Investigating the Association between Angiogenic Cytokines and Corneal Neovascularization in Sulfur Mustard Intoxicated Subjects 26 Years after Exposure

OBJECTIVES: This study aimed to evaluate the associations between the concentrations of three major angiogenic cytokines–vascular endothelial growth factor-A165 (VEGF-A165), basic fibroblast growth factor (bFGF), and platelet-derived growth factor-BB (PDGF-BB)–in the tear of sulfur mustard (SM)-exposed subjects and corneal neovascularization (CNV) 26 years after exposure. MATERIALS AND METHODS: The concentrations of VEGF-A, bFGF, and PDGF-BB were measured by enzyme-linked immunosorbent assay (ELISA) in reflex tears of (i) SM-injured patients with CNV (positive case group including 18 individuals) and (ii) SM-injured patients without CNV (negative case group including 22 individuals). Then results were compared to corresponding values obtained from tears of 40 healthy control subjects. RESULTS: The mean concentrations of all investigated growth factors, VEGF-A165, bFGF, and PDGF-BB, were significantly higher in positive cases than controls (P ≤ 0.001, P = 0.028, and P = 0.041, respectively). Whereas, VEGF-A165 was the only growth factor which displayed significantly elevated concentrations in negative case group compared to the healthy individuals (P = 0.030). Additionally, the mean level of VEGF-A165 was also higher in positive patient group than negative patients (P = 0.022). Subjects with increased concentrations of tear VEGF-A165 were more than 10 times more likely to suffer from CNV than normal individuals (odds ratio (OR) = 10.43, confidence interval (CI): 2.14–38.46, P = 0.001), while elevated levels of bFGF and PDGF-BB increased the risk of CNV by about twofold. CONCLUSION: Although all investigated cytokines had increased in tears of positive patients, VEGF-A was the only one which showed a significant correlation with the severity of CNV, and thus played a crucial role in corneal angiogenesis.