Abstract
Purpose:
To investigate the changes in epithelial basal cell density in different stages of limbal stem cell deficiency (LSCD) using in vivo laser scanning confocal microscopy (ICM).
Methods:
This is a retrospective comparative study. Medical records of 43 eyes diagnosed clinically with LSCD were reviewed. All 43 eyes were then grouped into early, intermediate, and late stage LSCD based on clinical presentation. Eleven normal eyes were included as controls. Confocal imaging of the central cornea, and the superior, nasal, inferior and temporal limbus were collected using Heidelberg Retina Tomograph III Rostock Corneal Module Confocal Microscope. The basal cell density was measured in images demonstrating clear epithelial cell morphology using software from the manufacturer by two independent masked observers. Kruskal-Wallis tests were used for statistical analysis.
Results:
In control eyes, the average basal cell density were 9263.8±597.5, 7042.4±775.2, 6782.2±582.0, 7457.6±355.1, and 7433.6±653.2 cells/mm2 in the central cornea, inferior, nasal, superior, and temporal limbus, respectively. The basal cell density decreased by 31.9% in the cornea and 24.6% in the limbus in LSCD compared to the control (p<0.05). In different stages of LSCD, the corneal basal cell density decreased by 23.4% (p<0.05) in early stage, 36.8% (p<0.05) in intermediate stage and 55.3% (p<0.05) in late stage, respectively compared to that in control. When compared to control, the average basal cell density in all four limbus regions in LSCD decreased by 20.5%, 26.53% and 35.5% in early, intermediate and late stage (all p<0.05), respectively. When compared to the respective normal limbus locations, the basal cell density in the in inferior, nasal, superior, and temporal limbal region affected by LSCDdecreased by 22.2%, 26.5%, 28.2%, and 22.5% (all p<0.05), respectively, and in the unaffected limbal regionby 17.1%, 10.1%, 31.1%, and 25.1% (all p<0.05), respectively.
Conclusions:
These data suggest that basal cell density decreases in LSCD even before the onset of clinical sign.