Assessment of epithelial integrity and cell viability in epithelial flaps prepared with the epi-LASIK procedure

Purpose

To assess the histological integrity and cell viability in epithelial flaps prepared with epikeratomes.

Setting

Department of Ophthalmology, Kyoto Prefectural University of Medicine and The Baptist Eye Clinic, Kyoto, Japan.

Methods

Epithelial flaps were prepared by epi-LASIK surgery. After immediate fixation, they were examined by light and electron microscopy. To assess cell viability in fresh epithelial flaps, biostaining experiments were performed using propidium iodide (PI), calcein-AM, and Hoechst 33342 dye. In addition, some epithelial flaps were organ-cultured for 24 hours.

Results

Light and electron microscopy showed that most of the inspected areas showed nuclei and cytoplasm at significantly reduced density and discontinuity of the basement membrane. Biostaining experiments showed that approximately 90% of the basal cells in epithelial flaps were PI-positive dead cells; organ cultures showed detachment of basal cells from the epithelial flap after 24 hours of incubation.

Conclusion

Most basal cells in epithelial flaps prepared with different epikeratome devices were dead.