Purpose:
To demonstrate the distribution of the retinal nerve fiber layer (RNFL) thickness across normals as measured by CirrusTM HD-OCT Spectral Domain Technology (Carl Zeiss Meditec, Dublin, CA).
Methods:
Two hundred and thirty-nine normal subjects were imaged at seven sites using Cirrus HD-OCT, with an optic disc cube scan that included 200x200 axial scans. The cube was segmented to identify the borders of the internal limiting membrane and the outer boundary of the RNFL. The difference between these two represents the RNFL thickness. Mean average, superior, inferior, nasal, and temporal RNFL thicknesses were calculated. Furthermore, the RNFL thicknesses were displayed as a false color thickness map, "RNFL Thickness Map." The thickness maps were then qualitatively reviewed.
Results:
Mean average, superior, inferior, nasal and temporal RNFL thicknesses (Standard Deviation) were 93.42 (9.30), 117.52 (15.53), 122.76 (15.69), 69.03 (11.90), 64.35 (11.22) µm, respectively. Review of the thickness maps demonstrated various RNFL distribution patterns in normal subjects (Figure).
Conclusions:
Mean RNFL thickness values for CirrusTM HD-OCT were determined. It was found that RNFL distribution varied in normal subjects.
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • nerve fiber layer • imaging/image analysis: clinical