Retinal nerve fiber layer thickness obtained by optical coherence tomography in healthy preschool age children

Purpose: To determine the normative values of retinal nerve fiber layer (RNFL) thicknesses obtained by optical coherence tomography (OCT) in healthy preschool age children and to investigate the effects of age, sex, axial length, and optic disc morphology on the measurements.Materials and Methods: One hundred and seventy two eyes of 111 healthy children with age between 3 and 6 were measured for optic disc morphology and RNFL thicknesses by OCT. The measurement of axial length and routine eye examination were performed in all eyes. Data was statistically analyzed.Results: Fifty three of 111 healthy children were female and 58 were male. The mean age of the children was 57.48±11.87months. The means of Global RNFL (G-RNFL), superior RNFL (S-RNFL), inferior RNFL (I-RNFL), temporal RNFL (T-RNFL), and nasal RNFL (N-RNFL) were 105.5±11.5 μm; 131.08±19.14 μm; 132.38±20.10 μm; 76.0±14.90 μm and 82.88±17.85 μm, respectively. Girls' RNFL was thinner than the boys', but this difference was not statistically significant. There were negative correlations between age and all parameters of RNFL measurement except nasal RNFL. The only parameter, that has statistically significant correlation between age, was T-RNFL (r=-0,.213, p=0.011). Also,there were statistically significant negative correlations between axial length and the thicknesses of S-RNFL, I-RNFL, and G-RNFL (r=-0.245, p=0.004; r=-0.243, p=0.004; r=-0.255, p=0.002; respectively). Positive correlations between rim area and the thicknesses of S-RNFL, I-RNFL, and G-RNFL were significant (r=0.205, p=0.015; r=0.183, p=0.03; r=0.251, p=0.003; respectively).Conclusion: The normative values of RNFL thicknesses in preschool age children were found thinner than the black and Asian children's values, and similar to white children's. Age, axial length, and optic disc morphology of the children may affect the measurements whereas no significant effect of gender on the measurements.