Role of soluble vascular endothelial growth factor receptor-2 in macular oedema with central retinal vein occlusion

Background and aims To measure soluble vascular endothelial growth factor receptor-2 (sVEGFR-2) in the vitreous fluid of patients with central retinal vein occlusion (CRVO) and macular oedema or patients with idiopathic macular hole, and to investigate the relation between sVEGFR-2 and vascular endothelial growth factor (VEGF). Methods Vitreous fluid samples were obtained from 44 patients during vitreoretinal surgery (29 patients with CRVO and 15 with macular hole). Then the sVEGFR-2 and VEGF levels were measured by ELISA. Retinal ischaemia was evaluated by measuring the area of capillary nonperfusion on fluorescein angiograms with the public domain Scion Image program. Macular oedema was examined by optical coherence tomography. Results CRVO patients had significantly higher vitreous levels of sVEGFR-2 (median (IQR): 1200 pg/ml (835-1740)) than macular hole patients (945 pg/ml (691-1292), p=0.042)). They also had significantly higher vitreous VEGF levels (324 pg/ml (114-1218) vs 15.6 pg/ml (15.6-15.6), p<0.001). In CRVO patients, the vitreous level of VEGF was significantly correlated with the severity of macular oedema (rho=0.50, p=0.008), but the sVEGFR-2 level was not. The product (sVEGFR-2XVEGF) was also significantly correlated with the severity of macular oedema (rho=0.49, p=0.008). The strength of the association with macular oedema was similar for the product (sVEGFR-2XVEGF) and for VEGF alone. Conclusion These findings suggest that macular oedema in CRVO patients is more closely related to VEGF than sVEGFR-2.