text: The role of oxidative mechanisms in the etiopathogenesis of pterygium: a preliminary study.
  To evaluate the role of light-induced oxidative mechanisms in the pathogenesis of primary pterygium. Pterygium specimens were obtained from 18 eyes of 18 patients undergoing pterygial removal (group A), and normal conjunctival specimens were obtained from 18 eyes of 18 patients undergoing cataract surgery (group B). In all specimens, malondialdehyde (MDA) levels, superoxide dismutase (SOD) and catalase (CAT) activities were studied and compared. In group A, the mean SOD activity was lower, and the mean MDA level was higher when compared to group B. However, these differences did not reach clinical significance (p > 0.05). On the other hand, the mean CAT activity was statistically significantly higher in group A when compared to controls (p = 0.017). This preliminary study indicates that oxidative mechanisms seem to play a role in the pathogenesis of pterygium. These mechanisms are apparently activated by ultraviolet irradiation. Further studies are required to establish the role of oxidative mechanisms in the pathogenesis of primary or recurrent pterygia.