The pathogenesis of pterygia.

Pterygium is an active, invasive, inflammatory process, a key feature of which is focal limbal failure. In a two-stage process, "conjunctivalization" of the cornea occurs with tissue characterized by extensive chronic-inflammation, cellular proliferation, connective tissue remodeling, and angiogenesis. An understanding of this process has resulted in efforts aimed at limbal reconstruction, which is considered the gold standard for surgical care. Although good results have been obtained with other treatment methods, a long-term approach to follow-up with at least 5-year survival figures is desirable. Sophisticated analyses of the tear film and surface epithelium in patients with pterygium may help explain symptoms. The efficacy, at least in the short term, of nonsteroidal anti-inflammatory drugs in the treatment of inflamed pterygia has been confirmed. Corneal topographic analysis has shown that surgery reduces induced astigmatism and also causes subtle changes that may explain postsurgical improvements in vision.