Офтальмохирургия (Apr 2013)
The role of growth factors in the formation and progression of pterygium
Abstract
ABSTRACT Purpose. To determine a role of epidermal growth factors and vasal proliferative proteins in the pathogenesis of progressive pterygium based on data of immunohistochemical and morphological studies of tissues. Material and methods. The study included a main group of patients with primary pterygium of the progressive stage III-IV (30 eyes, 28 patients), the mean age was 57±7 years. The surgical procedure the pterygium removal was performed according to the Cermak method in all cases for therapeutic purposes and for a further morphological and immunohistochemical study of pterygium tissue. The clinical assessment of postoperative condition was carried out in the early postoperative period and in 6 and 12 months after surgery. The immunohistochemical study was made with the use of monoclonal antibodies and the visualization system (the DAKO company, Denmark): CD 31 (clone JC70A), CD 34 ClassII (clone QBEnd 10), Vascular Endothelial Growth Factor VEGF (clone VG1), Epidermal growth factor EGF (clone DAK-H1-WT). The intensity of coloration of objects was estimated by colorimetric index on a 4-point scale and reflected the quantity of the studied factors. For histological examination the removed pterygium with the tissues of the cornea and conjunctiva was stained with hematoxylin-eosin with a subsequent analysis and a m icro-photographing. Results and discussion. The pterygium concerning the structure and function is characterized by an impaired homeostasis of the tissues of the conjunctiva and cornea, expressed in a change of epithelial-stromal relations, disorganization of the fibrous structures of connective tissue, violations in the microcirculatory bed. As a result of the immunohystochemical research, the expression of growth factors was identified in all cases of main group. The expression of epidermal factor was diagnosed in 27 objects with the index (++) and 3 objects with the index of (+). The CD31 expression was revealed: ++++ in 28 objects, in 1 object +++, and in 1 object ++. CD34 expression was revealed: ++++ in 26 objects, in 4 objects ++. The VEGF expression was revealed: ++++ in all 30 objects. In the control group the above-described changes were not revealed, that is the expression of epidermal and vascular growth factors were determined. Conclusion. Thus, the analysis of the peculiarities of growth of the conjunctive epithelium, angioarchitectonique in the tissues of the pterygium and underlying cornea allows assuming that the starting factor of the pathological process is the primary growth of conjunctive epithelium with the accompanying growth of vasculature. The expressive level of epidermal and vasoproliferative growth factors in pterygium can serve as a prognostic sign of pterigium recurrence. The identification of VEGF expression can be a condition on the use of anti-VEGF therapy in the prevention of recurrence.
