Systemic Inflammatory Markers and HDL Levels in Keratoconus Patients

Overview

This retrospective case-control study evaluated systemic inflammatory markers related to high-density lipoprotein (HDL) in patients with progressive keratoconus (KC). Among markers studied, the platelet to HDL ratio (PHR) was significantly elevated in KC patients compared to controls, suggesting a potential role in systemic inflammation associated with KC.

Background

Keratoconus is a progressive, bilateral corneal ectatic disorder characterized by thinning and conical protrusion of the central cornea. Although traditionally considered noninflammatory, recent evidence indicates increased local and systemic inflammatory markers in KC. Ratios involving neutrophils, lymphocytes, monocytes, platelets, and HDL cholesterol have emerged as novel systemic inflammatory biomarkers. This study aimed to assess these markers, including MHR, NHR, LHR, NLR, and PHR, and their correlation with corneal topographic parameters in KC patients.

Data Highlights

Key Findings

• PHR was significantly elevated in patients with progressive keratoconus compared to healthy controls (p=0.004, adjusted p=0.0215).
• No significant differences were found in MHR, NHR, LHR, or NLR between KC patients and controls.
• There were no statistically significant correlations between systemic inflammatory markers and corneal topographic parameters or best corrected visual acuity (BCVA).
• The optimal PHR cutoff value for KC diagnosis was 4807, with 74.8% sensitivity and 45.5% specificity (AUC=0.616).
• The study included 103 KC patients and 99 matched controls with no significant differences in age or gender distribution.

Clinical Implications

The elevated PHR in keratoconus patients suggests that platelet to HDL ratio may serve as a systemic inflammatory biomarker associated with KC progression. However, the modest specificity and lack of correlation with corneal parameters indicate that PHR should be interpreted cautiously and not used in isolation for clinical decision-making. Further research is needed to clarify the role of systemic inflammation in KC pathogenesis and its potential as a therapeutic target.

Conclusion

This study identifies PHR as a significant systemic inflammatory marker elevated in progressive keratoconus patients, although its clinical utility remains limited by modest diagnostic accuracy and lack of correlation with disease severity. These findings support the involvement of systemic inflammation in KC and warrant further investigation.

References

1. Sakarya University Faculty of Medicine IRB 2024 -- Assessment of Systemic Inflammatory Markers Linked to HDL Levels in Keratoconus