Retinal microvasculature and choriocapillaris impairments according to the stage of dry age‐related macular degeneration

Abstract

Background: We aimed to analyse the retinal microvasculature and choriocapillaris according to the dry age-related macular degeneration (AMD) stage and to identify factors associated with their microvasculatures. Methods: Patients were divided into four groups: normal controls, early, intermediate and advanced AMD groups. The vessel density (VD) of superficial capillary plexus (SCP), deep capillary plexus (DCP) and choriocapillaris was compared using optical coherence tomography angiography among the groups.Linear regression analysis was performed to identify factors associated with the VD. Results:The VDs of the SCP were 22.1 ± 5.7, 19.1 ± 5.4, 18.0 ± 6.4 and 12.2 ± 6.4% (p < 0.001); the VDs of the DCP were 22.4 ± 4.5, 20.7 ± 4.3, 18.1 ± 5.3 and 14.6 ± 5.8% (p < 0.001); the VDs of the choriocapillaris were 29.4 ± 3.7, 26.4 ± 4.8, 24.5 ± 4.9 and 24.2 ± 3.7% (p < 0.001) in the control, early, intermediate, and advanced groups, respectively. AMD stage and age were significantly associated with the VDs of all layers, and the VDs of the SCP and DCP were associated with visual acuity (both p < 0.001). Additionally, hypertension was associated with the VDs of the DCP (p = 0.027) and choriocapillaris (p = 0.024). Conclusions: The retinal microvasculature and choriocapillaris tended to become more impaired as the AMD stage progressed. Age was significantly associated with the microvasculature impairments of all layers, and hypertension was significantly associated with impairments of the DCP microvasculature and choriocapillaris.

Superficial capillary plexus vessel density/deep capillary plexus vessel density ratio in healthy eyes

“…The VD was calculated as the percentage area occupied by blood vessels, with the blood vessels being defined as pixels having decorrelation values above the threshold level using ImageJ software (National Institutes of Health, Bethesda, MD, USA ) [8,9]. After setting images with 8-bit type, the adjusted threshold tool was applied with default settings, and the dark background option was selected as a previous study [10]. This tool automatically sets the lower and upper threshold values (arbitrarily chosen as 110 and 255, respectively, for every image) and segmented grayscale images into features of interest and background (Fig.…”

Spotlighting retinal diseases

“…In a study involving spectral domain‐optical coherence tomography (SD‐OCT) to predict prognosis, Cheong et al 8 showed a relatively large variation in central macular thickness (over 67 μm, or the upper tertile in the study cohort of 141 eyes) was associated with a worse visual acuity (VA) outcome for patients being treated for neovascular AMD with intravitreal anti‐vascular endothelial growth factor (VEGF) therapy. Kim et al 9 used OCT‐angiography across 194 eyes to demonstrate an association between dry AMD and reduced vascular density in the retinal and choroidal microcirculations. This reduction was significantly associated with hypertension, stressing the importance of addressing this systemic disease in patients with AMD.…”