Comparison of three optical coherence tomography devices, one time-domain and two fourier-domain, for the estimation of the retinal nerve fibre layer thickness

Abstract

PurposeTo assess agreement between one system of time-domain optical coherence tomography (OCT) (Stratus) and two systems of fourier-domain OCT (Cirrus and 3D OCT- 1000) for the measurement of the retinal nerve fibre layer thickness (RNFL). MethodsFifty eyes from 25 patients with neuro-ophthalmological disorders of the afferent visual pathway were included. A triple RNFL thickness OCT examination with Stratus, Cirrus and 3D OCT-1000 was performed on both eyes of every patient, on the same day and by the same technician. The average RNFL thickness by quadrants and clock sectors were compared with the Lińs concordance correlation coefficient (CCC) and Bland-Altman plots. ResultsThe average RNFL thickness, the temporal and nasal quadrants and corresponding clock sectors, was higher by 3D OCT-1000 (mean 90.02 microns), nevertheless, RNFL thickness of the superior and inferior quadrants and corresponding clock hours was higher when measured by Stratus device. The CCC agreement between Stratus and Cirrus was high (0.820), between Stratus and 3D OCT-1000 was moderate (mean 0.573) and between Cirrus and 3D OCT-1000 was moderate with a mean of 0.564 but too low in the nasal and temporal quadrants (0.362 and 0.347 respectively). ConclusionsThe RNFL thickness measurements by Stratus, Cirrus and 3D OCT-1000 OCT are not equivalent. Although the agreement between Stratus and Cirrus was high, it was too low between 3D OCT-1000 and Stratus or Cirrus.