Estimating retinal nerve fiber layer thickness in normal schoolchildren with spectral-domain optical coherence tomography

To measure the peripapillary retinal nerve fiber layer (RNFL) thickness in normal schoolchildren with spectral domain optical coherence tomography (SD-OCT), and to evaluate the effects of age, spherical equivalent (SE) refraction, OCT signal strength, and cycloplegic treatment on RNFL thickness. Comprehensive ophthalmic examinations were performed at a school visit. RNFL thicknesses were measured with RTVue-100 OCT. Refractive errors were measured by cycloplegic autorefraction. Four hundred seventy healthy schoolchildren aged 7 and 12 were enrolled. The average RNFL thickness (mean +/- A SD) was 109.4 +/- A 10.0 mu m. The quadrant RNFL thicknesses were 90.4 +/- A 14.3 mu m (temporal), 142.2 +/- A 19.5 mu m (inferior), 71.1 +/- A 11.3 mu m (nasal), and 133.9 +/- A 18.1 mu m (superior). After controlling for age, gender, cycloplegic treatment, and signal strength index, multiple linear regression analysis disclosed that only SE refraction has a significant effect on RNFL thickness, (p < 0.001). For every diopter change towards hyperopia, the average RNFL thickness increased by 1.7 mu m. SE refraction was positively correlated with RNFL thickness in most sectors of nontemporal quadrants, but it was negatively correlated with RNFL thickness in sectors of temporal quadrants. Our study provides reference values of pediatric RNFL thickness measured with SD-OCT. SE refraction is the only significant predictor of RNFL thickness.