Diagnostic efficiency of pan-immune-inflammation value to predict diabetic macular edema and its relationship with OCT-based biomarkers of inflammation.

Purpose: The objective of this study was to ascertain the predictive value of pan-immune-inflammation value (PIV) in the diagnosis of diabetic macular oedema (DME) and to analyse the relationship between PIV and inflammatory markers on optical coherence tomography (OCT).

Methods: A total of 155 patients were included in this observational study: 40 had diabetes without retinopathy, 60 had DME, and 55 were selected as healthy controls. All participants had a complete blood count. The neutrophil-to-lymphocyte ratio (NLR), systemic immune-inflammation index (SII), and PIV were calculated and compared. Multivariable regression models were used to further investigate the relationship between systemic inflammatory markers and other biomarkers and OCT markers.

Results: The DME group had significantly higher WBC (p < 0.001), monocyte (p = 0.003) and neutrophil counts (p = 0.024). PIV showed the highest sensitivity and area under the curve for predicting patients with DME in ROC curve analysis. The optimal PIV cut-off value was > 427.69 to distinguish patients with DME from healthy controls, and > 451.29 from diabetic patients without DR. In the regression analysis, HRF count was associated with PIV (p = 0.036), CMT (p = 0.005), and BCVA (p < 0.001). Additionally, the presence of SRF was associated with WBC (p = 0.043), PIV (p = 0.013), CMT (p = 0.007), and BCVA (p = 0.045).

Conclusion: PIV may be a useful marker of systemic neutrophil- and monocyte-mediated inflammation in DME, independent of diabetes duration and HbA1c, though further studies are needed to confirm its clinical utility and define an optimal cut-off value.