MRI-based normative orbital anthropometric measurements in pediatric populations: age-related variations and clinical...

Accurate anthropometric data of the pediatric orbit is critical for diagnosing and managing various pediatric orbital pathologies and for planning surgical and reconstructive interventions. The purpose of this study was to establish MRI-based normative anthropometric data for pediatric orbital structures, analyze age-related variations, and evaluate interobserver reliability among expert neuroradiologists.

This retrospective study included 64 healthy pediatric patients (32 males, 32 females; age range, 1-17 years) who underwent MRI scans for indications unrelated to orbital pathology. Patients were categorized into three age groups: pre-school (3-6 years), school-age (7-12 years), and adolescent (13-17 years). MRI scans acquired at 1.5 Tesla and 3 Tesla were independently evaluated by three neuroradiologists to measure orbital anthropometric parameters, including extraocular muscle dimensions, orbital breadth, orbital height, interzygomatic line length, intercanthal distance, optic nerve sheath width, and optic nerve angle. Statistical analyses included Spearman's correlation, Kruskal-Wallis tests, Mann-Whitney U tests, and intraclass correlation coefficients (ICC) to assess interobserver reliability.

Significant positive correlations were identified between patient age and orbital parameters, particularly the interzygomatic line length (Spearman's r = 0.772, p < 0.001). Orbital breadth (right: r = 0.674; left: r = 0.703) and orbital height (right: r = 0.608; left: r = 0.644) also significantly increased with advancing age (all p < 0.001). Interobserver reliability demonstrated excellent reproducibility, with ICC values notably high for orbital breadth (ICC = 0.92, 95% CI: 0.89-0.95) and orbital height (ICC = 0.90, 95% CI: 0.87-0.93).

MRI-based normative anthropometric measurements provide precise and reliable reference values for pediatric orbital anatomy. These measurements reveal significant age-related developmental trends, enhancing diagnostic accuracy, clinical management, and surgical planning in pediatric orbital conditions.