Reproducibility of macular retinal nerve fiber layer and ganglion cell layer thickness measurements in a healthy pediatric population

Purpose: To evaluate the reproducibility of Spectralis spectral domain-OCT segmented ganglion cell layer (GCL) and macular retinal nerve fiber layer (mRNFL) measurements in a healthy children population. Methods: An observational, cross-sectional study was carried out on 79 children to measure the intraobserver reproducibility and the repeatability between a novel and an experienced operator of the segmented macular GCL and mRNFL. Interobserver and intraobserver reproducibility were defined by the intraclass correlation coefficient (ICC) and coefficients of variation (COV). Kruskal-Wallis test was used to determine statistical significance in the COV of three age groups children (younger than 6 years, between 6 and 12, and older than 12 years old). Results: The results from the intraoperator GCL thickness analysis were highly reproducible (COV < 6%) and reliable (ICCs > 0.81). When the measurements were compared between a novel and an experienced examiner lower ICCs and higher COV were found. COVs ranged from 1.85% (total volume area) to 5.57% at the central ETDRS subfield while the ICC vary from 0.632 (outer inferior) to 0.832 (inner inferior). The repeatability and reproducibility of the mRNFL thickness were lower, with ICCs ranging from 0.428 to 0.872 in the interobserver analysis and from 0.897 to 0.346 in the interobserver one. Conclusion: In the present study, we establish substantial reliability of the GCL thickness in children with Spectralis(R)SD-OCT in all the sectors, albeit lower than the reported in the literature with other SD-OCTs and in adults. The reproducibility and repeatability of the mRNFL were significantly lower. We were unable to find consistent statistical significant differences between the COV of the three age groups.