axial length (AL), corneal curvature (CR), anterior chamber depth (ACD), crystalline lens thickness (LT), corneal thickness (CCT), and posterior vitreous depth (PVD), were measured using IOLMaster 700. The axial length/corneal radius (AL/CR) ratio was calculated. Percentile growth curves were generated, and the results were statistically analyzed using IBM SPSS 29. <b>Results</b>: AL significantly increased with age (<i>p</i> < 0.001), and boys had longer AL than girls. The AL/CR ratio showed a moderate correlation with myopia risk (ρ = 0.647, <i>p</i> < 0.001). Compared to previous European studies, no significant differences were found, except for minor variations in AL and CR. <b>Conclusions</b>: These percentile-based biometric values provide a useful reference for monitoring ocular growth and assessing myopia risk in Spanish children. The AL/CR ratio remains a strong predictor of myopia development, supporting its role in early detection strategies.