Choroidal changes in Crimean-Congo hemorrhagic fever

Abstract

Purpose: The goal of this study was to evaluate the effect of Crimean-Congo hemorrhagic fever (CCHF) on choroidal tissue.

Methods: Thirty-two CCHF patients and 34 healthy individuals were included in this cross-sectional study. All subjects were assessed using spectral domain optical coherence tomography and ImageJ software. The choroidal thickness (CT) in the subfoveal, nasal and temporal regions 1 mm from the foveal center was measured. The total choroidal area (TCA), luminal area (LA), stromal area (SA) and choroidal vascularity index (CVI) were calculated.

Results: The nasal (P=0.002), subfoveal (P=0.006), and temporal CT (P=0.028) were significantly higher in the CCHF group. The TCA (P=0.021), SA (P=0.001) was significantly higher, and LA/SA (P<0.001) and CVI (P<0.001) were significantly lower in patients with CCHF. Significant negative correlations were found between temporal CT (r=-0.387, P=0.029), TCA (r=-0.461, P=0.008), LA (r=-0.480, P=0.005) SA (r=-0.419, P=0.017) and fibrinogen. Nasal CT, temporal CT, TCA and SA tended to increase with the severity of the disease, while LA/SA tended to decrease when CCHF patients were grouped into mild and moderate stages.

Conclusions: This study demonstrates significant changes in the choroidal structure and vascular characteristics in CCHF patients. These findings may be associated with endothelial damage, vascular leakage, capillary fragility, impaired immune response, and/or inflammation.

Keywords: Choroidal thickness; Choroidal vascularity index; Crimean-Congo hemorrhagic fever; Fièvre hémorragique de Crimée-Congo; Indice de vascularisation choroïdienne; Optical coherence tomography; Tomographie par cohérence optique; Épaisseur choroïdienne.