Association Between Retinal Layer Thickness and Cognitive Decline in Older Adults

Area of Science:

• Ophthalmology
• Neurology
• Gerontology

Background:

• Retinal layer thickness is a potential indicator for cognitive function in mild cognitive impairment (MCI) and Alzheimer's disease (AD).
• Longitudinal studies in healthy older populations are limited, necessitating further investigation.

Purpose of the Study:

• To examine the relationship between retinal layer thickness and cognitive impairment.
• To assess the association between retinal layer thickness and future cognitive decline in a community-based cohort.

Main Methods:

• A cohort of 430 Korean adults aged 60+ underwent baseline assessment and follow-up for approximately 5.4 years.
• Spectral-domain optical coherence tomography was used to measure the thickness of retinal layers, including macular RNFL and subfoveal choroid.
• Cognitive function was assessed using CERAD and MMSE scores, with adjustments for age, sex, education, diabetes, hypertension, and APOE4 status.

Main Results:

• Baseline macular RNFL thickness correlated with baseline CERAD and MMSE scores.
• A thinner baseline macular RNFL thickness (lowest quartile) was significantly associated with a greater decline in CERAD and MMSE scores over time.
• Individuals with the thinnest macular RNFL had a higher prevalence of cognitive impairment and AD compared to those with thicker RNFL.

Conclusions:

• Macular RNFL thickness can serve as a prognostic biomarker for long-term cognitive decline in individuals aged 60 and older.
• Further large-scale, population-based studies are recommended to validate these findings.