Hyperreflective Foci in the Inner Nuclear Layer: Proof-of-Concept for an Optical Coherence Tomography Derived...

Area of Science:

• Neuroimmunology
• Ophthalmology
• Neuroimaging

Background:

• Microglia play a key role in multiple sclerosis (MS) pathogenesis.
• Current monitoring tools for microglial pathology in MS are limited.
• Hyperreflective foci (HRF) are detectable in the retina using optical coherence tomography (OCT).

Purpose of the Study:

• To investigate if retinal hyperreflective foci (HRF) detected by optical coherence tomography (OCT) can serve as a marker for microglial pathology in multiple sclerosis (MS).

Main Methods:

• Utilized optical coherence tomography (OCT) to detect hyperreflective foci (HRF) in the inner nuclear layer (INL) of the retina.
• Quantified HRF counts in individuals with relapsing and progressive MS.
• Correlated HRF counts with global white and gray matter volumes and [18F]GE-180 uptake in deep gray matter using positron emission tomography (PET).

Main Results:

• HRF counts were significantly increased in patients with relapsing and progressive MS compared to controls.
• A positive correlation was observed between HRF counts and [18F]GE-180 uptake, a marker of microglial activation, in deep gray matter.
• HRF counts also correlated with global white and gray matter integrity.

Conclusions:

• Retinal hyperreflective foci (HRF) detected by OCT show promise as a non-invasive imaging biomarker for microglial pathology in multiple sclerosis (MS).
• HRF may reflect disease activity and microglial involvement in both white and gray matter lesions.
• Further research is warranted to validate HRF as a reliable tool for monitoring MS progression and treatment response.