Journal Article

Changes in visual function and retinal structure in the progression of Alzheimer's disease

López-Cuenca, Inés, Vazirani, Ravi, de Hoz, Rosa, Rojas, Pilar, Pinazo-Durán, María D., Ramírez, José M., Yubero, Raquel, Salobrar-García, Elena, Amarante, Carla, Gil, Pedro, Ramírez, Ana I., Salazar, Juan J.

2019

Overview

Alzheimer's Disease (AD) can cause degeneration in the retina and optic nerve either directly, as a result of amyloid beta deposits, or secondarily, as a result of the degradation of the visual cortex. These effects raise the possibility that tracking ophthalmologic changes in the retina can be used to assess neurodegeneration in AD. This study aimed to detect retinal changes and associated functional changes in three groups of patients consisting of AD patients with mild disease, AD patients with moderate disease and healthy controls by using non-invasive psychophysical ophthalmological tests and optical coherence tomography (OCT). We included 39 patients with mild AD, 21 patients with moderate AD and 40 age-matched healthy controls. Both patients and controls were ophthalmologically healthy. Visual acuity, contrast sensitivity, colour perception, visual integration, and choroidal thicknesses were measured. In addition, OCT and OCT angiography (OCTA) were applied. Visual acuity, contrast sensitivity, colour perception, and visual integration were significantly lower in AD patients than in healthy controls. Compared to healthy controls, macular thinning in the central region was significant in the mild AD patients, while macular thickening in the central region was found in the moderate AD group. The analysis of macular layers revealed significant thinning of the retinal nerve fibre layer, the ganglion cell layer and the outer plexiform layer in AD patients relative to controls. Conversely, significant thickening was observed in the outer nuclear layer of the patients. However, mild AD was associated with significant thinning of the subfovea and the nasal and inferior sectors of the choroid. Significant superonasal and inferotemporal peripapillary thinning was observed in patients with moderate disease. The first changes in the mild AD patients appear in the psychophysical tests and in the central macula with a decrease in the central retinal thickness. When there was a disease progression to moderate AD, psychophysical tests remained stable with respect to the decrease in mild AD, but significant thinning in the peripapillary retina and thickening in the central retina appeared. The presence of AD is best indicated based on contrast sensitivity.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Acuity / Advertising executives / Age / Alzheimer Disease - diagnostic imaging / Alzheimer Disease - pathology / Alzheimer Disease - physiopathology / Alzheimer's disease / Angiography / Biology and Life Sciences / Change detection / Color / Color Perception - physiology / Color sensitivity / Contrast Sensitivity - physiology / Cortex (inferotemporal) / Degeneration / Dementia / Development and progression / Diagnosis / Diagnostic imaging / Disease control / Disease Progression / Epidemiology / Evaluation / Expulsions & suspensions / Ganglion cysts / Hospitals / Humans / Integration / Medicine and Health Sciences / Memory / Mental disorders / Nervous system / Neurodegeneration / Neurodegenerative diseases / Ophthalmology / Optic nerve / Optical Coherence Tomography / Physiological aspects / Prime ministers / Proteins / Psychophysics / Research and Analysis Methods / Retina / Retina - diagnostic imaging / Retina - pathology / Retina - physiopathology / Sensitivity / Social Sciences / Structure-function relationships / Thickening / Thickness measurement / Thinning / Tomography / Tomography, Optical Coherence / Vision, Ocular - physiology / Visual acuity / Visual Acuity - physiology / Visual cortex / Visual effects / Visual perception