A Novel Method to Achieve Comparability Between Spectral-Domain and Time-Domain Optical Coherence Tomography Measurement
The quantitative assessment of retinal thickness and volume varies according to the optical coherence tomography (OCT) machine used due to differences in segmentation lines. We describe a novel method of adjusting the segmentation lines of spectral-domain OCT (SD-OCT) to enable comparison with time-domain OCT (TD-OCT).
Summary of Content
In a prospective study, SD-OCT (Spectralis OCT) and TD-OCT (Stratus OCT) were sequentially performed on 200 eyes of 100 healthy individuals. Central retinal thickness (CRT), central point thickness (CPT), and 1-mm volume of the Early Treatment Diabetic Retinopathy Study grid were compared between the two machines. The segmentation lines on SD-OCT were manually adjusted by a trained operator and the parameters compared again with TD-OCT. The mean CRTs of Spectralis and Stratus were significantly different (266.6 μm vs. 192.2 μ m, P < 0.001). After adjustment of segmentation lines, the mean adjusted Spectralis CRT was 198.0 μm, with the difference between SDOCT and TD-OCT measurements decreasing from 74.4 μ m to 3.8 μ m (P < 0.001). Similar trends were obtained for central 1-mm volumes and CPT. Interoperator and intraoperator repeatability for adjustment of the segmentation lines were good, with an intraclass correlation of 0.99 for both. Manual adjustment of SD-OCT segmentation lines reliably achieves retinal thickness and volume measurements that are comparable to that of TD-OCT. This is valuable to allow comparisons in multicenter clinical trials where different OCT machines may be used.
[ Keyword ]
Optical Coherence Tomography
[ Conflict of Interest ]