Related Experiment Video
Updated: Jun 23, 2026
Using Retinal Imaging to Study Dementia
Published on: November 6, 2017
Peripapillary retinal nerve fiber layer thickness analysis with scanning laser polarimetry (GDx VCC) in normal
Maria Letizia Salvetat1, Marco Zeppieri, Mirella Felletti
1Department of Ophthalmology, Azienda Ospedaliero-Universitaria Santa Maria della Misericordia, Udine, Italy.
Insights
Scanning laser polarimetry with variable corneal compensation (GDx VCC) shows significant age-related thinning of the retinal nerve fiber layer in children. Adult normative data for GDx VCC should not be used for pediatric assessments.
Area of Science:
- Ophthalmology
- Optometry
- Biomedical Engineering
Background:
- The scanning laser polarimeter with variable corneal compensation (GDx VCC) is a tool used to measure retinal nerve fiber layer (RNFL) thickness.
- Accurate RNFL measurements are crucial for diagnosing and monitoring glaucoma and other optic neuropathies.
- Normative databases are essential for interpreting GDx VCC results, but their applicability across different age groups requires validation.
Purpose of the Study:
- To evaluate the utility of GDx VCC in pediatric populations.
- To compare GDx VCC parameters between normal children and adults.
- To investigate age-related variations in peripapillary RNFL thickness in healthy individuals.
Main Methods:
- Ninety-eight normal children (ages 3-17) and 96 normal adults (ages 18-87) underwent GDx VCC testing.
- Exclusion criteria included eyes with abnormally small or large optic discs.
- Analysis involved "extended parameter table" values, mean thickness in quadrants and sectors, and statistical comparisons using t-tests, ANOVA, and regression analysis.
Main Results:
- GDx VCC parameters exhibited substantial intersubject variability in both children and adults.
- Most parameters, except Symmetry, were significantly higher in children compared to adults (P<0.05).
- Significant age-related thinning was observed in the temporal-superior-nasal-inferior-temporal (TSNIT) average, superior average, and inferior average RNFL parameters (P<0.01).
Conclusions:
- GDx VCC revealed significant age-related thinning in the superior and inferior peripapillary RNFL in the studied population.
- Marked differences in GDx VCC parameters between children and adults indicate that the standard adult normative database is inappropriate for pediatric use.
- This study underscores the need for age-specific normative data for GDx VCC in children.
Purpose:
To assess the use of scanning laser polarimeter with variable corneal compensation (GDx VCC) in children; to compare GDx VCC parameters between normal children and adults; and, to evaluate peripapillary retinal nerve fiber layer thickness variation with age in normals.
Patients And Methods:
Ninety-eight normal children (mean age 8.5+/-2.8 y; range: 3 to 17) and 96 normal adults (mean age of 47.0+/-20.4 y; range: 18 to 87) underwent GDx VCC testing. Eyes with small or large optic discs were excluded. The "extended parameter table" parameters and mean thickness values of the 4 quadrants and 64 sectors were considered. Differences between age groups, retinal thickness comparisons and age effect were assessed using unpaired t test, analysis of variance, and regression analysis.
Results:
GDx VCC parameters in children and adults showed wide intersubject variability. All parameters, excluding Symmetry, were significantly greater in children (P<0.05). TSNIT (temporal, superior, nasal, inferior, temporal) average, superior average and inferior average parameters showed a significant age-related thinning (P<0.01), at a rate of 0.043, 0.057, and 0.121 microm/y, respectively.
Conclusions:
A significant age-related superior and inferior retinal nerve fiber layer thinning was found using GDx VCC. Considering the significant differences between children and adults for most GDx VCC parameters, the built-in adult normative database cannot be applied in children.
