Abstract
Purpose :
To evaluate the existence, in diabetic subjects, of a relationship between the radial peripapillary capillary plexus (RPCP) and the superficial vascular (SVP) and deep capillary plexuses (DCP) in mid-peripheral retina, using widefield optical coherence tomography angiography (WF OCTA).
Methods :
Patients affected by diabetes mellitus with mild nonproliferative diabetic retinopathy were enrolled. An age-matched healthy population was used as control. Each subject underwent a full ophthalmologic evaluation, including OCTA, using a swept source WF OCTA (PLEX Elite 9000 Carl Zeiss Meditec Inc., Dublin, CA, USA) with scans centered on the optic nerve head and on four standardized peripheral regions of interest (ROIs): superior, inferior, temporal, nasal. The quantification of capillary parameters included: vessel area density (VAD), vessel diameter index (VDI), vessel length fraction (VLF) of the RPCP, and of SVP and DCP in retina mid-periphery. The correlation between vascular parameters of the RPCP and both mid-peripheral capillary plexuses was investigated.
Results :
One hundred ninety-six eyes from 113 diabetic patients and 107 eyes from 58 healthy subjects were recruited. A positive and direct correlation was found between VAD, VLF and VDI of RPCP and the same indexes of the peripheral DCP (CC=0.60, CC=0.43 and CC=0.44, respectively), considering the average of the peripheral measurements in the four ROIs About DCP, a positive correlation was also found between VAD of the RPCP and VAD of all single peripheral ROIs (CC=0.61, CC=0.47, CC=0.44 and CC=0.53, for superior, inferior, temporal e nasal ROI, respectively). No correlation was found between the RPCP OCTA parameters versus SVP parameters. No significant correlation was found between RPCP, and DCP and SVP OCTA parameters in the control group.
Conclusions :
WF OCTA demonstrates that in diabetic patients, but not in normal ones, the vascular characteristics of the RPCP mirror the same parameters of mid-peripheral DCP, in all examined regions. This study reveals that RPCP and DCP, but not SVP, have the same behavior in diabetic subjects, and the evaluation of RPCP, less influenced and limited by confounding factors, may represent the key for the analysis of peripheral retinal vasculature in diabetic subjects, for both diagnostic and prognostic purposes.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.