Purpose: The pterygium is a growth onto the cornea of fibrovascular tissue that is continuous with the conjunctiva, while the mechanisms of cell proliferation in pterygium epithelium are unknown. The aim of this study is to analyze the histopathology and the expression of cell cycle-related molecules in pterygium tissues.
Methods: Seven pterygia were surgically removed using the bare-sclera procedure, and three normal bulbar conjunctivas were also obtained. Formalin-fixed, paraffin-embedded tissues were analyzed by immunohistochemistry with anti-p27 (KIP1), cyclin D1, and Ki67 antibodies.
Results: Conjunctival epithelium consisted of several layers of round cells with a few goblet cells. Nuclear immunoreactivity for p27(KIP1) was noted in many normal epithelial cells, where cyclin D1 and Ki67- positive nuclei were intermingled. A variety of goblet cells were located in the superficial layer of the pterygium head as well as those of the body epithelia. Several pterygium epithelial cells were p27(KIP1)- positive, whereas nuclear immunoreactivity for cyclin D1 and Ki-67 was detected in many epithelial cells. In contrast, immunoreactivity for p27(KIP1), cyclin D1, and Ki67 was hardly detected in the pterygium stroma.
Conclusion: It is suggested that pterygium growth and development are associated with the proliferation of epithelium, which is possibly involved with the expression of cell cycle-related molecules.
- cyclin D1