Overexpression of vascular endothelial growth factor receptor 2 in pterygia may have a predictive value for a higher postoperative recurrence rate

• Published in: British journal of ophthalmology Vol. 98; no. 6; p. 796
• Main Authors: Gumus, Koray, Karakucuk, Sarper, Mirza, G Ertugrul, Akgun, Hulya, Arda, Hatice, Oner, Ayse O
• Format: Journal Article
• Language: English
• Published: England 01-06-2014
• Subjects: Biomarkers - metabolism; Epithelial Cells - metabolism; Female; Humans; Immunoenzyme Techniques; Male; Middle Aged; Postoperative Complications; Pterygium - diagnosis; Pterygium - metabolism; Pterygium - surgery; Recurrence; Vascular Endothelial Growth Factor A - metabolism; Vascular Endothelial Growth Factor Receptor-1 - metabolism; Vascular Endothelial Growth Factor Receptor-2 - metabolism; Conjunctiva
• ISSN: 1468-2079
• DOI: 10.1136/bjophthalmol-2012-301944

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.
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.
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).
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.