Visual dysfunction and its correlation with retinal changes in patients with Alzheimer's disease

Area of Science:

• Ophthalmology
• Neurology
• Medical Imaging

Background:

• Alzheimer's disease (AD) is a neurodegenerative disorder.
• Visual dysfunction is increasingly recognized in AD patients.
• Retinal structural changes may precede or accompany AD-related brain pathology.

Purpose of the Study:

• To investigate visual dysfunction in Alzheimer's disease (AD).
• To correlate visual function with retinal structural changes in AD patients.
• To assess the utility of optical coherence tomography (OCT) in evaluating AD-related ocular changes.

Main Methods:

• Patients with AD (n=24) and controls (n=24) underwent visual acuity, color vision, and contrast sensitivity vision (CSV) testing.
• Spectral domain-optical coherence tomography (SD-OCT) was used to measure retinal nerve fiber layer (RNFL) thickness and macular thickness.
• Statistical analyses were performed to correlate functional visual parameters with structural retinal measurements.

Main Results:

• AD patients exhibited significantly worse CSV at multiple spatial frequencies compared to controls.
• Color vision was significantly impaired in AD patients.
• Macular thinning was observed in all sectors except the fovea, and significant RNFL thinning was noted in the superior quadrant.
• CSV showed the strongest correlation with structural retinal measurements in AD patients.
• Color vision was strongly associated with macular volume, and visual acuity correlated with macular and RNFL thickness.

Conclusions:

• Visual dysfunction, including impaired contrast sensitivity and color vision, is present in Alzheimer's disease.
• Structural changes in the retina, such as macular thinning and RNFL reduction, are correlated with visual dysfunction in AD.
• Macular measurements derived from SD-OCT may serve as reliable indicators of visual impairment in AD patients.