title: Overexpression of vascular endothelial growth factor receptor 2 in pterygia may have a predictive value for a higher postoperative recurrence rate.
abstract: BACKGROUND
  To investigate the expression levels of vascular endothelial growth factor (VEGF), vascular endothelial growth factor receptor 1 (VEGFR-1) and VEGFR-2 in pterygium and to clarify the prognostic significance of these expressions in pterygia.
  
  
  METHODS
  A total of 40 surgically excised pterygia and 9 normal conjunctivae were immunohistochemically studied applying the streptavidin-biotin method in paraffin-embedded tissue sections. Monoclonal antibodies were targeted against VEGF, VEGFR-1 and VEGFR-2 proteins. At the sixth postoperative month, the recurrence rate was graded on a scale of 1-4.
  
  
  RESULTS
  The mean percentage of VEGF-positive epithelial cells was comparable in pterygium and normal conjunctivae. However, the pterygium group presented higher expression levels of VEGF in pterygia endothelial cells (p=0.05). In terms of VEGFR-1 expression in epithelial cells, no statistically significant difference was found between two groups (p=0.658). However, normal conjunctivae exhibited higher expression levels of VEGFR-1 in endothelial cells (p=0.002). Epithelial cells in pterygium presented higher combined scores of VEGFR-2 (87.5% and 22.2%, respectively) (p=0.013). While higher expression levels of VEGFR-2 were documented in pterygia endothelial cells, no VEGFR-2 immunoreactivity was observed in the endothelial cells of normal conjunctivae (p<0.001). Expression levels of VEGFR-2 in epithelial cells and endothelial cells were positively correlated with the postoperative recurrence grading system (p<0.001 and τ=0.627, p=0.001 and τ=0.508, respectively).
  
  
  CONCLUSIONS
  The results suggest that VEGF may play a key role through VEGFR-2 in the pathogenesis of pterygium. Moreover, overexpression of VEGFR-2 in pterygia may have a predictive value for a higher postoperative recurrence rate.
authors: Department of Ophthalmology, Erciyes University School of Medicine, Kayseri, Turkey.
authors: Koray
authors: K
authors: Gumus
authors: Department of Ophthalmology, Erciyes University School of Medicine, Kayseri, Turkey.
authors: Sarper
authors: S
authors: Karakucuk
authors: Department of Ophthalmology, Erciyes University School of Medicine, Kayseri, Turkey.
authors: G Ertugrul
authors: GE
authors: Mirza
authors: Department of Pathology, Erciyes University School of Medicine, Kayseri, Turkey.
authors: Hulya
authors: H
authors: Akgun
authors: Department of Ophthalmology, Erciyes University School of Medicine, Kayseri, Turkey.
authors: Hatice
authors: H
authors: Arda
authors: Department of Ophthalmology, Erciyes University School of Medicine, Kayseri, Turkey.
authors: Ayse O
authors: AO
authors: Oner
mesh_terms: D015415:Biomarkers / Q000378:metabolism*; D004847:Epithelial Cells / Q000378:metabolism; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications; D011625:Pterygium / Q000175:diagnosis* / Q000378:metabolism* / Q000601:surgery; D012008:Recurrence; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism; D040281:Vascular Endothelial Growth Factor Receptor-1 / Q000378:metabolism; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000378:metabolism*
chemical_list: D015415:Biomarkers; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; C000588866:KDR protein, human; D040281:Vascular Endothelial Growth Factor Receptor-1; D040301:Vascular Endothelial Growth Factor Receptor-2
keywords: Conjunctiva