Abstract
Purpose: :
To compare the retinal thickness measurement and segmentation capabilities of different optical coherence tomography (OCT) devices for imaging eyes with cystoid macular edema (CME) associated with branch retinal vein occlusion (BRVO). Furthermore, to evaluate the relationship between morphological outcomes and macular sensitivity.
Methods: :
In this prospective, controlled, comparative, clinical study, 20 eyes of 20 patients with acute BRVO were included. The healthy partner eyes served as control group. Retinal thickness was measured using time domain (Stratus OCT) and spectral domain (Cirrus OCT, Spectralis OCT) OCT technologies and macular sensitivity was examined using microperimetry (Nidek MP1).
Results: :
In both groups, Stratus OCT showed the lowest retinal thickness measurements, Cirrus OCT ranged in between, and Spectralis OCT showed the highest thickness measurements. With regard to mean value in the central 1mm, mean difference of 31 µm, 92 µm, and 75 µm was found between Stratus OCT and Cirrus OCT, Stratus OCT and Spectralis OCT as well as between Cirrus OCT and Spectralis OCT, respectively (p=0.11, p<0.001, p=0.02, resp.). Compared to the control group, thickness measurement in eyes with BRVO showed a lower correlation between the different OCT devices, with exception of Stratus OCT, which correlated well with Spectralis OCT (Pearson r= 0.85, p < 0.001). 8.9% of the segmentation analyses had moderate and severe errors with Spectralis OCT, 12.4% with Stratus OCT and 36.5% with Cirrus OCT. Mean macular sensitivity was 6.2±3.7 db and 10.7±4.2 db in BRVO area versus non affected area, respectively (p<0.001). Mean macular sensitivity was 4.6±3.3 db in the central 1mm area. Absolute scotoma detected by microperimetry averaged 17.6%. No correlation was found between macular sensitivity and retinal thickness in central 1 mm area (Pearson r<0.28, p>0.05).
Conclusions: :
The examination results of the three different OCT devices are not comparable when imaging eyes with BRVO. Spectral domain OCT provides more detailed imaging and more precise detection and visualization of intraretinal structures due to a novel technology. Nevertheless, spectral domain Cirrus OCT showed remarkably more alignment artefacts than time domain Stratus OCT in BRVO eyes. Accurate thickness measurement without segmentation errors is rather a matter of segmentation software than of OCT technology.
Keywords: vascular occlusion/vascular occlusive disease • imaging/image analysis: clinical • perception