[Changes of cytokines in the aqueous humor of neovascular glaucoma at the angle-closure stage].

Objective: To evaluate the concentration of cytokines in the aqueous humor of neovascular glaucoma (NVG) patients at the angle-closure stage in different treatment periods and its relationship with recurrence. Methods: A prospective case-control study. Angle-closure stage NVG patients who came to Peking University Third Hospital from September 2018 to September 2019 were enrolled and followed-up for at least 12 months. Patients received triple sequential therapy, including anti-vascular endothelium growth factor (VEGF) injection, trabeculectomy, and panretinal photocoagulation. The aqueous humor before anti-VEGF treatment, before trabeculectomy, and during recurrence was collected. Multiplex bead immunoassay was applied to measure the concentration of 45 cytokines including VEGF, interleukin (IL), and chemokine. The relevant data were compared with the values of 25 proliferative diabetic retinopathy (PDR) patients and 24 age-related cataract patients undergoing phacoemulsification as controls. The concentration of cytokines was presented as M (Q1, Q3). The nonparametric Kruskal-Wallis H test was applied to compare the cytokine concentration between the NVG group and controls. The difference between the recurrence and non-recurrence groups was compared with the Mann-Whitney U test. Results: The average age of NVG patients was (60±11) years, and there were 22 males and 10 females. No significant differences were found in age and gender between the NVG group and the two control groups (both P>0.05). The median concentrations of VEGF in the NVG group before anti-VEGF treatment, before trabeculectomy, and after recurrence were 2 151.3 (1 433.1, 4 280.0) ng/L, 655.4 (287.3, 836.3) ng/L and 2 003.4 (1 603.1, 2 468.9) ng/L respectively. The concentrations of VEGF before anti-VEGF treatment and after recurrence in the NVG group were significantly higher than the PDR group [453.8 (189.9, 595.8) ng/L] and the cataract group [143.5 (112.7, 269.8) ng/L] (all P<0.05). The median concentration of programmed cell death protein ligand 1 (PD-L1) was 38.9 (22.4, 50.6) ng/L before anti-VEGF treatment, higher than that in the PDR group [12.0 (6.3, 20.1) ng/L] and the cataract group [14.6 (11.4, 19.3) ng/L]. The median concentration of fractalkine was 242.7 (189.0, 306.7) ng/L, higher than that in the PDR group [131.1 (119.1, 157.6) ng/L] and the cataract group [116.7 (10.2, 135.9) ng/L]. The median concentration of IL-7 was 18.0 (12.0, 32.7) ng/L, higher than that in the PDR group [7.7 (2.0, 10.8) ng/L] and the cataract group [3.3 (1.9, 6.8) ng/L]. The median concentration of eotaxin was 84.0 (52.4, 122.7) ng/L, higher than that in the PDR group [26.6 (17.1, 72.3) ng/L] and the cataract group [7.1 (5.6, 14.8) ng/L]. The median concentration of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) was 3.6 (2.8, 6.4) ng/L, higher than that in the cataract group [1.1 (0.3, 2.3) ng/L]. All the differences were statistically significant (all P<0.05). There were no significant differences between the NVG and control groups in other cytokines or other treatment periods (all P>0.05). Six NVG patients suffered recurrence during the follow-up. The baseline concentration of IL-7 of these patients [10.5 (8.4, 16.0) ng/L] was significantly lower than that in patients who did not have recurred disease [22.7 (15.7, 34.1) ng/L] (Z=-2.74, P<0.01). Conclusions: In the angle-closure stage of NVG patients, the concentrations of VEGF, PD-L1, fractalkine, IL-7, eotaxin, and TRAIL in the aqueous humor significantly increase during the onset of disease. Lower IL-7 may indicate a recurring tendency.