Abstract
Purpose: :
Pterygium is a growth of fibrovascular tissue onto the cornea and angiogenesis is important in the pathogenesis of it. The ephrin-Eph system, especially ephrinB2 and its receptor EphB4, was shown to play an important role in tumor angiogenesis. It was also reported that they were involved in the pathogenesis of ocular angiogenesis. This study was designed to investigate the expression of ephrinB2 and its receptor EphB4 in pterygia and its relations with microvessel density (MVD).
Methods: :
Samples of pterygia (n=28) and normal bulbar conjunctival tissue (n=11) were submitted to immunohistochemical study. Microvessel density was assessed by using antibody against CD31. EphrinB2 and EphB4 protein expression levels and the tissue distribution were also evaluated in these samples.
Results: :
Immunohistochemistry showed that pterygia presented with statistically significant higher average count of microvessels compared to normal conjunctivae (21.00+/-4.06 vs 6.07+/-1.75 per high power field, P<0.01). EphrinB2 and EphB4 staining was present at a dense level in the total epithelium of the head portions of both primary and recurrent pterygial specimens, although just in the basal and parabasal layer of the epithelium of most of the normal conjunctivae. And statistically significant positive correlation between MVD values and stromal EphB4 expression was found (P<0.01).
Conclusions: :
EphrinB2 and EphB4 appear to be over-expressed in pterygia, and they may play important roles in angiogenesis in the pathogenesis of pterygium.