Purpose:
To compare and correlate retinal nerve fiber layer (RNFL) thicknessassessed by two different technologies, the optical coherencetomography (Stratus OCT) and the laser scanning polarimetrywith variable corneal compensator (GDx VCC).
Methods:
Thirty-seven eyes of 37 normal individuals were scanned withStratus OCT and GDx VCC to assess the RNFL thickness. The mean(± SD) age was 22.70 (± 3.46) years. The FastRNFL Thickness 3.4 protocol and GDx VCC 2.8 mm standard scancircle were used for obtaining images in all subjects. Pupilswere dilated for OCT images only. GDx VCC TSNIT Average, SuperiorAverage and Inferior Average, as well as Stratus OCT AverageThickness, Superior Average and Inferior Average parameterswere assessed and compared.
Results:
GDx VCC mean (± SD) TSNIT Average, Superior Average andInferior Average were 57.73 (± 8.92), 70.84 (±6.82)and 68.13 (±8.92), respectively. Stratus OCT mean (±SD) Average Thickness, Superior Average and Inferior Averagewere 107.75 (± 9.45), 131.92 (± 15.37) and 137.49(± 15.02), respectively. Pearson correlation coefficientsfor these parameters were 0.62 (P<0.001), 0.43 (P<0.01)and 0.71 (P<0.001), respectively.
Conclusions:
RNFL thickness obtained by GDx and OCT presented moderate tostrong correlation, but OCT measurements were about two-foldthicker. Therefore, RNFL thickness data obtained by GDx VCCand Stratus OCT are not interchangeable.
Keywords: nerve fiber layer • imaging/image analysis: clinical • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)