Abstract
Purpose: :
To evaluate the relative reproducibility of retinal thickness measurements from spectral domain (SD-OCT; Topcon: 3D-OCT1000) and time domain (TD-OCT; Carl Zeiss Meditec: Stratus) optical coherence tomography (OCT).Methodology: Replicate measurements on each eye with each OCT instrument was performed on 138 eyes of 73 subjects in a University Retina Clinic. Subjects had a spectrum of diagnoses (Age related macular degeneration =30, Diabetic macular edema=16, Retinal vein occlusions =5, no acute disease (normal fellow eyes) =10, other =12). Macular thickness measurements of the 9 standard subfields were obtained and compared.
Results: :
The coefficient of repeatability (23 vs. 25) and the coefficient of variation (3% vs. 4%) of retinal thickness measurements in the central subfield were lower by SD-OCT as compared to TDOCT. The intraclass correlation coefficient (ICC) for central subfield measurements was 0.99 by both instruments, demonstrating high intrasession repeatability. The absolute difference between SD-OCT and TD-OCT for central subfield thickness (mean ±SD) was 22.1µ ± 26.5µ, mean inner subfield was 15.1µ ± 12.7µ and mean outer subfield was 11.9µ ± 7.4µ.
Keywords: clinical (human) or epidemiologic studies: systems/equipment/techniques • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • retina