Quality and Reproducibility of Retinal Thickness Measurements in Two Spectral-Domain Optical Coherence Tomography Machines

Abstract

Considerable differences were found between the two systems, both of which incorporate the spectral-domain technology. Different positioning of segmentation lines, control of localization, density of included scan lines, and number of available maps explain the differences in segmentation quality and reproducibility. Manual correction of segmentation and centralization improves the reproducibility.

Identifying the Boundaries of Retinal Pigment Epithelial Detachments Using Two Spectral-Domain Optical Coherence Tomography Instruments

“…Krebs et al also reported greater retinal thickness with the Spectralis instrument (370.9 ± 105.4 µm) compared with the Cirrus instrument (271 ± 87.3 µm) in wet AMD patients. 13 In this study, the posterior line was positioned along Bruch's membrane in 84.4% of PED patients. Moreover, in 44.4% of those cases, identification of the posterior boundary failed, following partially both Bruch's membrane and RPE.…”

“…The Spectralis OCT typically segmented the back edge of the same hyper-reflective band, leading to somewhat thicker retinal thickness measurements. 13 However, the Spectralis algorithm failed to properly segment the central B-scan in 25 eyes (92.6%). In 20 of these eyes, the algorithm followed Bruch's membrane instead of the RPE (Fig.…”

“…Moreover, in 44.4% of those cases, identification of the posterior boundary failed, following partially both Bruch's membrane and RPE. 13 In principle, the choice of acquisition protocol can influence the performance of the segmentation algorithms. In particular, the Cirrus SD-OCT uses a three-dimensional algorithm that can be affected by the geometry of the sampling grid.…”

“…Several papers have recently analyzed various characteristics of these segmentation algorithms,7,8 particularly their reproducibility in a number of different conditions. [9][10][11][12][13][14][15][16] The presence of a PED can present a challenge for a segmentation algorithm due to the deformation of the RPE. 8,17 Accurate identification of the RPE layer is required to obtain an accurate retinal thickness measurement in the setting of PEDs.…”

“…8,17 Accurate identification of the RPE layer is required to obtain an accurate retinal thickness measurement in the setting of PEDs. 13,18 The impor-…”