Retinal microvascular network attenuation in Alzheimer's disease

Area of Science:

• Ophthalmology
• Neurology
• Vascular Biology

Background:

• Cerebral small-vessel disease is implicated in Alzheimer's disease (AD) pathogenesis.
• The retinal microvasculature offers a noninvasive window into systemic microcirculation.
• Evaluating retinal microvascular parameters can provide insights into AD-related vascular changes.

Purpose of the Study:

• To investigate the association between retinal microvascular parameters and Alzheimer's disease.
• To compare retinal microvascular characteristics in AD patients versus cognitively normal controls.

Main Methods:

• A case-control study design was employed.
• Retinal images were computationally analyzed to measure parameters like caliber, fractal dimension, tortuosity, and bifurcation.
• Regression models were used to calculate odds ratios (OR) and confidence intervals (CI) for AD, adjusting for confounders.

Main Results:

• The study included 213 AD participants and 294 cognitively normal controls.
• Lower venular fractal dimension (OR per SD increase: 0.77) and lower arteriolar tortuosity (OR per SD increase: 0.78) were significantly associated with increased odds of AD.
• These associations remained significant after adjusting for potential confounders.

Conclusions:

• Patients with Alzheimer's disease exhibit a sparser retinal microvascular network.
• Alterations in retinal microvasculature may reflect similar pathological processes occurring in the cerebral microvasculature of AD patients.
• Retinal microvascular parameters could serve as potential biomarkers for AD.