Abstract
Purpose :
The retina is a promising window into understanding Alzheimer’s disease pathology. Structural changes are seen in the retinal nerve fiber layer (RNFL) layer as well as optic nerve degeneration, choroidal thickening, and amyloid-beta plaque accumulation in retinal vasculature. This study investigates fluorescence lifetime imaging ophthalmoscopy (FLIO) and other multimodal retinal imaging in patients with Alzheimer’s disease pathology.
Methods :
11 eyes from 7 patients (mean age 81 years) were included in this cross-sectional study. All patients underwent Heidelberg Engineering FLIO imaging, High-Resolution (HR-OCT) OCT and OCT Angiography (OCTA) scans, and Spectralis multispectral, retinal nerve fiber layer (RNFL), and macular pigment measurements (dual-wavelength autofluorescence). Autofluorescence lifetimes (30° retinal field) were obtained in two spectral channels (SSC: 498-560 nm; LSC: 560-720 nm), and amplitude-weighted mean fluorescence lifetimes (tm) were analyzed.
Results :
Mild cognitive impairment (MCI) and Alzheimer’s disease (AD) eyes showed a significant prolongation of FLIO lifetimes in the central region (CR) of the standardized Early Treatment Diabetic Retinopathy Study (ETDRS) grid of the SSC compared to healthy eyes (p = 0.0073). OCTA images from the inner and outer plexiform layers in AD patients only showed larger foveal avascular zones and less retinal perfusion compared to healthy eyes.
Conclusions :
Longer FLIO lifetimes in the CR of the ETDRS grid may suggest a reduction of macular pigment in the fovea of patients with Alzheimer’s disease pathology. FLIO and other multimodal imaging modalities (OCT and OCTA) may serve as non-invasive tools to detect, monitor, and understand disease pathophysiology in MCI and AD patients.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.