Ocular Exploration in the Diagnosis and Follow-Up of the Alzheimer’s Dementia

ABSTRACT The retina is part of the central nervous system (CNS), and therefore, in Alzheimer’s disease (AD), retinal and optic nerve degeneration could take place. This degeneration leads to neurofunctional changes that can be detected early and followed up throughout the evolution of the disease. As opposed to other CNS structures, the eye is easily accessible for in vivo observation. Retinal organization allows for the identification of its different neurons, and in consequence, detection of minimal changes taking place during neurodegeneration is possible. Functional vision studies performed on AD patients in recent years have shown how visual acuity, contrast sensitivity, color vision, and visual integration vary with the progression of neurodegeneration. The development of optical coherence tomography in ophthalmology has meant a breakthrough in retinal exploratory techniques, allowing the obtention of high-resolution images using light. This technique enables retinal analysis in the earliest stages of AD, being considered as a biomarker of neuronal damage. Given AD’s high prevalence and its expected increase, it is important to perform easy tests that cause minimal discomfort to the patients at a low cost while offering abundant information on the stage of the disease.