Abstract
Purpose :
To analyze the quality and prevalence of image artifacts and segmentation errors in widefield swept source optic tomography angiography (SS-OCTA) in diabetic retinopathy (DR).
Methods :
We conducted a prospective, observational study in Mass Eye and Ear from December 2018 to February 2019. Proliferative diabetic retinopathy (PDR), non-proliferative diabetic retinopathy (NPDR), diabetic patients with no DR and healthy eyes with no ocular diseases were included. All patients were imaged with an SS-OCTA (PLEX® Elite 9000) in active eye tracking and the montage image composed of two 15mm*9mm angio-image (superior and inferior) was used for analysis. Best-corrected visual acuity (BCVA, LogMAR) and signal strength index (SSI) were recorded. Images were independently evaluated by two graders using the OCT-A motion artifact score (MAS; score I-IV) and segmentation accuracy score (SAS; Sore I-IIB) after automatically removing projection. All statistic analyses were performed using SAS ® software.
Results :
Seventy-two eyes (30 eyes with PDR, 19 eyes NPDR, 13 eyes of no DR and 10 healthy eyes) were included in the study. The average age of the participants was 56.08±4.06 years, and there was no significant difference among the 4 groups (P=0.68). Compared with the superior part(8.64±0.20), mean SSI in inferior (8.52±0.20) was significantly lower (P<0.05). In addition mean MAS was 0.83±0.12 and 0.97±0.16 in superior and inferior part, respectively. Segmentation was accurate in health (100%), no DR eyes (92.3%) and NPDR (78.95%). Segmentation errors were mostly observed in DR patients with neovascularization (NV), diabetic macular edema (DME) and epiretinal membrane (EM). Furthermore, the lowest MAS (1.2 ± 0.11) and highest percentage of inaccurate segmentation (60%) were found in inferior part in eyes with PDR. Media opacity in 18 eyes (24.0%), and in superior part (10 eyes, 55.56%). We also observed alignment error (22 eyes, 30.56%) and periphery artifacts (47 eyes,65.28%) in montage images.
Conclusions :
Motion artifacts and segmentation errors are frequent in eyes with PDR in wide-field OCTA. It is necessary to assess the motion artifacts and segmentation of montage image prior to get meaningful and reliable results, especially in DR patients with NV, DME and EM.
This abstract was presented at the 2019 ARVO Imaging in the Eye Conference, held in Vancouver, Canada, April 26-27, 2019.