Analysis of corneal epithelial cells with confocal microscopy after lamellar keratoplasty

Abstract

Purpose the purpose of this study was to analyze morphometry of corneal epithelial cells in normal eyes and after anterior lamellar keratoplasty using confocal microscopy. Methods The combination of the Heidelberg Retina Tomograph II and the Rostock Cornea Module (HRT II/RCM) was used to evaluate the corneal epithelium of 10 eyes of patients who had undergone anterior lamellar keratoplasty (ALK group) and 10 normal eyes (control group). Three epithelial layers per cornea were examined: superficial cell layer, wing cell layer, and basal cell layer. A morphometric analysis software was used to determine area, perimeter, circularity, and Feret diameter of the corneal epithelial cells. Results The mean basal cell area in the central zone was significantly higher (p< 0.001) after ALK than in the control group. After ALK, the mean basal cell area decreased with post-operative time (rS = - 0.42; p = 0.039) but it did not return to normal 24 months after transplantation. Comparison of both groups showed significant differences in cell perimeter, circularity, and Feret diameter of basal cells (p< 0.001). Similar differences were found in wing cell layer. Only few superficial cells could be analyzed on corneal graft (no statistical analysis could be done). Conclusion This study imaged the living human basal epithelium of lamellar grafts, analyzed its structure and highlighted changes in epithelial cells density and morphology. We found an increase in basal cell density between 12 and 30 months. This could be explained by reinnervation of the cornea. Indeed, corneal nerves provide important protective and trophic functions. The basal cell area seems to be a relevant morphometric parameter to assess the corneal epithelium.