Morphology of corneal basal epithelial cells by in vivo slit-scanning confocal microscopy

Purpose. To determine corneal basal epithelial cell density and morphology in a group of normal corneas and corneas with various conditions. Methods. The central corneas of a group of 20 normal patients and 27 other patients who either had refractive surgery or had documented corneal pathology were examined with an in vivo slit-scanning confocal microscope. For all these patients in whom a well-defined basal epithelial layer was visualized, the basal cell density, area, and number of sides per cell were determined using customized software. Results. The average basal cell density was 5,274 575 cells/mm(2), the average cell area was 192 +/- 19.6 muM(2), and the average number of cell sides was 5.5 +/- 0.1 sides for the group of normal controls. There were no statistically significant differences between basal cell density, cell area, or number of sides between the normal group and any of the other groups in which there were four or more patients. Corneas examined from patients with Fuchs' endothelial dystrophy or bullous keratopathy had hyperreflective basal epithelial cell borders. The measurement of the number of cell sides is not reliable using software developed for endothelial cell counting. Conclusion. Corneal basal epithelial cell density and area were found to be remarkably consistent in the variety of corneal disorders that we examined. This finding is further evidence that this aspect of corneal epithelial cell differentiation and maturation is tightly controlled with little variability between individuals even if a corneal condition is present.