Abstract
Purpose :
Recent analysis shows location-specific retinal vascular changes in intermediate age-related macular degeneration (iAMD) compared to normal eyes using optical coherence tomography angiography (OCTA): with vessel perfusion (VP) loss in the superficial and deep vascular complexes and potential sparing of the radial peripapillary capillary plexus (RPCP). This study examines if these retinal vascular changes exist in a more severe type of AMD: iAMD with reticular pseudodrusen (RPD).
Methods :
Single eyes from 90 individuals (30 with iAMD+RPD and 60 with iAMD) were propensity-score matched by age, signal strength intensity, sex, spherical equivalent refraction, and presence of cardiovascular disease such as hypertension. Automatically segmented superficial and deep vascular slabs were extracted for each eye from the 6x6mm OCTA scans (Zeiss Cirrus AngioPlex). Location-specific VP was then determined using a grid-wise approach (126x126 grid applied to 6x6mm scan, single grid area: ~47.62μm2) and compared between iAMD+RPD to iAMD eyes. Cluster analysis was performed to identify grid locations with statistically similar differences in VP.
Results :
In the superficial vascular complex, grid-wise VP differences could be grouped into three clusters (C-1, C0, and C+1). Cluster C+1 showed grid locations of significantly increased VP in eyes with RPD vs without (up to +2.54 [95% CI = +2.30 to +2.79] %, P < 0.0001) and were mostly located nasally (vs temporally; P = 0.004) and peripherally (vs central macula; P = 0.007). Cluster C-1 showed grid locations with decreased VP in eyes with RPD (up to -2.13 [95% CI = -2.42 to -1.83] %, P < 0.0001) and were diffusely distributed. The deep vascular complex showed similar cluster results to the superficial vascular complex, but there was no spatial bias.
Conclusions :
OCTA was used to characterize vascular changes in iAMD with RPD vs without, where we found a greater reduction in VP in eyes with RPD, suggesting more advanced disease. Areas of increased VP localised to the superficial vascular complex support potential sparing of the RPCP. Further evaluation of the inner retinal blood supply may aid in identifying the mechanism driving the development of RPD and associated pathogenesis of AMD.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.