Corneal cell viability following PRK, LASIK and LASEK: an in–vitro human organculture model

Abstract

Abstract: : Aims:To develop an in–vitro human corneal model to quantify and evaluate the temporal basis of primary and secondary cell death in the cornea following PRK, LASIK and LASEK. Method:We used an in–house and adapted organculture model of the human cornea. Each of a pair of corneas received one of the previously mentioned methods of injury. The fellow cornea was used as a control and both were maintained in organ culture. The viability of cells was determined using live/dead staining at given time points following injury. Overall cellularity was determined using 4–chloromethyl–7–hydroxycoumarin staining and the proliferation marker Ki67 was used to differentiate proliferating cells from those that were simply migrating. Results:A die back of epithelial cells in the periphery following PRK was followed by a latent period before migration of cells to cover the epithelial defect. The time course was similar to in–vivo observations. In LASEK the number of cells surviving the flap procedure and replacement were highly variable. There was an increase in haze where more cells had survived in the flap. In LASIK there was cell death at the posterior flap surface and the anterior surface of the stromal bed. Conclusion:This is a viable in–vitro organculture model of the cornea, which reflects temporal cellular events in–vivo following injury. The model will allow further elucidation of corneal wound healing events and evaluation of emerging pharmaceuticals without company patents.

Keywords: cornea: stroma and keratocytes • wound healing • cornea: epithelium