The pathogenesis of pterygium: current concepts and their therapeutic implications.

Pterygium is a disease of the ocular surface that is associated with chronic UV exposure and is characterized by proliferation, inflammatory infiltrates, fibrosis, angiogenesis and extracellular matrix breakdown. Although pterygium is not fully understood, significant progress has been made toward understanding the mechanisms involved in its pathogenesis. In this review, we provide an update on the signaling pathways activated by UV light that result in induction of mediators responsible for the growth of pterygium. We also review the recent genetic studies on hereditary factors and provide a brief overview of the role of epithelial mesenchymal transition, bone marrow progenitor cells, and neuronal signals that may also contribute to the pathogenesis of pterygium. Therapeutic options for pterygium are discussed based on the mechanisms that perpetuate its growth.