Abstract
Purpose :
Optical coherence tomography angiography (OCTA) can image vascular changes such as microaneurysms (MA), vessel caliber, capillary non-perfusion and ischemia in diabetic retinopathy (DR). This study investigated the use of averaging to improve image quality and compared averaged to single images in detection of these entities using swept-source OCT (SS-OCT).
Methods :
DR patients were imaged with the PLEX® Elite 9000 (ZEISS, Dublin, CA) SS-OCT. Four to seven Angio 6x6 mm images were acquired on each patient. Single images were topographically analyzed using quality maps and the better quality repetition was chosen as a reference for registration. Averaged images were created by volumetrically registering the remaining frames to the reference image. Vascular abnormalities were identified in both the single and averaged images for each eye.
Results :
Fourteen eyes of 12 patients with DR of varying severity were included in this study. With few exceptions, the same vascular abnormalities were found in both the single and image-averaged scans (Table 1). One eye showed MAs and one had a better-defined area of non-perfusion in the image-averaged scan. The image quality of the small blood vessels was superior with the averaged scans, particularly in the deep vessel layer (Figure 1).
Conclusions :
In this study, most DR vascular abnormalities were recognized with both single and image-averaged scans. Image quality was found to be improved with averaging, but did not make a significant difference in identification of abnormalities. Both the superficial and deep vascular layers were enhanced with the image-averaged scans.
This abstract was presented at the 2019 ARVO Imaging in the Eye Conference, held in Vancouver, Canada, April 26-27, 2019.