Abstract
Abstract: :
Purpose: Pterygia have been considered to originate from pingueculae. However, most pterygia develop in the nasal bulbar conjunctiva close to the limbus, while pingueculae can occur on both the nasal and temporal sides. To explore the pathogenesis of pterygium, histopathological differences between primary and recurrent pterygium were examined. Methods: Samples of primary (n=37) and recurrent (n=8) pterygial tissues were taken from pterygium surgery with free conjunctival transplantation. Tissues were placed on filter paper to avoid shrinkage before fixation. Tissues were subsequently cut into halves along the long axis of the pterygium, then embedded in paraffin. Sections were stained using hematoxylin and eosin, and Elastica van Gieson (EVG). Elastotic degeneration and basophilic degeneration, which are known as characteristic findings in pingueculae, were examined under light microscopy. Results: In 35 of 37 primary pterygia (94.6%), both elastotic degeneration and basophilic degeneration were present, indicating that most primary pterygia display the same histopathological characteristics as pinguecula. However, all 8 recurrent pterygia displayed abnormal elastic fibers and hyalinized connective tissues, with no basophilic degeneration. Conclusions: The present results suggest that abnormal elastogenesis and dysfunction of barriers in the limbus might be involved in the pathogenesis of pterygium, in addition to the presence of pinguecula.
Keywords: pathology: human • conjunctiva • pathobiology