Neurofilament light chain levels differentiate ischemic from inflammatory optic neuropathies

Area of Science:

• Ophthalmology
• Neurology
• Biomarker Research

Background:

• Serum neurofilament light chain (sNfL) is a potential biomarker for neuroaxonal damage.
• Differentiating non-arteritic anterior ischemic optic neuropathy (NAION) from optic neuritis (ON) is clinically important.
• ON can be associated with autoimmune conditions like aquaporin-4 (AQP4)-IgG positive neuromyelitis optica spectrum disorder (NMOSD) and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD).

Purpose of the Study:

• To assess the discriminatory capacity of sNfL in distinguishing NAION from AQP4-IgG+NMOSD and MOGAD-associated ON.
• To evaluate the correlation between sNfL levels during an acute attack and subsequent visual outcomes.

Main Methods:

• sNfL levels were measured in patients with acute optic neuropathies (NAION, AQP4-IgG+NMOSD ON, MOGAD ON) and healthy controls.
• Statistical analysis was performed to compare sNfL levels across groups and assess correlations with visual acuity.

Main Results:

• Significant differences in sNfL levels were observed between all patient cohorts and controls (p < 0.001).
• sNfL levels were significantly higher in NAION compared to ON (p < 0.001).
• A threshold of 60 pg/mL for sNfL showed high specificity (100%) in discriminating NAION from ON (AUC = 0.82).
• sNfL levels correlated with final visual acuity, independent of the optic neuropathy etiology (R² = 0.49, p < 0.001).

Conclusions:

• sNfL levels show potential as a biomarker to differentiate NAION from AQP4-IgG+NMOSD and MOGAD-associated ON.
• sNfL levels may serve as a predictor of long-term visual prognosis in patients with optic neuropathies.
• Further research using standardized z-scores is recommended for robust clinical interpretation.