RT Journal Article
A1 Wolf-Schnurrbusch, U. E.
A1 Brinkmann, C. K. M.
A1 Rothenbühler, S.
A1 Ceklic, L.
A1 Wolf, S.
T1  Macular Thickness Measurements in Healthy Eyes Using 5 Different OCT Instruments
JF Investigative Ophthalmology & Visual Science
JO Invest. Ophthalmol. Vis. Sci.
YR 2008
VO 49
IS 13
SP 1855
OP 1855
SN 1552-5783
AB    To report foveal thickness measurements in healthy eyes using the different commercially available optical coherence tomography (OCT) instruments and evaluate the reproducibility of the different instruments.     Macular thickness measurements were obtained from 20 normal subjects examined with 5 different OCT instruments. The (1) Stratus OCT (Carl Zeiss Meditec, Jena, Germany), (2) Spectralis OCT+HRA (Heidelberg Engineering, Dossenheim, Germany), (3) OCT/SLO (Oti, Toronto, Canada), (4) Cirrus HD-OCT (Carl Zeiss Meditec, Jena, Germany), and (5) SOCT Copernicus (Optopol Technology, Zawiercie, Poland) were used to assess central retinal thickness (CRT, mean thickness in the central 1000-µm diameter area) at two different sessions on one randomly chosen eye of each subject. We calculated the coefficient of variation for repeated measurements as measure for repeatability.     Measurement of CRT was possible in all eyes. The CRT was 215 ± 23 µm for the Stratus OCT, 289 ± 23 µm for the Spectralis OCT+HRA, 281 ± 26 µm for the Cirrus HD-OCT, 236 ± 33 µm for the OCT/SLO, and for the SOCT 263 ± 24 µm respectively. As compared with the Stratus OCT all other instruments showed significant higher values for CRT. The coefficients of variation for repeated measurements was 4.23 % for the Stratus OCT, 1.01% for the Spectralis OCT+HRA, 5.70% for the Cirrus HD-OCT, 3.01% for the OCT/SLO, and for the SOCT 3.53% respectively. As compared to the Stratus OCT only the Spectralis OCT+HRA had a significant lower variation between two measurements. The other instruments had similar coefficients of variation for repeated measurements.     Measurements of CRT differ significantly between the different OCT instruments. There are several differences between the instruments. These include different methods of segmentation of the retinal boarders, different methods of sampling the measurement points, and probably different estimates for the optical indices of the retina. The only instrument with a very high reproducibility is the Spectralis OCT+HRA. This may be due to the automatic alignment and registration of the OCT scans which is a unique feature of this instrument.   
RD 4/9/2020