Epithelialization of a synthetic polymer in the feline cornea: A preliminary study

PURPOSE. This study examined the potential of a synthetic polymer to suppor t stable epithelial growth when implanted in the feline cornea. METHODS. A perfluoropolyether-based polymer was cast into lenticules that w ere coated with collagen I and implanted in four feline corneas. Epithelial growth onto the lenticules was monitored clinically for 6 weeks, after whi ch time the animals were killed, and three corneas were evaluated histologi cally. Immunohistochemistry was used to identify proteins associated with t he formation of a basement membrane (laminin) and adhesion complexes (bullo us pemphigoid antigen and collagen VII). Electron microscopy was used to ex amine the tissue-polymer interface for evidence of the assembly of these ad hesive structures. RESULTS. Postoperative epithelial growth began on days 2 to 3, and lenticul es were fully epithelialized by days 5 to 9. Lenticules were clinically wel l tolerated and histology showed epithelium consisting of multiple layers a dherent to the lenticule's surface. Laminin, bullous pemphigoid antigen and collagen VII were identified at the tissue-polymer interface using immunoh istochemistry. Ultrastructural examination showed evidence of assembly of t hese proteins into a recognizable basement membrane and hemidesmosomal plaq ues. CONCLUSIONS. A perfluoropolyether-based polymer coated with collagen I was implanted in the feline cornea and supported epithelial growth that showed signs of persistent adhesion, both clinically and histologically. This poly mer shows potential for ophthalmic applications that require sustained epit helialization.