Abstract
Introduction: Overexpression of vascular endothelial growth factor (VEGF), cyclooxygenase-2 (COX-2), and p53 are the postulated aetiopathogenesis in pterygium. VEGF is responsible for the induction of COX-2 expression, whereas p53 plays an important role in the regulation of VEGF. This study aimed to evaluate the immunohistochemistry of COX-2 and p53 expressions from excised pterygium tissue from patients who received intralesional ranibizumab (anti-VEGF) injection 2 weeks prior to pterygium surgery.Materials and Methods: An interventional comparative study involving patients presenting with primary pterygium was conducted between September 2015 and November 2017. The patients were randomized into either the intervention or control group. Patients in the intervention group were injected with intralesional ranibizumab (0.5 mg/0.05 ml) 2 weeks prior to surgery. Both groups underwent pterygium excision followed by conjunctival autograft. Immunohistochemistry staining was performed to evaluate COX-2 and p53 expressions in the excised pterygium tissue.Results: A total of 50 patients (25 in both the intervention and control groups) were recruited. There were 34 (68%) patients with grade III pterygium and 16 (32%) patients with grade IV pterygium. There was statistically significant difference in reduction of COX-2 expression in the epithelial layer [84.0% (95% CI: 63.9, 95.5)] (p = 0.007) and stromal layer [84.0% (95% CI: 63.9, 95.5)] (p < 0.001) between intervention and control groups. There was no significant difference in the reduction of p53 expression between the two groups.Conclusion: This study demonstrated the possible use of intralesional anti-VEGF treatment prior to pterygium excision as a potential future modality of adjunctive therapy for pterygium surgery.
Highlights
Overexpression of vascular endothelial growth factor (VEGF), cyclooxygenase-2 (COX-2), and p53 are the postulated aetiopathogenesis in pterygium
VEGF is responsible for the induction of COX-2 expression, whereas p53 plays an important role in the regulation of VEGF
This study aimed to evaluate the immunohistochemistry of COX-2 and p53 expressions from excised pterygium tissue from patients who received intralesional ranibizumab injection 2 weeks prior to pterygium surgery
Summary
Overexpression of vascular endothelial growth factor (VEGF), cyclooxygenase-2 (COX-2), and p53 are the postulated aetiopathogenesis in pterygium. Pterygium appears as a triangular, wing-like fibrovascular growth from the bulbar conjunctiva over the limbus onto the cornea. It is postulated that UV-B radiation causes activation of the nuclear factor-kappa B (NF-kB) signaling pathway and leads to overexpression of cyclooxygenase-2 (COX-2) and vascular endothelial growth factor (VEGF). Overexpression of COX-2 and VEGF plays an important role in the angiogenesis and proliferating of fibrovascular tissue in the formation of pterygium [9, 10]. Recent studies have reported that overexpression of VEGF is produced by corneal fibroblasts in response to local conjunctival inflammation caused by environmental UV radiation, dryness, or dust [11,12,13,14]. COX-2 overexpression is correlated with vessel density and VEGF expression [16]
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