Relationship between Age and Retinal Nerve Fiber Layer Thickness in Normal Children

Purpose: To evaluate the effect of age and ocular factors on peripapillary retinal nerve fiber layer (RNFL) thickness in children. Method: A total of 198 normal subjects aged <19 years received a comprehensive ophthalmologic examination, including measurement of visual acuity, axial length, and cycloplegic refraction. Fast optical coherence tomography RNFL scans were obtained and average RNFL thickness was adjusted for ocular magnification. One eye of each subject was randomly selected as the study eye. The correlations between age and other ocular variables were examined. Results: Mean subject age was 8.61 ± 3.12 years. Average RNFL thickness and ocular magnification-corrected average RNFL thickness were 107.71 ± 11.83 and 103.03 ± 12.53 μm, respectively. There was no significant correlation between observed RNFL thickness and spherical equivalent of the refractive error (SE), axial length, or age (all P >0.05). Corrected RNFL thickness was positively correlated with age and axial length and negatively correlated with SE (P <0.01). Age was negatively correlated with the percent difference between observed and corrected RNFL thickness (P <0.001). Multivariate linear regression analysis showed that both axial length and age were correlated with corrected RNFL thickness in subjects <15 years old (P <0.05). Conclusion: The RNFL thickness is likely to be overestimated in children <15 years old. Additionally, an RNFL thickness increase was observed in children <15 years old. Thus, ocular magnification and RNFL thickness increase should be considered when assessing RNFL thickness in patients <15 years old.