Abstract
Purpose :
To explore and characterize nonperfused capillaries (NPCs) in eyes with age-related macular degeneration (AMD) with a deep learning-based segmentation method for structural and angiographic optical coherence tomography (OCT).
Methods :
In this study, 3×3-mm macular OCT and OCT angiography (OCTA) scans with a 400×400 sampling density from 89 eyes of 80 participants (29 early, 16 intermediate, and 26 advanced AMD and 9 healthy controls) were obtained using a commercial 120-kHz spectral-domain OCT system (Solix; Visionix/Optovue, Inc., California, USA). Eight to twenty orthogonal scans (x-fast and y-fast) were registered and merged to obtain a high-definition volume. A projection-resolved OCTA algorithm was applied. Enface OCT/OCTA of deep capillary plexus (DCP) was generated by projecting the mean and maximum signals, respectively [Fig 1. (A, B, C)]. We used a deep learning-based denoising method to segment capillaries in enface OCT/OCTA [Fig 1. (D, E)]. Nonperfused capillaries were identified by comparing the structural and angiographic segmentations [Fig 1. (F, G)]. The Mann-Whitney U-test was applied to compare the number and the total length of NPCs in 18 healthy and 71 eyes with AMD. Univariate logistic regression analysis assessed the relationship between NPCs and the presence of geographic atrophy (GA), choroidal neovascularization (CNV), and retinal fluid, and an odds ratio (OR) was computed. We used Pearson correlation to quantify the association of NPCs with nonperfused area (NPA) and drusen volume in eyes with AMD [Fig 2].
Results :
Compared to healthy eyes, the number and total length of NPCs in eyes with AMD was significantly increased (2.7±1.7 vs. 7.8±8.5, P=0.001; 0.5±0.3 mm vs. 3.3±3.2 mm, P<0.001, Mann-Whitney U-test). In eyes with AMD, the presence of GA (19/52) and CNV (13/58), and NPA significantly correlated with the number (OR=1.215, P=0.003; OR=1.070, P=0.030, univariate logistic regression; R=0.437, P<0.001, Pearson correlation) and total length (OR=1.920, P=0.004; OR=1.176, P=0.044; R=0.462, P<0.001) of NPCs; however, the presence of retinal fluid (17/54) and drusen volume were unrelated to the number (OR=1.001, P=0.972; R=0.184, P=0.125) and total length (OR=1.029, P=0.720; R=0.134, P=0.180).
Conclusions :
The number and total length of NPCs in the DCP are greater in eyes with AMD compared to normal eyes, and among eyes with AMD, they are greater in eyes with GA and CNV.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.