🩸 Retinal Imaging Alzheimer's Biomarker Simulator

The Retina as a Window into the Brain

Placeholder: retina shares developmental origin and pathology with the brain.

• Neural: Tissue origin (Placeholder embryology note)
• Non-surgical: Access method (Placeholder imaging note)
• Amyloid & tau: Shared pathology (Placeholder overlap note)
• OCT/Fundus: Imaging modality (Placeholder modality note)

Retina-brain developmental link

Placeholder: retina as an outgrowth of the diencephalon.

Rationale for ocular biomarkers

Placeholder: accessible proxy for otherwise invasive brain assessment.

Amyloid Beta in Retinal Layers

Placeholder: amyloid plaques found in retinal nerve fiber and ganglion layers.

• RNFL/GCL: Deposit location (Placeholder layer note)
• Curcumin fluor.: Detection method (Placeholder fluorescence note)
• Moderate: Correlation w/ PET (Placeholder correlation note)
• Early clinical: Study stage (Placeholder maturity note)

Detecting amyloid signal in vivo

Placeholder: fluorescent ligand imaging of retinal amyloid.

Comparing to cerebral amyloid burden

Placeholder: retinal signal tracked against PET SUVR.

Retinal Vasculature as a Brain Health Proxy

Placeholder: vessel narrowing and density loss mirror cerebral small vessel disease.

• Caliber/density: Vessel metric (Placeholder metric note)
• OCT-A: Imaging tech (Placeholder OCT angiography note)
• Cerebral SVD: Association (Placeholder association note)
• Small-moderate: Effect size (Placeholder effect note)

Vascular signatures of neurodegeneration

Placeholder: microvascular rarefaction as shared pathology.

OCT angiography measurements

Placeholder: quantifying vessel density changes non-invasively.

Non-Invasive Optical Imaging Techniques

Placeholder: OCT and fundus photography as low-cost screening instruments.

• <5 min: Scan time (Placeholder scan duration note)
• Much lower: Cost vs PET (Placeholder cost note)
• Micron-scale: Resolution (Placeholder resolution note)
• Optometry clinics: Deployment (Placeholder deployment note)

OCT structural imaging pipeline

Placeholder: cross-sectional retinal layer imaging workflow.

Fundus photography workflow

Placeholder: wide-field imaging for vascular assessment.

Screening Potential and Its Limits

Placeholder: retinal imaging as a triage tool, not a diagnostic replacement.

• Moderate: Sensitivity (Placeholder sensitivity note)
• Moderate: Specificity (Placeholder specificity note)
• Pre-screening: Role (Placeholder role note)
• PET/CSF: Gold standard (Placeholder confirmatory note)

Positioning as a triage tool

Placeholder: identifying candidates for further testing.

Need for confirmatory diagnostics

Placeholder: PET and CSF remain the diagnostic standard.

Placeholder: retinal imaging complements, does not replace, confirmatory testing.