Persistent Proinflammatory Cytokine Profile in the Tear Fluid of Stable Keratoconus: Rethinking Clinical Quiescence

Area of Science:

• Ophthalmology
• Immunology
• Biomarker Discovery

Background:

• Keratoconus is traditionally viewed as noninflammatory corneal ectasia.
• Emerging evidence suggests an underlying inflammatory component in keratoconus.
• This study investigates inflammatory activity in stable keratoconus patients.

Purpose of the Study:

• To evaluate persistent inflammatory activity in tear fluid of stable keratoconus patients.
• To compare tear cytokine profiles between keratoconus patients and healthy controls.
• To assess the potential of tear cytokines as biomarkers for keratoconus.

Main Methods:

• A cross-sectional case-control study design was employed.
• Tear fluid samples were collected from 23 stable keratoconus patients and 25 controls.
• Concentrations of nine key cytokines were quantified using a multiplex assay, with statistical analyses including correlation and ROC curves.

Main Results:

• Stable keratoconus patients exhibited significantly elevated tear fluid inflammatory cytokines compared to controls (P < 0.05).
• A coordinated cytokine network was observed in keratoconus patients, indicating persistent immune activation.
• Interleukin-6 (IL-6) showed moderate discriminatory performance (AUC = 0.68).

Conclusions:

• Clinically stable keratoconus is associated with a distinct proinflammatory tear cytokine profile.
• This challenges the traditional noninflammatory view of keratoconus.
• Tear fluid inflammatory biomarkers may be useful for monitoring disease activity and guiding therapy.