RNFL Thickness Difference Between Children Under and Over 11 Years
Based on the available evidence, there is no clinically significant difference in average RNFL thickness between children younger than 11 years and those 11 years or older—age does not independently affect RNFL thickness in healthy children.
Key Finding: Age Independence
The most robust evidence consistently demonstrates that age has no significant independent effect on RNFL thickness in the pediatric population when controlling for other factors:
In a large study of 470 schoolchildren aged 7-12 years, multiple linear regression analysis controlling for age, gender, cycloplegic treatment, and signal strength found that only spherical equivalent refraction significantly affected RNFL thickness (p < 0.001), not age 1.
A study of 148 eyes in children aged 4-17 years confirmed no effect of age on RNFL thickness in either females or males 2.
In 92 children aged 4-17 years, while univariate analysis initially suggested age had an effect (p = 0.013), when controlling for refraction, age no longer had a significant effect on RNFL thickness 3.
A study of 83 children aged 5-15 years found that while central subfield macular thickness correlated with age, the peripapillary RNFL measurements showed no age-dependent variation 4.
Reference Values Across Age Groups
Average RNFL thickness measurements are remarkably consistent across pediatric age ranges:
- Ages 7-12 years: 109.4 ± 10.0 μm 1
- Ages 4-17 years: 107.0 ± 11.1 μm 3
- Ages 5-15 years: 107.6 ± 1.2 μm 4
- Ages 4-17 years: 94 ± 10.9 μm (right eye) 2
- Ages 5-16 years: 98.4 ± 7.88 μm 5
What Actually Matters: Refractive Error
The primary determinant of RNFL thickness variation in children is spherical equivalent refraction, not age:
- For every diopter change toward hyperopia, average RNFL thickness increases by 1.7 μm 1.
- RNFL thickness decreases by 1.9 μm for every 1 diopter increase in myopic shift (p < 0.001) 2.
- Refraction was the only factor with consistent significant effect across multiple studies 1, 3, 2.
Clinical Implications
When evaluating RNFL thickness in children:
- Do not expect thinner RNFL measurements in younger children compared to those over 11 years 1, 3, 2.
- Always account for refractive error when interpreting RNFL measurements, as this is the primary variable affecting thickness 1, 2.
- Be aware that normal variation in pediatric RNFL thickness is large (ranges from approximately 78-135 μm), making individual assessment challenging 3.
- Axial length also influences RNFL thickness (1.9 μm decrease per mm increase), which correlates with refractive error 2.