Objective To investigate the correlations of serum stromal cell-derived factor-1 (SDF-1), chemokine receptor 7 (CXCR7) and vascular density in the optic disc area with clinical stages in patients with normal-tension glaucoma (NTG).

Methods A total of 157 patients with NTG were included in the NTG group and divided into stage Ⅰ group (n=29), stage Ⅱ group (n=88), and stage Ⅲ group (n=40) based on different clinical stages; additionally, 56 healthy individuals with physical examinations in the same period were selected as control group. Serum SDF-1 and CXCR7 levels were compared between the NTG group and the control group; changes in vascular density in the optic disc area among patients with different clinical stages were analyzed; the multivariate Logistic regression analysis was conducted to explore the risk factors for NTG.

Results Compared with the control group, the NTG group had significantly increased serum levels of SDF-1 and CXCR7 (P < 0.05). Compared with the control group, patients in the NTG group showed significantly decreased densities of large vessels, capillaries, and the entire area, as well as significantly increased density of avascular areas (P < 0.05). The densities of capillaries and the entire area were significantly lower in the stage Ⅱ group and stage Ⅲ group than the stage Ⅰ group, while the density of avascular areas was significantly higher (P < 0.05). The densities of large vessels (r=-0.503, P=0.006), capillaries (r=-0.546, P < 0.001), and the entire area (r=-0.553, P < 0.001) were negatively significantly correlated with clinical stages, while the density of avascular area was positively significantly correlated with clinical stages (r=0.521, P=0.002). The proportions of patients with hypertension, history of alcohol consumption, family history of glaucoma, and high serum levels of SDF-1 and CXCR7 in the NTG group were significantly higher than those in the control group (P < 0.05). Multivariate Logistic regression analysis revealed that hypertension, family history of glaucoma, history of alcohol consumption, and high serum levels of SDF-1 and CXCR7 were risk factors for NTG (P < 0.05).

Conclusions Patients with NTG have significantly increased serum levels of SDF-1 and CXCR7. The densities of large vessels, capillaries, and the entire area are negatively correlated with clinical stages, while the density of avascular areas is positively correlated with clinical stages. Serum levels of SDF-1 and CXCR7 can serve as effective reference indicators for the diagnosis and clinical staging of NTG.