Abstract
Purpose: :
To asses agreement between one Time-Domain (Stratus) and two Fourier-Domain (Cirrus and 3D OCT-1000) Optical Coherence Tomography (OCT) devices for the measurement of the retinal nerve fiber layer (RNFL) thickness.
Methods: :
Observational, comparative, cross-sectional study. In this institutional study, 58 patients (116 eyes) with afferent visual pathway pathology were included. A triple RNFL thickness OCT examination with Stratus, Cirrus and 3D OCT-1000 was done for every patient, in both eyes. Eyes with refractive errors of +/-6D spherical, 3D cylinder, fixation difficulties or Analysis of Confidence (AC) less than 6 were excluded. The average RNFL thickness, by quadrants and by clock-hour sectors were compared with the Lin's Concordance Correlation Coefficient (Lin) and Bland and Altman graphic approach.
Results: :
RNFL thickness were higher when measured by 3D OCT-1000 (92 microns average, Range: 11-240) in all cases, except 12 and 6 clock-hour sectors which were higher by Stratus. Almost perfect agreement between Stratus and Cirrus were obtained (Lin 0.86, 95%CI 0.85-0.88) whereas agreement between Stratus and Cirrus vs 3D OCT-1000 was only substantial (Lin 0.72, 95%CI 0.69-0.74 and 0.69, 95%CI 0.66-0.71 respectively).
Conclusions: :
3D OCT-1000 provides de highest RNFL thickness values, except in the 12 and 6 clock-hour sectors where Stratus does it. Despite agreement between Stratus and Cirrus was almost perfect, between 3D OCT-1000 and Stratus or Cirrus is too low to be comparable.
Keywords: neuro-ophthalmology: diagnosis • optic nerve • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)