Relationship between expression of cyclooxygenase 2 and neovascularization in human pterygia

In present study, we are to test the relationship between cyclooxygenase 2 (COX-2) and angiogenesis in pterygium tissues from a group of Chinese patients. Here forty-five primary pterygium tissues and twenty-three normal bulbar conjunctival tissues were obtained during ophthalmologic surgeries. The primary pterygium samples were treated for the immunohistochemical evaluation of COX-2, CD31 and vascular endothelial growth factor (VEGF) antibodies for different tissues. In order to evaluate the relationship between COX-2 and neovascularization, a statistical analysis was performed using the SPSS 13.0 statistical software package. As results, in our study, 36 (80%) of the primary pterygia samples were found to be positive for COX-2 staining, which was not found in the normal conjunctivas. The density of the microvessels (MVD) was significantly increased in the COX-2 positive patients when compared to the COX-2 negative ones (19.06 ± 1.84 vs.10.44 ± 2.98, P=1.36×10-5) in the pterygia cases. In the group that was positive for COX-2, there were 39 (86.7%) samples with VEGF expression. Furthermore, the staining of both COX-2 and VEGF was localized to the lower and middle layers of the epithelium and the endothelial cells of the microvessels. When analyzed the relation between them, the expression of COX-2 showed a significant correlation with the MVD (P = 4.02×10-4) and VEGF (p = 2.72×10-4). In conclusion, the present study showed that COX-2 may play an important role in stimulating the angiogenesis of pterygium in concert with VEGF.