Comparison of neovascularization (NV) detection in proliferative diabetic retinopathy (PDR) between single-capture wide-field optical coherence tomography angiography (WF-OCTA) and ultra-widefield fluorescein angiography (UWF-FA)

Abstract

Purpose : To compare the detection rate of retinal NVs in eyes with PDR between UWF-FA and WF-OCTA systems.

Methods : In this ongoing prospective study patients with NV at the disc (NVD) or elsewhere (NVE) detected on UWF-FA (California, Optos) were recruited from our outpatient clinic. Single-capture 65° (18x18 mm) WF-OCTA-imaging was performed using a Zeiss PLEX Elite prototype (Carl Zeiss Meditec GmbH) at an A-scan rate of 1.7 mHZ; and an axial and lateral resolution of 9 µm and 20 µm, respectively. Angiograms were visually enhanced using a deep learning-based algorithm for denoising. WF-OCTA B-scans were examined for blood flow signals above the internal limiting membrane by two retina specialists.

Results : 38 eyes of 26 patients with PDR detected on UWF-FA were included until December 2021. 36 eyes (94.7%) had at least one NV within the 18x18mm WF-OCTA. A total of 141 NVEs were detected on UWF-FA of which 41 (29.1%), 50 (35.5%), 28 (19.9%), and 22 (15.6%) were located superotemporal, inferotemporal, superonasal, and inferonasal, respectively. Significantly more NVEs occurred in the temporal compared to the nasal quadrants (p < 0.05). 87 NVEs (61.7% of all NVEs) were detected using single-capture WF-OCTA. Compared to UWF-FA the number of NVEs detected on WF-OCTA in the superotemporal, inferotemporal, superonasal, and inferonasal quadrants was 35 (85.4%), 40 (80%), 5 (17.9%), and 7 (31.8%), respectively.

Conclusions : Single-capture WF-OCTA allows correct classification of PDR in 95% of individuals by detecting at least one NV within the observed field. On UWF-FA NVEs were most prevalent in the temporal fields with a majority of them detected on WF-OCTA scans. Quick and non-invasive WF-OCTA imaging has the potential to replace FA as a single diagnostic tool in clinical routine in the evaluation of PDR activity.

This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.

 

(A) Single-capture WF-OCTA with dashed line corresponding to the B-scan in (B). (B) B-scan showing a disruption and flow above the internal limiting membrane representing diabetic NV. (C) UWF-FA shows areas of NV as hyperfluorescent leakage. The white circle corresponds to the 18x18mm field of view seen with single-capture WF-OCTA. The yellow lines divide the UWF-FA image into four quadrants: superotemporal, inferotemporal, superonasal, inferonasal.