Evaluation of ocular perfusion in Alzheimer’s Disease using optical coherence tomography angiography

Abstract

Purpose : To evaluate retinal and optic nerve head (ONH) perfusion in patients with Alzheimer's disease (AD) using optical coherence tomography angiography (OCTA), and to analyse the correlations of quantitative OCTA metrics with Alzheimer pathology and vascular cerebral lesions in AD patients.

Methods : 36 eyes of 36 patients with AD (study group) and 38 eyes of 38 healthy subjects (control group) were prospectively included in this study. OCT-A was performed using RTVue XR Avanti with AngioVue. In addition, patients underwent a detailed ophthalmological and neurological examination including Mini Mental State Examination (MMSE), cerebral magnetic resonance imaging (MRI), and β amyloid (Aβ) and tau protein levels in the cerebrospinal fluid (CSF).

Results : The flow density in the superficial retinal OCT angiogram of the macula in the study group was significantly lower compared to the control group (p=0.001). There was a significant correlation between the flow density in the superficial retinal OCT angiogram of the macula, as measured using OCTA, and the Fazekas scale (Spearman’s correlation coefficient = -0.520; p=0.003). There was no significant correlation between the β amyloid or tau protein levels in the CSF and the flow density data.

Conclusions : Patients with AD showed a reduced flow density in the radial peripapillary capillaries (RPC) layer and in the superficial retinal OCT angiogram when compared with healthy controls. The reduced retinal flow density measured using OCTA is not specifically associated with Alzheimer pathology but is associated with the vascular cerebral lesions in AD.

This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.