Optic Nerve Sheath Diameter in Pediatric Populations: Establishing Reference Intervals and Anthropometric Correlations

OBJECTIVES: Ultrasonographic measurement of optic nerve sheath diameter (ONSD) is emerging as a noninvasive method for assessing intracranial pressure (ICP) in children. However, its practical application is limited by the lack of adequate age-specific normative data for healthy children. This study aimed to establish age-specific reference ranges for ONSD in healthy children aged 4 to 18 years and assess how anthropometric factors such as body mass index (BMI), height, and weight affect ONSD measurements. METHODS: This cross-sectional study included 150 healthy children aged 4 to 18 years, with no suspicion of increased ICP or chronic illness. ONSD was measured bilaterally using standardized transorbital ultrasonography. Anthropometric z -scores were calculated and correlations and percentile-based reference intervals were determined. RESULTS: The mean ONSD was 3.67±0.50 mm, with higher values in the 11 to 18 years group compared with the 4 to 10 years group (3.80±0.45 mm vs. 3.51±0.51 mm, P