Abstract
Purpose:
To investigate the changes in corneal cytology and epithelium in different stages of LSCD using in vivo confocal microscopy (ICM) to establish a more accurate diagnostic algorithm.
Methods:
This was a prospective study, in which a total of 33 eyes diagnosed clinically with LSCD were selected for ICM examination and analyzed retrospectively. Of those 33 eyes, 20 eyes also underwent impression cytology. Ten normal eyes were included as controls for ICM examination. Confocal imaging of the central cornea, the superior, nasal, inferior, and temporal limbus were collected using the Heidelberg Retina Tomograph III Rostock Corneal Module. Epithelial layer thickness, basal cell density, and basal cell diameter were measured in images demonstrating clear epithelial cell morphology. Statistical analysis was evaluated using ANOVA, Kruskal-Wallis tests, and two-tailed T-tests.
Results:
Imaging of epithelial cell morphology in LSCD eyes revealed prominent nuclei, loss of distinct cell borders, and general loss of basal cells with and without preservation of subbasal nerves. In normal eyes, the average epithelial thickness measured by ICM was 47.8 µm, 70.0 µm, 60.2 µm, 58.6 µm, and 62.2 µm in the central cornea, inferior limbus, nasal limbus, superior limbus, and temporal limbus, respectively. When compared to respective normal limbus locations, the epithelial thickness in the limbus affected by LSCD decreased by 27% and 45% in early stage and intermediate stage disease, respectively. Differences between early and intermediate changes in epithelial thickness of the limbus were statistically significant (p=0.04). Nine of the 20 eyes were positive for goblet cells on impression cytology. Goblet cells if present were found irrespective of LSCD stage.
Conclusions:
Our data show that the limbal epithelium becomes progressively thinner in advanced LSCD. Additionally, presence of goblet cells is not a reliable diagnostic marker of the early and intermediate stages of LSCD.
Keywords: 721 stem cells •
482 cornea: epithelium •
550 imaging/image analysis: clinical