Retinal Nerve Fiber Layer Thickness Estimated with Spectral-Domain Optical Coherence Tomography in Normal Children

Der-Chong Tsai

Purpose: To measure the peripapillary retinal nerve fiber layer (RNFL) thickness with spectral-domain optical coherence tomography (OCT) in normal children, and to evaluate the effect of age and spherical equivalent (SE) of refractive error on RNFL thickness.

Methods: This was a school-based cross-sectional study enrolling 470 healthy students, 265 (136 boys) were Year 1 and 205 (100 boys) were Year 6. RNFL thickness was measured with RTVue-100 OCT (Optovue Inc, Fremont, CA, USA). RNFL3.45 scan was used. Refractive errors were measured by cycloplegic autorefraction. SE was calculated in diopters (D), and data from right eyes were reported.

Results: Mean ages (±standard deviation [SD]) were 7.1±0.3 and 12.0±0.3 years for Year 1 and 6 students. The mean global RNFL thickness (±SD) was 109.4± 10.0μm. The quadrant RNFL thicknesses were 90.4± 14.3μm (temporal), 142.2± 19.5μm (inferior), 71.1± 11.3μm (nasal), and 133.9± 18.1μm (superior). Mean SE was significantly different between 2 age groups (0.2±1.0 D in Year 1; -1.9±2.1 D in Year 6, p<0.001). Multiple linear regression analysis disclosed that only the SE has the significant effect on RNFL thickness after controlling for gender and age. (p<0.001).

Conclusions: Our study provides the reference values of RNFL thickness measured with latest generation of OCT for children. Refraction, not age, has profound effect on RNFL thickness among schoolchildren.