Cyclooxygenase-2 expression in primary and recurrent pterygium.

BACKGROUND: Pterygia are common, benign, fibrovascular, and infiltrative processes of the corneo-conjunctival junction of unknown pathogenesis. Cyclooxygenase-2 (COX-2) mediates the rate-limiting step in arachidonic acid metabolism. Extensive evidence indicates that the COX-2 prostanoid pathway is involved in inflammation. The aim of the study was to document the immunohistochemical expression of COX-2 in primary and recurrent pterygia. MATERIALS AND METHODS: In this study, 21 primary pterygia and 12 recurrent pterygia from subjects undergoing pterygium surgery and six normal corneal-scleral tissue specimens were studied immunohistochemically for COX-2 expression. RESULTS: COX-2 was expressed in primary pterygia and recurrent pterygia specimens. There was a statistically significant difference in COX-2 expressions in fibroblasts between primary and recurrent pterygium cases ( P = 0.001). There were statistically significant differences in COX-2 expressions in surface epithelium ( P = 0.028) and stromal inflammatory cells ( P =0.000) between control tissues and primary pterygia tissues. We also detected statistically significant differences in COX-2 expressions in surface epithelium ( P =0.000), stromal fibroblasts P =0.000 (stromal fibroblasts and inflammatory cells), vessels ( P = 0.027) and inflammatory cells ( P =0.001) between control tissues and recurrent pterygia tissues. CONCLUSIONS: This is the first study to document the expression of COX-2 in primary and recurrent pterygia. In our opinion after excision of pterygia, fibroblastic proliferation continues and this contributes to recurrence.

Matrix metalloproteinase-9 expression in pterygium

OBJETIVO: Avaliar a expressão da metaloprotease de matriz (MMP)-9 nos pterígios. MÉTODOS: Foi realizado na Faculdade de Medicina de Botucatu estudo prospectivo, aleatório, com o intuito de avaliar a expressão da metaloprotease de matriz na cápsula de Tenon normal e de pterígios primários e recidivados, usando o método da imuno-histoquímica e o sistema computadorizado de análise de imagem. Os resultados foram avaliados estatisticamente. RESULTADOS: A expressão da metaloprotease de matriz foi semelhante na cápsula de Tenon normal e nos pterígios primários e recidivados. CONCLUSÃO: A expressão da metaloprotease de matriz na cápsula de Tenon normal e nos pterígios primários ou recidivados é semelhante, o que nos leva a concluir que esta metaloprotease de matriz não esteja envolvida na gênese ou na recidiva do pterígio.