Symmetry of optical coherence tomography retinal measurements in young children

Abstract

Purpose: To examine symmetry of macular, peripapillary nerve fiber layer (NFL), and optic disk measurements in healthy children.

Design: Cross-sectional study.

Methods: We examined a population-based sample of six-year-old children (n = 1,765) in the Sydney Childhood Eye Study. Optical coherence tomography (OCT) scan data for right and left eyes were compared.

Results: High interocular correlations (>0.8) were found for foveal minimum thickness and cup-to-disk ratios. Average NFL thickness was moderately correlated (0.7). Other macular, NFL, and optic disk parameters showed negligible or small mean interocular differences. In 95% of children, interocular difference in macular thickness was <22 microm for foveal minimum and <40 microm for other areas, and 16 to 17 microm for average NFL thickness. Cup-to-disk ratio was highly symmetric, varying by <0.25 in 95% of children.

Conclusions: Interocular asymmetry of retinal/optic disk parameters should be interpreted in the context of other clinical measures because of the potential for large degrees of asymmetry among individuals.