Recent Developments of Retinal Image Analysis in Alzheimer’s Disease and Potential AI Applications

Alzheimers disease (AD) is the most common progressive neurodegenerative illness and cause of dementia in the elderly. The critical barriers for primary prevention in AD are the lack of rapid, non-invasive, sensitive and low-cost biomarkers. As the eye and brain share essential structural and pathogenic pathways, non-invasive eye biomarkers could be identified to obtain new insights into the onset and progression of AD and its complications in the eye. In this short review, recent developments of retinal image analysis in AD and potential artificial intelligence (AI) applications are presented. Some approaches are still very much novel research techniques, others are more established and transitioning into the clinical diagnostic arena. Together they provide us with the capability to move AD detection research forwards by using novel peripheral biomarkers

Oxygen saturation measurements of the retinal vasculature in treated asymmetrical primary open-angle glaucoma using hyperspectral imaging

Purpose: To determine whether there are differences in retinal vascular oxygen saturation measurements, estimated using a hyperspectral fundus camera, between normal eyes and treated eyes of subjects with asymmetrical primary open-angle glaucoma (POAG). Methods: A noninvasive hyperspectral fundus camera was used to acquire spectral images of the retina at wavelengths between 556 and 650 nm in 2-nm increments. In total, 14 normal eyes and both eyes of 11 treated POAG subjects were imaged and analyzed using algorithms that use the spectral variation of the optical densities of blood vessels to estimate the oxygen saturation of blood within the retinal vasculature. In the treated POAG group, each of the eyes were categorized, based on the mean deviation of the Humphrey visual-field analyzer result, as either more-advanced or less-advanced, glaucomatous eyes. Unpaired t-tests (two-tailed) with Welch’s correction were used to compare the mean oxygen saturation between the normal subjects and the treated POAG subgroups. Results: In less-advanced and more-advanced-treated POAG eyes, mean retinal venular oxygen saturations (48.2±21.6% and 42.6±18.8%, respectively) were significantly higher than in normal eyes (27.9±9.9%; P=0.03 and 0.01, respectively). Arteriolar oxygen saturation was not significantly different between normal eyes and treated POAG eyes. Conclusions: The increased oxygen saturation of the retinal venules in advanced-treated POAG eyes may indicate reduced metabolic consumption of oxygen in the inner retinal tissues