A two-year longitudinal study of retinal vascular impairment in patients with amnestic mild cognitive impairment

Abstract

ObjectiveTo evaluate the relation between retinal vascular impairment and cognitive decline in patients with amnestic mild cognitive impairment (aMCI) over time.MethodsSpectral domain-optical coherence tomography (SD-OCT) and OCT angiography study was performed in aMCI patients over 2 years follow-up and compared to baseline.ResultsThirty-eight eyes from 19 aMCI patients were evaluated. Structural and vascular OCT measures were reduced at follow-up except for vessel density (VD) of the choriocapillaris, unchanged, and foveal avascular zone, which was increased; no changes in any parameter were found in 18 age-matched healthy controls. Overall, these findings were confirmed when patients were evaluated separately according to progression to dementia. Only non-converters to dementia showed significant VD reduction in the deep capillary plexuses (coeff. β = −4.20; p < 0.001), may be for an initial massive VD depletion becoming less evident with progression of the disease. MMSE reduction was associated with a higher ganglion cell complex reduction (coeff. β = 0.10; p = 0.04) and a higher VD reduction in the radial peripapillary capillary (RPC) plexus (coeff. β = 0.14; p = 0.02) in the whole patient group, while it was associated with a higher VD reduction only in RPC plexus in converters (coeff. β = 0.21; p < 0.001).ConclusionOur data shows vascular impairment progression in the inner retina of aMCI patients and support the hypothesis that vascular changes may contribute to the onset and progression of Alzheimer’s disease. Other follow-up studies, with a larger number of patients, are needed to better define VD as a potential biomarker.

A Systematic Review on Retinal Biomarkers to Diagnose Dementia from OCT/OCTA Images

“…However, there was no statistically significant change seen at follow-up (p > 0.05) for the annual FAZ parameter. A longitudinal research for the course of 2 years in [35] studied OCT parameters (pRNFL, GCC thicknesses) and OCTA parameters (FAZ area, VD of SCP, DCP, CC, and RPC) changes at baseline and after follow-up for aMCI and HCs. The cohort of 18 HCs and 19 aMCI patients were split into 12 stable aMCI (aMCI Stable ) patients and 7 aMCI patients converted to (AD-type) dementia (aMCI Converted ).…”

“…Conversely, the VD of CC reduced but did not reach statistical significance between aMCI at baseline and at follow-up. Furthermore, [35] performed a comparison between aMCI Converted and aMCI Stable in terms of altered OCT/OCTA parameters. They found out that GCC and pRNFL thicknesses were significantly reduced for both aMCI Converted and aMCI Stable subcategories.…”

“…Some research works use the commercial software which accompanies the OCT/OCTA machine. For instance, both [19,35] extracted OCT and OCTA parameters automatically by a commercial RTVue XR software and Optovue AngioVue system (software ReVue XR). In addition, the AngioAnalytics™ software was used by [36] to compute VD and FD for retinal vasculature as well as the perimeter and Acircularity Index for FAZ.…”

Clearance of interstitial fluid (ISF) and CSF (CLIC) group‐part of Vascular Professional Interest Area (PIA), updates in 2022‐2023. Cerebrovascular disease and the failure of elimination of Amyloid‐β from the brain and retina with age and Alzheimer's disease: Opportunities for therapy

“…Prior reports demonstrated that retinal vascular abnormalities may be used as biomarkers of early or preclinical dementia, and retinal microvascular changes in MCI and dementia have been described applying various retinal vasculature imaging modalities, including optical coherence tomography angiography, retinal fundus photography, high‐frequency flicker‐light stimulation, and the retinal function imager 77,79,124,131–136 . Histologically, a wide range of vascular changes has been described in the retina of MCI and AD patients 77,101,102,137 .…”

“…Prior reports demonstrated that retinal vascular abnormalities may be used as biomarkers of early or preclinical dementia, and retinal microvascular changes in MCI and dementia have been described applying various retinal vasculature imaging modalities, including optical coherence tomography angiography, retinal fundus photography, high‐frequency flicker‐light stimulation, and the retinal function imager. 77 , 79 , 124 , 131 , 132 , 133 , 134 , 135 , 136 Histologically, a wide range of vascular changes has been described in the retina of MCI and AD patients. 77 , 101 , 102 , 137 These changes include perivascular and vascular Aβ 40 and Aβ 42 accumulations associated with pericyte and capillary loss and tight junction damage.…”