First Author: G.Martone ITALY
Co Author(s): C. Traversi E. Nuti P. Pichierri G. Cartocci 0 0 0 0 0 0 0 0 0
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The aim of this study was to investigate the repeatability of manual measurements of subfoveal choroidal thickness (SFCT) on the images obtained by two spectral-domain optical coherence tomographic (SD-OCT) instruments.
Ophthalmology Department, University of Siena, Italy
A cross-sectional, prospective noninterventional study in which SFCT was measured in the images obtained by two SD-OCT instruments: Topcon 3D OCT-2000 (Topcon-SD-OCT) and Cirrus HD-OCT (Zeiss-SD-OCT). Two masked experienced OCT readers independently, manually determined the SFCT, After manual segmentation, the measurements were made using the calipers provided by the software of the proprietary device. The readers were masked to each other's readings. Intraobserver, interobserver, and intermachine agreements were assessed.
We examined 25 healthy eyes and 25 eyes with nonproliferative diabetic retinopathy (NPDR). The intraobserver correlation coefficient (95% confidence interval) in healthy and NPDR eyes was 0.989 and 0.993 for Topcon-SD-OCT and 0.992 and 0.991 for Zeiss-SD-OCT (p<0.002), respectively. The interobserver correlation coefficient in healthy and NPDR eyes was 0.994 and 0.992 for Topcon-SD-OCT and 0.993 and 0.992 for Zeiss-SD-OCT (p<0.001). The average SFCT in healthy eyes was 283.1μm with Topcon-SD-OCT and 279.3 μm with the Zeiss-SD-OCT. The average SFCT in eyes with NPDR was 242.2μm with Topcon-SD-OCT and 245.6 μm with the Zeiss-SD-OCT. The intermachine correlation coefficient was 0.981 for Topcon-SD-OCT versus Zeiss-SD-OCT. The difference in SFCT was not statistically significant between both devices.
In normal and NPD eyes, there was good reproducibility and repeatability of SFCT measurements that were strongly correlated. Future studies are required to estimate the repeatability of SFCT measurements in patients with other chorioretinal pathology.