Inflammatory Stability Index Correlates with Retinal Nerve Fiber Layer Reduction in Glaucoma

Area of Science:

• Ophthalmology
• Neuroscience
• Immunology

Background:

• Neuroinflammation is a known factor in glaucomatous neurodegeneration.
• The prognostic significance of inflammatory markers in glaucoma remains uncertain.
• Previous research focused on absolute cytokine levels, potentially missing crucial temporal dynamics.

Purpose of the Study:

• To investigate the association between inflammatory stability over time and retinal nerve fiber layer (RNFL) reduction in primary open-angle glaucoma (POAG).
• To introduce and validate the Inflammatory Stability Index (ISI) as a measure of temporal inflammatory patterns.

Main Methods:

• A prospective longitudinal cohort study involving 57 participants (19 controls, 38 POAG patients) over 24 months.
• Serum cytokine profiling (IL-1β, TNF-α, IL-6) and RNFL measurements were collected.
• The Inflammatory Stability Index (ISI) was developed using the formula: ISI = Median[cytokines] / (1 + IQR[cytokines]) to quantify inflammatory stability.

Main Results:

• The ISI significantly correlated with RNFL progression rate (r = -0.491, p = 0.002).
• Patients with stable-high inflammation (ISI > 3.5) exhibited 74% faster RNFL progression compared to those with volatile-low inflammation (ISI < 1.6).
• The ISI demonstrated acceptable accuracy in identifying rapid progressors (AUC = 0.76) and remained significant after multivariable adjustments.

Conclusions:

• Inflammatory stability patterns, as quantified by the ISI, are more informative for predicting glaucoma progression than absolute cytokine levels.
• The ISI can identify high-risk inflammatory phenotypes in POAG patients.
• This index may aid in personalized management strategies and patient stratification for closer monitoring.