Retinal vessel density and cognitive function in healthy older adults.

Area of Science:

• Ophthalmology
• Neuroscience
• Gerontology

Background:

• The retina offers a unique, non-invasive window into brain health due to its central nervous system tissue.
• Retinal blood flow is explored as a potential biomarker for cognitive decline, with existing data being contradictory in healthy older adults.

Purpose of the Study:

• To investigate the correlation between Optical Coherence Tomography Angiography (OCTA) parameters and executive functions (EFs) in healthy older adults.
• To examine the mediating role of hematocrit in the relationship between retinal microcirculation and cognitive performance.

Main Methods:

• Utilized OCTA to assess retinal microcirculation, specifically vessel density (VD) in the superficial vascular complex.
• Employed structural equation modeling to analyze the relationship between OCTA parameters, hematocrit, and EFs (inhibition, updating, shifting).

Main Results:

• The study found no significant direct or indirect correlation between retinal vessel density and executive functions.
• Hematocrit emerged as a significant mediator, correlating with executive function performance, particularly the 'updating' task.
• Regression analysis indicated that higher hematocrit levels are associated with faster reaction times and increased coefficient of variation, suggesting a positive effect on EFs.

Conclusions:

• Hematocrit, rather than retinal microcirculation, appears to be a key factor influencing executive functions in healthy older adults.
• Findings suggest a potential role for hematocrit monitoring in understanding cognitive performance and decline in aging populations.