Abstract
Purpose:
To compare the feasibility and reproducibility of choroidal thickness measurements in two different optical coherence tomography devices.
Methods:
Consecutive patients seen in our department between June 17th and June 26th 2013 underwent an optical coherence scan of the macula with a single foveal-centered high definition raster line (HD-Cirrus; Carl Zeiss Meditec) and a single foveal-centered enhanced depth imaging line (Spectralis; Heidelberg Engineering). Firstly, a qualitative assessment of the identification of the interface between the sclera and the choroid was evaluated. Secondly, choroidal thickness (CT) values were calculated with the manual caliper provided by the software in five regions in each scan: subfoveal, 500 microns temporal and nasal from the fovea, and 1000 microns temporal temporal and nasal from the fovea. The OCT scans were analyzed by three independent observers (I.P.C, P.H.M and F.E).
Results:
A total number of 94 eyes of 47 patients were included. The scleral-choroidal interface was recognized in a mean of 49.57% of cases with HD-Cirrus and 74.54% of cases with Spectralis, considering all the analyzed locations (p<0.001). Paired Student’s t test revealed no significant differences between HD-Cirrus and Spectralis in CT measurements at any of the analyzed locations: subfoveal: 190 ± 58 versus 191 ± 66 respectively (p=0.59); 500 microns temporal from the fovea: 189 ± 59 versus 192 ± 59 (p = 0.301 ); 500 microns nasal from the fovea: 181 ± 60 versus 185 ± 64 (p= 0.318); 1000 microns temporal from the fovea: 183 ± 59 versus 192 ± 62 respectively (p= 0.188); 1000 microns nasal from the fovea: 174 ± 60 versus 176 ± 59 respectively (p= 0.459).
Conclusions:
There was good reproducibility among CT measurements obtained with Cirrus and Spectralis. Overall, a single foveal-centered enhanced depth imaging line obtained with Spectralis might be superior to a single foveal-centered high definition raster line obtained with HD-Cirrus in order to assess choroidal thickness. Further studies are warranted in order to confirm our preliminary data.
Keywords: 552 imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) •
688 retina •
452 choroid