Aging-Related Choroidal Heterogeneity and Loss: An Investigative Global Human Choroidal Thickness Review (ARCHLIGHT...

Area of Science:

• Ophthalmology
• Gerontology
• Neuroscience

Background:

• Choroidal thickness naturally declines with aging.
• This age-related thinning has significant clinical implications for ocular and systemic health.
• Understanding these changes is crucial for diagnosing and managing various pathologies.

Purpose of the Study:

• To synthesize current evidence on the pathophysiology of age-related choroidal thinning.
• To evaluate the clinical relevance and implications of choroidal thinning in aging populations.
• To establish the link between choroidal thinning and retinal/neurodegenerative diseases.

Main Methods:

• Systematic literature search across major databases (MEDLINE, Embase, Cochrane Library) up to May 2024.
• Analysis of studies reporting choroidal thickness changes with aging.
• Inclusion of data on subfoveal choroidal thickness, choroidal vascularity index, and influencing factors like ethnicity and systemic disease.

Main Results:

• Choroidal thickness decreases with age, with ethnicity-specific rates (e.g., -0.93 µm/year in Spanish to -4.00 µm/year in Chinese populations).
• Thinning correlates with glaucoma, myopic maculopathy, and Alzheimer disease, with specific thickness values noted for each.
• Optical coherence tomography (OCT) reveals vascular loss (choroidal vascularity index <30%) and stromal atrophy; systemic factors like hypertension accelerate thinning.

Conclusions:

• Age-related choroidal thinning represents a spectrum from normal aging to pathology, impacting retinal and systemic health.
• Future studies should define diagnostic thresholds (e.g., subfoveal choroidal thickness <200 µm in adults >60 years) and management strategies.
• Therapeutic monitoring of choroidal thickness changes is recommended for high-risk groups, based on moderate- to low-certainty evidence.