This study aimed to investigate the role of systemic inflammation in patients diagnosed with idiopathic intracranial hypertension (IIH) and to evaluate the relationship of various hematological inflammatory markers with retinal nerve fiber layer (RNFL) thickness.

The study included 30 newly diagnosed IIH patients and 30 age- and sex-matched healthy individuals. Neutrophil, lymphocyte, monocyte, platelet, immature granulocyte, and RDWSD levels were recorded in all cases; derived inflammatory markers, including the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), monocyte-to-lymphocyte ratio (MLR), systemic immune inflammation index (SII), and systemic inflammation response index (SIRI), were calculated from these parameters. RNFL thickness was measured by optical coherence tomography, and the relationships between lumbar puncture (LP) opening pressures and inflammatory parameters were analyzed.

In the IIH group, neutrophil, platelet, and immature granulocyte levels, as well as SII and SIRI values, were significantly higher compared to healthy controls (p < 0.05). RNFL thickness correlated positively with platelet, neutrophil, immature granulocyte counts, and SII (p < 0.05), whereas LP opening pressure and Frisen grade showed no association with inflammatory parameters (p > 0.05).Among the evaluated markers, immature granulocyte count demonstrated the highest diagnostic accuracy for distinguishing IIH, with an AUC of 0.824 in ROC analysis.

This study shows that inflammatory markers, including immature granulocyte count, SII, and SIRI, are significantly elevated in patients with IIH. Among these parameters, immature granulocyte count demonstrated the strongest associations with disease-related structural findings, suggesting its potential role as an inflammatory indicator in IIH. These findings highlight associations between systemic inflammatory parameters and IIH, without causality.