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.