Relationship between retinal blood flow and cytokines in central retinal vein occlusion

BACKGROUND: We evaluated the relationship between retinal blood flow and aqueous humor levels of cytokines/growth factors in patients with central retinal vein occlusion (CRVO). METHODS: In an observational study, 64 eyes of 64 CRVO patients were examined before anti-vascular endothelial growth factor (VEGF) therapy. Blood flow was assessed in large vessels around and at the optic disk by determining the mean blur rate using laser speckle flowgraphy. Aqueous humor samples were obtained from the patients during anti-VEGF therapy and levels of the following molecules were measured by the suspension array method: soluble VEGF receptor (sVEGFR)-1, sVEGFR-2, VEGF, plancental growth factor (PlGF), platelet-derived growth factor (PDGF)-AA, soluble intercellular adhesion molecule (sICAM)-1, monocyte chemotactic protein (MCP)-1, interleukin (IL)-6, IL-8, IL-12(p70), and IL-13. RESULTS: The mean blur rate of the affected eye was significantly lower than that of the unaffected eye. The mean blur rate showed a significant negative correlation with the log-transformed aqueous humor levels of PlGF, sICAM-1, and IL-8, but not VEGF. CONCLUSIONS: These findings suggest that retinal blood flow velocity might be more strongly correlated with inflammatory factors than VEGF in patients with nonischemic CRVO and macular edema.