Cultured human ocular surface epithelium on therapeutic contact lenses

Background: This study was initiated after observation of some intriguing epithelial growth properties of contact lenses used as a bandage for patients after pterygium surgery. Aim: To determine the efficacy of culturing human ocular surface epithelial cells on therapeutic contact lenses in autologous serum with a view of using this system to transfer epithelial cells to patients with persistent corneal or limbal defects. Methods: Excess graft tissue resected from patients undergoing pterygium surgery ( n = 3) consisting of limbal epithelium was placed on siloxane - hydrogel contact lenses ( lotrafilcon A and balafilcon A). Limbal explants were cultured in media with 10% autologous serum. Morphology, proliferative capacity and cytokeratin profile were determined by phase contrast, light and electron microscopy, and immunohistochemical analysis. Results: Lotrafilcon A contact lenses sustained proliferation and migration from limbal tissue. Cells became confluent after 10 - 14 days and consisted of 2 - 3 layers with a corneal phenotype ( CK3(+)/ CK12(+)/ CK19(-)) and a propensity to proliferate ( p63(+)). Electron microscopy showed microvilli on the apical surface with adhesive projections, indicating that these cells were stable and likely to survive for a long term. Growth was not observed from limbal explants cultured on balafilcon A contact lenses. Conclusion: A method for culturing human ocular surface epithelium on contact lenses that may facilitate expansion and transfer of autologous limbal epithelial cells while avoiding the risks associated with transplanting allogeneic tissue has been developed. This technique may be potentially useful for the treatment of patients with limbal stem cell deficiency.