title: Cyclooxygenase-2 expression in primary and recurrent pterygium.
abstract: 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.
  
  
  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.
authors.affiliation: Department of Pathology, Suleyman Demirel University School of Medicine, Isparta, Turkey. nerminkarahan@hotmail.com
authors.forename: Nermin
authors.initials: N
authors.lastname: Karahan
authors.forename: Sirin
authors.initials: S
authors.lastname: Baspinar
authors.forename: Metin
authors.initials: M
authors.lastname: Ciris
authors.forename: Cetin Lutfi
authors.initials: CL
authors.lastname: Baydar
authors.forename: Nilgun
authors.initials: N
authors.lastname: Kapucuoglu
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D051546:Cyclooxygenase 2 / Q000378:metabolism*; D004848:Epithelium / Q000201:enzymology; D005260:Female; D005347:Fibroblasts / Q000201:enzymology; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D008875:Middle Aged; D011625:Pterygium / Q000201:enzymology* / Q000601:surgery; D012008:Recurrence
chemical_list: D051546:Cyclooxygenase 2