Retinal Hyperreflecting Foci Associate With Cortical Pathology in Multiple Sclerosis.

Area of Science:

• Neuroimmunology
• Ophthalmology
• Radiology

Background:

• Microglia, the brain's immune cells, are activated in multiple sclerosis (MS).
• Retinal microglia activation, visualized as hyperreflecting foci (HRF), is widespread in MS.
• The association between HRF and clinical/radiological parameters in early relapsing-remitting MS (RRMS) requires evaluation.

Purpose of the Study:

• To assess the presence and number of retinal HRF in patients with early RRMS.
• To investigate the correlation between HRF and clinical/radiological disease parameters.
• To explore HRF as a potential prognostic biomarker in RRMS.

Main Methods:

• 80 RRMS patients underwent optical coherence tomography (OCT) and 3T-MRI near disease onset.
• Patients were followed for 43 months, assessing no evidence of disease activity (NEDA) status.
• Exclusion criteria included a history of optic neuritis (ON) or suggestive MRI/OCT findings.

Main Results:

• HRF counts were significantly higher in the inner nuclear layer (INL) of RRMS patients compared to controls.
• HRF count correlated with INL volume and gray matter (GM) lesion volume.
• Higher INL HRF counts were associated with both clinical (cNEDA) and radiological (rNEDA) disease activity.

Conclusions:

• A strong association exists between retinal microglial proliferation (HRF) and cortical pathology in RRMS.
• Microglial activation at baseline, indicated by HRF, may predict future inflammatory events.
• HRF shows promise as a prognostic biomarker for MS, warranting further investigation.