Culture and characterisation of epithelial cells from human pterygia

Background/aims-Pterygia are a common disorder of the ocular surface. The d isease represents a chronic fibrovascular and degenerative process thought to originate at the conjunctival-corneal junction, where altered limbal ste m cells are proposed to be the cell of origin. Extensive epidemiological ev idence exists to implicate ultraviolet B irradiation in the pathogenesis of pterygia. To date no animal or in vitro culture model has been developed t o test such an hypothesis. The aim of this study was to establish and chara cterise a pure population of epithelial cells derived from pterygium tissue . Methods-Tissue specimens were obtained fi om patients undergoing pterygium excision. Explants were cultured in either serum free or serum supplemented medium. Primary and passaged cells were processed for light microscopy, an alysed by how cytometry, and characterised immunohistochemically using spec ific antibodies. Results-In serum free culture, cuboidal cells with typical morphology of ep ithelial cells migrated from the pterygium explants from 3 days onwards and eventually formed a cohesive monolayer. Passaged cells consisted of 98.4% cytokeratin positive cells and demonstrated immunoreactivity for multiple c ytokeratins, including AE1, AE3, AE5, but were negative for AE8. These cell s also expressed an epithelial specific antigen, together with vimentin and mucin, as did epithelial cells in sections of pterygia. Conclusions-A relatively simple method of isolating pterygium epithelial ce lls has been established. Cultured pterygium epithelial cells are phenotypi cally and functionally similar to their in vivo counterparts with respect t o keratin, vimentin, and mucin expression. In vitro assays using these cell s may aid in elucidating the pathogenesis of pterygia.