Biomarkers

Area of Science:

• Ophthalmology and Neurology
• Biomarker Discovery
• Medical Diagnostics

Background:

• Non-invasive retinal imaging using polarized light can identify protein deposits that predict brain pathology.
• Previous studies differentiated retinal deposits in Alzheimer's disease (AD) from alpha-synuclein-related neurodegenerative diseases (NDDs).
• This study investigates polarized light interactions in deposits involving TDP-43, comparing them to amyloid deposits in AD.

Purpose of the Study:

• To compare polarized light interactions of retinal deposits associated with TDP-43 proteinopathies (ALS/FTLD) with those of amyloid deposits in Alzheimer's disease (AD).
• To evaluate the potential of this technique as an inexpensive, dye-free, differential diagnostic tool for neurodegenerative diseases.
• To enable earlier and more appropriate treatments by facilitating differential diagnosis.

Main Methods:

• Retinal imaging using polarized light was performed on samples from individuals with ALS, FTLD, and AD.
• Deposits presumed to be amyloid beta (in AD) and TDP-43 (in ALS/FTLD) were imaged.
• Nine different polarized light interactions were calculated for each deposit and compared between disease groups.

Main Results:

• Retinal deposits consistent with AD (amyloid beta) and ALS/FTLD (TDP-43) were visualized using polarized light.
• Significant differences in multiple polarized light interactions were observed between AD and TDP-43 retinal deposits.
• Some overlap in interaction strengths and deposit areas suggests potential for combined diagnostic markers.

Conclusions:

• Distinct polarized light interactions correlate with different protein deposits (amyloid vs. TDP-43) in the retina, mirroring brain pathology.
• Combining these interactions may lead to early, non-invasive, and cost-effective differential diagnoses for neurodegenerative diseases.
• This approach holds promise for diagnosing conditions involving amyloid beta, alpha-synuclein, and TDP-43.