Fluorescent in situ Hybridisation (FISH) and Corneal Impression Cytology (CIC) Study of Epithelial Cell Survival Following Keratoplasty

Abstract

Purpose: : to assess corneal epithelial cell survival following keratoplasty .

Methods: : corneal impression cytology was performed on sex-mismatched corneal transplants. Fluorescent in situ hybridization (FISH) with sexual chromosomes specific probes was perfomed in order to identify epithelial cell mosaicisim and therefore allocate the donor or recipient origin of the cells. Twenty-four samples of epithelial cells on 21 eyes of 21 patients transplanted were analyzed. All patients received post-operative treatment using dexamethasone eye drops, with progressive tapering over 18 months and 9 patients also received 2% cyclosporine eye drops.

Results: : Of the 24 other samples, sixty-seven cell nuclei were counted on average per sample. Sex mosaicism were found on thirteen of them, confirming the presence of donor-derived cells at the centre of the graft for up to 211 days post keratoplasty. The disappearance of donor cells seem to be delayed and the average number of persistent cells seem to be greater with using immunosuppressive eye drops as 2% cyclosporine

Conclusions: : The combination of corneal impressions and FISH analysis is a valuable tool without side effects to investigate the presence of epithelial cell mosaicism in sex-mismatched donor transplants. Epithelial cells survived at the centre of the graft for at least 7 months suggesting slower epithelial turnover than classically described.

Keywords: cell survival • cornea: epithelium • fluorescent in situ hybridization